Think Snow, Tweet Snow !!!

Saturday, December 29, 2007

2008 Commencement dinner does indeed consist of two courses !!

Finally we can make some progress sorting out this New Years holiday forecast mess. And it certainly seems as if the still pending and adverse January pattern change has been easier to predict and even detail verses the happenings of the next few days.

New Years Eve - A powder day ?
Yes, we have an excellent chance for a few inches anyway. This is the first in a series of two storms that will never come into phase but impact MRG at different times in the New Years holiday period. This first system is generated from the nearly stationary and decaying front which will be draped across the southeast on Sunday. Low pressure will form in the Virginia Tidewater area and proceed northeastward. The track of the storm would seem too far south for any precipitation to reach central and northern Vermont. The area of upward vertical motion with this system however will extend northwestward more than usual allowing the precipitation shield to likewise expand over our beloved location. It is not a guarantee, but snow, assuming my thinking is correct, will begin around midnight on the 31st and continue at a mostly light intensity through mid morning before tapering off. The snow is capable of accumulating 2-5 inches. I am hoping it will be enough for a few freshies at first tracks time but this remains a tricky system capable of producing a few suprises both on the positive and negative side as far as us skiers are concerned.

New Years Day
It will remain dry from late New Years Eve through early New Years Day which means no new snow at first tracks time on January 1st. Snow will not be far away however. The second, in this series of systems appears like an Alberta Clipper on the surface map but is actually a product of this consolidated Pacific Jet talked about at length in the blog. It is also a very dynamic system and is the catylist for this temporary but not insignificant pattern amplification. Synoptic snow from the system arrives in the mid to late morning time frame new years day and should continue for the rest of the ski day. By January 2nd, the system should clear the region but there are indications of a favorable TIS set up allowing for more accumulating snow. Needless to say that January 2nd should be a very winning day since conservatively speaking I can predict 5-10 inches of new snow by opening.

January 2008
Very unfavorable fundamentals continue to loom large starting around January 4th. When looking at the actual behavior of the weather, it has exhibited the ability, at least so far, to fight off the adverse impacts of the prevailing pattern. This is somewhat different than in 2005 where the weather showed zero resistance to the move toward a milder January. The actual weather when compared to expected weather can actually say quite a bit about the seasonal characteristics for what will in this case be the remainder of the winter. The problem however is that the fundamentals such as the consolidated Jet in the Pacific and the unfavorable teleconnection indices have strengthened considerably and the medium range models now suggest that the move toward much above normal temperatures are now less than a week away. My best guess is that the 20 days starting January 4th and ending January 24th are around 10 degrees above normal for interior New England and that the umbrella will be needed on more than one occasion. Although I must say that when it rains in January I refuse to use an umbrella as a protest to mother nature.

Thursday, December 27, 2007

Snow falls heavily a MRG Thursday afternoon leaving no more room for negativity

For all you big city folk that have seen too much snow melt away this Christmas then check out my favorite Vermont weather cam. It is none other than the "Coles Pond Weather Cam" - http://www.robertlyonsphotography.com/webcam/index.php complete with a snow stick and what appears to be a Christmas Wreath. If your watching Thursday afternoon you should be able to witness some heavy snow as what I referred to as a "weak" or "weakening" system impacts central and northern Vermont. This aforementioned system is in fact a fairly benign one but it does deserve credit for bringing more moisture to the north country than I expected. The accumulating snow will end by 11 pm Thursday evening but 3-6 inches of fresh powder will be the end result and will turn Friday into a winning day. Temperatures Friday afternoon could touch or even exceed freezing during the afternoon at the base so first tracks is the way to go.

Friday Night into Saturday System
The system set to impact the region Friday night into Saturday is a stronger one. It is also a very close call as far as outcomes go. The storm will take the lousy St Lawrence Valley route and when combined with the limited amounts of available cold air it is hard to get too optimistic. The storm will however try and re-center itself along the Maine Coast Saturday morning and will mitigate the push of warm air into northern New England. Furthermore, model cross section temperature profiles leave room for hope. My best stab at the situation is this. At no point during the storm will temperatures be warm enough to allow for plain rain, so long as it is precipitating hard enough (the explanation for this will take too long so I won't try). Instead, precipitation will be mostly snow late Friday night with some sleet mixed in on occasion. Total accumulations will range between 3-6 inches again but temperatures could be too close to freezing to support powder. Usually temperatures need to be 30 F or below to support powder at night and 27 F or below for powder during the daylight. When the snow or snow/sleet ends early Saturday then we could see a period of drizzle Saturday morning into the early afternoon with temperatures hovering around the freezing mark.

The New Years holiday period - forecast still hard to pin down but I will try
Sunday will be slightly colder (14 F during the A.M 28 F P.M) which then brings us to the days surrounding the New Years holiday. Overall it looks good for MRG but its a head-ache for us prognosticators. The three day period beginning on the 31st and ending on the 3rd of January appeared to me like a two course meal for MRG (getting some impact from two separate systems). That interpretation appeared as it would be the incorrect one yesterday although the European model continues to occasionally suggest that as a possibility (including in its most recent run). So the revised outlook will consist of this. There are still two systems - a southern branch system that may or may not bring precipitation (snow or a mixed bag) to MRG New Years Eve followed by a powerful Pacific System which will attack from the west-northwest and bring both synoptic snow and TIS to MRG during the January 1st-3rd time frame. This second system marks the temporary but sizable jet amplification which will occur in this same time frame. It will mean a return to some very wintry weather in Vermont but again its temporary.

No change on the outlook for January

I have no good news for the period after January 4th which means everything in my last post regarding that time frame still applies. The pattern is in fact dangerously similar to January of '06 and like that one could turn out to be one of the milder January's on record. Consistent with the title of the post, I have little to no room for negativity and there is certainly room for excitement regarding the next 7 days which needed and still probably needs some serious clarification.

Tuesday, December 25, 2007

Good news is hard to find on Christmas Day but I am looking

Merry Christmas !!! Sunday's rain knocked the snow depth near the Mt. Mansfield Summit to 48 inches, down 8 from its peak of near 56 inches and still well above average for this time of the year. It is the quality of the snow which took the biggest hit however since crust now plagues the Vermont Woods from Stratton to Jay Peak. The most dominant feature going forward has been, is now and will be the consolidated and very powerful jet in the northeast Pacific Ocean. The valve controlling the flow of arctic air into the U.S. has been temporarily shut as a result and now the longwave pattern is sending storms on a perilous course. La Nina has brought its chickens home to roost and going forward into January looms an uphill pattern as the now marginally unfavoarable pattern has a chance to turn downright awful after January 4th. Until that time we have a chance at scoring some individual victories and we will get a chance to detail those in this post.

Through Saturday
Calm winds and slightly above average temperatures will make for some comfortable weather as far as skiing is concerned both Wednesday and Thursday. Thursday will be the day which features more in the way of clouds and eventually some light snow late in the day. There is a good chance this light snow continues into the night dusting MRG with a very light accumulation (1-3 inches). The disturbance responsible for the light snow is a very weak one but will be followed quickly by more organized weather system which approaches late Friday. This, stronger weather system will take dead aim at Lake Huron which to be blunt is a deplorable track in terms of bringing new snow to Vermont. Consequently, there will be a push of warm air ahead of the passage of this storm and it will be tough to keep precpitation in the frozen variety. Some of this "warming" will get cut off at the pass as this storm will try desperately to re-center itself off the New England coast. This is a very close call with a few very different options still on the table. If the coastal "cyclogenesis" can occur efficiently then precipation would ramain mostly snow even if more of it gets confined to Maine. The other option would involve a period of sleet or freezing rain before a return to snow or flurries occurs Saturday.

What about those individual victories ??
Our best hope for big time new snow comes around the time of New Years as the pattern takes a temporary turn for the more amplfied thanks largely to the Davis Straits blocking which is trying to ease the pain of this regime. It becomes rather complicated because there are two weather systems in this time frame, a very tight temperature gradient and considerable disagreement amongst the computer guidance. The outcome is therefore very up for grabs and extremely sensitive to slight changes in the track of either weather system. Precipitation from the first storm would arrive late on Sunday although the American model suggests there is little if any impact from this system. Assuming we do get an impact (which is about 60%) then precipitation could be snow, mixed, precpitation, rain or all three depending on the track and evolution of this system. The second system will hypothetically impact the region on January 2nd or 3rd and is of the "snow or no" variety which means that the chance for rain is limited. This second system is a product of the clash between La Nina's southeast ridge and the push of colder temeperatures resulting from the temporary pattern amplification. The storm will pass to MRG's south which is a good for keeping precipitation in the form of snow but if the storm were to travel too far south then little or no impact would be the result.

The taste is sour not sweet after January 4th
After January 4th, the pattern has a very ugly and bitter appearance. The taste is not horse radish either which I can eat in large quantities on almost anything but rather some dairy product still sitting in your fridge that has seen better days. Both the european and american ensemble guidance now indicate a very large signal of warmth after January 4th across the eastern U.S. and southeast Canada. The driving force of such a pattern is a combination of of the persistent and very agitating jet in the northeast Pacific and some of the teleconnection indices, specifically the AO, which has turned quite unfavorable in recent days (much more than what was expected just a week ago). Regarding the AO, there is actually a time gap between what the value of the index and the impact of that index on the weather at MRG. For instance the AO was negative for the last half of November and into early December but then turned postive by December 6th. The weather at MRG was was golden from late November to the Winter Solstice. I will therefore offer that the AO index which is currently a positive 2 will ultimately have a much more negative impact on the weather going forward into early January. We can certainly hope for better results verses the one I am suggesting but I am not optimistic as of now.

Merry Christmas again to everybody out there. Be safe this holiday season !!

Friday, December 21, 2007

Borrowed time is running out

It was actually a slight misrepresentation to call this "the last few days of the favorable December pattern". The weather pattern has in fact already turned and evidence of this can be found in Whistler-Blackcomb's snowfall report which shows a new 40 inches over the past 7 days. This is a consequence of the very consolidated Pacific Jet Stream, fueled by the La Nina. The same jet which is working rapidly to erode the remnants of the cold which was produced by the early December negative AO.

Does anybody really want any additional details about Sunday's rain event ? If so then I suppose you can read on but if not feel free to skip down, I won't be offended. The rain will arrive later in the day Sunday and some areas could see a period of freezing rain before southerly winds push temperatures regionally above freezing later Sunday evening. Temperatures will climb to about 40 degrees overnight and rainfall totals will range between a half an inch to eight tenths of an inch.

I did mention in the last post the possibility of some terrain induced snow (TIS) on Christmas Eve and Christmas Day and this is still a likely outcome I am happy to say. The culprit is a fairly tight pocket of favorable upper air dynamics which will produce enough instability over the high terrain of Vermont for a few inches of much needed snow by early X-Mas day (I don't think much falls on Christmas Eve however). Later in the week looms another conundrum however as another storm takes the highway to the danger zone (credit - Kenny Loggins). Its too early to for a specific outcome but I am not encouraged at our chances given the lack of available cold air. I am hoping this system late next week simply doesn't come together and avoids us completely.

If there is a sliver of light in all this looking toward New Years Day and beyond its this. Ensembles are indicating a healthy area of jet stream blocking over the Davis Straits even as we continue to hear the roar of a furious Pacific Jet. What I hope this causes is the Jet Stream to split somewhat across the eastern United States. We won't get any real cold air even in this scenario but it would help to keep the storm track farther south which is one way to sneak through this proverbial thorn-brush.

I got one more update prior to Christmas but if this is your last read then a merry Christmas and a happy Winter Solstice to everyone.

Tuesday, December 18, 2007

Clipper me this ! At least 5-10 more inches of powder for Thursday first tracks

No, those innocent moisture-starved clipper systems are certain short on drama but they do consistently deliver. Powder that is, particularly to the high terrain of Vermont and is what this one will do. This is a system we able to key on fairly early in the ball game but up until now it was a bit uncertain as to which day would feature the most new powder to ski in. The answer is Thursday. Snow from this vigorous upper air disturbance will approach from the northwest and begin falling late in the ski day Wednesday. MRG should see snow much of the night and into Thursday morning and accumulations will be enhanced by the effects of the local oragraphy. Do you want my advice ? Take the day off Thursday and get your rear end to MRG and enjoy the last days of this favorable pattern. 5-10 inches of snow from this clipper atop the already fallen December snow will make Thursday one of the best December ski days at Mad River since 2002.

La Nina is hunting is down


Now I am well aware of our good fortune so far this December. The winter of '07-'08 has begun much the way '06-'07 ended. I am also well aware of my seasonal prediction and I can say one thing regarding that. I am not changing it - The forecast must be judged on its content prior to the season and I will happily taste crow should the prediction go up in a plume of smoke. La Nina, by the way, has maintained its moderate strength and is quite articulate in its speakings to the current weather pattern. The biggest feature across the Western Hemisphere is a large upper air trough in the Gulf of Alaska with a ridge directly underneath it northeast of Hawaii. The two features when put together create a powerful jet which will work quite efficiently at ridding mid-latitude North America of its arctic air. New England, in fact, will be one of the last places in the U.S. to be encompassed by cold weather as early as this Friday. Looking for a silver lining ? I can give you the following. Teleconnection indices are not overwhelmingly unfavorable at face value. The AO is forecast to run Neutral, the NAO is indicated to even go negative (favorable) leaving the PNA as the only major teleconnection index to be consistently working against us (it will be running negative). Translation - We could dodge a few bullets but there will be numerous of them around to avoid.

The Sunday Dilemma

The first effects of this adverse shift in the global pattern will be a bullet that will prove very difficult to avoid. On Sunday the arctic cold will move off the Atlantic Coast and in doing so become quite stale. As this is happening a low pressure center will take dead aim on the St. Lawrence valley and push warm air deep into the northeast U.S. and even into southeast Canada. The result on Sunday will be freezing rain which will develop during the day Sunday and ultimately go to plain rain for a period of time Sunday night. I do not believe temperatures will get especially warm during this event and thus the deep early season base will see little depletion. With freezing rain or rain however comes the crust once a re-freezing occurs and I believe this happens quickly on Christmas Eve as colder air arrives in the wake of the storm. This colder air combined with marginally favorable dynamics may be enough to induce some TIS (Terrain Induced Snow) into X-Mas day but its too early talk accumulations. It is possible that we could see some however and this could bring some serious help to Christmas Day skiing.

X-Mas to New Years

During the last week of December, much of the country will be be covered by Pacific Air and it is my thinking that much of New England will see above average temperatures in spite of any brief intrusion of colder air on December 24th - December 26th. The models are going off on some expected tangents in this time frame with the American GFS model showing a more amplified pattern consisting of a more amplified negative NAO. The results of such a regime would be temperatures which are closer to normal and some new snow. The European however suggests much more in the way of milder weather and much more in the way of rain. All of the ensemble data confirms that it will be a very difficult pattern for us to navigate through with several potential land mines going into early January.

Sunday, December 16, 2007

Heavy snow Sunday Night to bring storm total to near 2 feet

The mixed precipitation or sleet is finished at Mad River and as it turned out, the mountain got rather lucky since the lull coincided well with the warmest part of the storm. How does the saying go ? If you don't have something nice to say don't say anything at all. My saying is more along the lines of "If it isn't cold enough to snow then it might as well not precipitate at all. I don't know about you but the two sayings sound synonymous to me. Our winter storm is intensifying very rapidly having just reached the Maine coast as of 6:30 pm Sunday. As a result, there is a very healthy conveyor of snow pivoting eastward that is set to deliver an additional 10-14 inches to the mountain tonight. No doubt that with all the wind received Sunday and more expected Sunday night, there will be plenty of fresh tracks to be had even late into the day Monday. Snow will taper to flurries by morning but the blustery conditions will continue.

We got another promising clipper system on Wednesday as well. Clipper's are inherently short on moisture but we do happen to be in a fairly good spot to get the most out of this one. Snow will begin during the morning and persist into the evening totaling as much as 6 inches before giving way to a reinforcing shot of colder weather. This reinforcing shot may be the last of the arctic air for a little off as we will be defending against a rather adverse pattern from Christmas Eve forward. More details on that to follow.

Saturday, December 15, 2007

Winter Storm Forecast: Fine Tuned

There are a few important items requiring clarification regarding our upcoming winter storm. First of all, the start time which was advertised in the blog as 8 am needs to be pushed up to 5 am (give or take a few hours). This obviously means that snow accumulations for first tracks time on Sunday which was indicated to an inch or less may turn out to be 2 or 3 inches. Between 8 am and noon we could see some snowfall rates of 2 inches an hour meaning that snow accumulations by early afternoon could approach 10 inches

It will be around the early afternoon when the much talked about winter storm will begin transitioning much of its energy from the original low pressure center which at that time will be over eastern Pennsylvania to what will ultimately be the Maine coast. This time of transition will be the "warm" period of the storm when the critical above freezing layer reaches central and even northern Vermont. The change to sleet at MRG will occur between 12 and 2 pm and will last around 6 hours. It is possible even that precipitation subsides for a time and we get a "lull" within the storm. As the storm "bombs" on the Maine coast Sunday evening, precipitation will go back to snow and it could again get quite heavy before tapering off Sunday night or Monday morning. I am sticking by the total accumulation numbers of 15-30 inches although my feeling is the 6 hours of sleet hurts our chances of getting much over 2 feet.

Friday, December 14, 2007

Whats that I hear ?? The sweet sound of the big dog barking !!! Mad River to get clobbered with 16-30 inches of Snow and some Sleet Sunday/Monday

If that ski jacket you own comes with one of those powder skirts you better make sure it works because you can put it to use this weekend. The ghosts of Valentines Day have been put to work and are producing an event this Sunday which is very analogous to February 14th. Who would've thunk it !! Certainly not me since apparently someone injected with me the "glass-half-empty steroid" prior to that pre-season report I gave last month. But who really cares what was said and when. Without a doubt the best responsibility I have maintaining this blog is to hype a storm such as the likes of this one.

The Storm
Dig back through the archives of the blog or in the recesses of your mind and recall that the Valentines Day Blizzard deepened to about 978 mb and tracked directly over the city of Boston. It was a juicy system also supported with moisture from the gulf, amplifying/digging upper air dynamics and a healthy supply of fresh low level cold air from eastern Canada. This system has about every part of what Valentines Day had including the cold air which will arrive on brisk northwest winds by Saturday morning. The difference would seem small but it does make the forecast a bit trickier. This storm, according to the models will track from Philadelphia, to Hartford to Worcester to Portland, Maine. In other words, if things go according to the plan, the storm tracks west of Boston bringing the above freezing temperatures in the mid-layers of the troposphere closer and eventually over MRG. So recall that the sweet spot for Valentines Day storm was at the base of the Single Chair and I marked the spot with some red tape if anyone wants to take a look (joke). For this event, the sweet spot will probably be closer to Mt. Marcy in the Adirondacks. That is quite alright though because Mt Marcy is really not that far away.

The Details
High clouds from the rapidly strengthening system may arrive as early as the afternoon Saturday which will help to keep temperatures at or below 10. Calm winds and the new snow received throughout this past week will help to make it a pretty good day to ski. Good visibility will do wonders for the view as well (won't be much of a view on Sunday). My guess right now is that the snow commences around 8 am Sunday with a minimal accumulation by first tracks time if any at all. I know a few inches would be nice but the timing here isn't bad since the first 6-8 hours of the storm will be the part which does not feature as much wind thus putting us less at risk for any wind holds. Believe me once this snow starts coming down by mid-morning it will accumulate at a rate of between 2-3 inches an hour and this should persist throughout the end of the day. In other words, it will be all about last tracks since that 3:30 pm run I know everyone plans to take will feature nearly a foot of new powder to ski in. In all seriousness though, please drive safe if your traveling Sunday and consider staying at a lodge and taking the day off Monday. It will be a epic day to ski but a miserable day to travel particularly during the evening when the wind intensifies. The interstates should improve dramatically by late Monday.

Sleet Factor
Some have accused me of sleet-a-phobia and I will argue that I have none. I am just an east coast realist as far as weather is concerned and I have also looked at the temperature cross sections about 10 different ways. The change to sleet will occur during the evening and last for a period of around 3-6 hours Sunday night before we go back to a period snow prior to first tracks Monday. Snow and sleet accumulations will be in the 16-30 inch range with much predicated on the duration of the sleet. We will not get any freezing rain however which means none of that dreaded breakable crust. What I can say is that this storm assuredly puts the mountain in fantastic shape heading into the X-Mas holiday as far as the base is concerned.

Next Week and Beyond

The snow on Monday will taper to snow showers and flurries. It will be blustery and quite chilly as it always is following a big storm such as this. On Tuesday the winds diminish but remains cold with temperatures below zero in the morning and in the teens during the afternoon. On Wednesday, a clipper system will bring limited amounts of moisture to the region which will likely be deposited as a small accumulation of snow and giving us a powder day (either Wednesday or Thursday).

Now I hinted at a potential pattern change of a possible adverse variety late next week and indeed some of the teleconnection indices specifically the PNA will turn unfavorable by the winter solstice. Data however from both the medium range model guidance and the ensembles seems to be delaying the effects of this pattern change in the northeast and is suggesting that the turn to milder weather will be felt most dramatically in the plains. This is certainly encouraging for the time being and we will have to hope that an ample supply of cold air is still available X-Mas weekend prior to the arrival of the next system which still has a zillion possibilities as far as its impacts on MRG are concerned. More will follow on this but for now I will stay focused on the storm and will provide another/shorter update regarding that sometime on Saturday.

Wednesday, December 12, 2007

Thursday storm disappoints but the ghosts of the Valentines Day Blizzard 2007 are brewing up a sequel this Sunday !!!!

I suppose it was very foolish of me to stray from the philosophy which worked so well during the winter of 06-07. There was a disagreement on how the weather would play out this week and the European model said this and the American model said that and in light of some of the recent struggles which plagued the European model through the summer and fall I was baited into fading its reliability during the winter. I like my crow served with cranberry sauce thank you ! Actually I would prefer my crow served with about 2 feet of snow and there and things are in the works to make that a reality if you can believe it.

The European had the right idea all along. It had the right idea Sunday and had the right idea Monday when I issued the last update and now the other model guidance is in the process of jumping on the bandwagon. Wasn't it somewhere that I heard that all the cool people show up late to the party ?? Perhaps that only applies to America and not Europe. Actually us weathergeeks are often joked on for rarely getting invited to the party at all though we can still be fun and festive company, like Phillip Seymour Hoffman in Twister who was great as a tornado-chasing weather weenie in a movie full of bad science.

Thursday event fizzles to a few inches by Friday morning
Thursday's system was a disjointed one to begin and because it is a fast moving, it never had huge potential. As it turns out, the two pieces that were suppose to make up this weather system will never fully align. One storm, containing the bulk of the moisture will move quickly out of the Tennessee Valley early Thursday and be south of Long Island by the evening, too far south for any real impact on MRG. The other is a rather potent Alberta Clipper which marks the leading edge of a re-enforcing shot of cold air which will trail the aforementioned moisture-rich system to the south. Most of central and northern Vermont can expect snow from this trailing system but mainly late on Thursday or Thursday night. The dynamics from the clipper will induce snow showers and snow squalls Friday. Accumulations should be considerably lower than what was advertised in the last update, probably in the 2-6 inch range between Thursday night and Friday.

Sunday contains the real potential
The jet stream will form a nice confluence area over the Canadian Maritimes providing interior New England with a chilly day Saturday including high temperatures which struggle to get past 10 on the mountain although the winds will be relatively calm. This confluence area is a key ingredient for what is to follow on Sunday as a major weather system approaches from the southwest. It is rather incredible actually to look at the upper air and surface maps and see so many things which are strikingly similar to Valentines Day 2007, a day which probably should be memorialized at MRG. In truth, it is dangerous for a prognosticator to make such analogies 4 days from the event and some key details are likely to change over the course of the next few days. With that said, there is very good agreement concerning a big noreaster this weekend, one which will provide the coast with a mix of snow, sleet, freezing rain and ice and one which will deal interior New England and much of northern New York a sizable snow event (and wind) or one that can be measured in feet. I don't want to get carried away here because it is early and hype as a tendency to fizzle. Another update in a day or two can probably zoom in on the details a little closer and we can go to work from there.

The 20th or the 21st continues to be the date of a potential pattern change with two of the three teleconnection indices turning against us. The most dominant feature according to all indications will be a big trough in the northeast Pacific Ocean and over British Columbia. The snow cover which could be fairly deep by then could mitigate any warm-up for a time. Hopefully we can also avoid any X-Mas rain drops.

Monday, December 10, 2007

Is the Airmass Clash leading to a Thursday Winter Storm Bash ??

La Nina often means some serious pain for our skiing friends south of the Mason-Dixon line and the jet stream's southeast ridge this week promises to bring another chapter of mild weather and rain to those locations. There is typically more drama concerning the impacts of the southeast ridge on Vermont and surrounding New England locations since the storm track is often lifted northward with many systems taking direct aim at General Stark and his Green Mountain companions. The arctic air provided courtesy of the negative Arctic Oscillation (AO) will take to the battlefield against La Nina's ultimate weapon (the aforementioned southeast ridge) leading hopefully to some very positive consequences as far as the upcoming weekend is concerned. I realize the drama was poured on a little thick but the Thursday storm threat is real and we should be excited to see winter storm potential such as this so early in the season.

Tuesday Teaser !!
Prior to Thursday, MRG will be impacted by what should be a rather disorganized area of precipitation late Tuesday or Tuesday night. Temperatures, particularly in the valley locations on Tuesday will warm quite significantly and in many cases may exceed the freezing mark. Precipitation in these areas may fall as a mix for a time before going to snow overnight. Aries the higher terrain, such as MRG, precipitation will be all snow and accumulations have a chance to exceed 4 inches. The snow will fall in association with a fast moving arctic cold front which will clear the areas early Wednesday and will end all precipitation by the middle to late morning. The clear skies, snow cover and light winds will set the stage for one of the colder nights of the season Wednesday night before what we hope will be some fun and games for Thursday.

Thursday's Storm !!

The fast-moving aspect of weather systems within this ambient pattern presents a challenge to the prognosticators and the Thursday's situation is no exception. The medium range guidance has been keying on a system in the southern Plains gathering moisture very quickly Wednesday night before speeding northeastward. Although it seems likely this will happen in some variety meaning the increase in clouds and the eventual accumulation of snow, the exact timing will have a big say on the end result. The usually reliable European model has been unusually unreliable for much of the fall and it seems somewhat pessimistic on moisture reaching the central and northern sections of Vermont. The GFS and Canadian model tell a different and much more appealing tale and will be one I will choose to lean to at this time. This solution has the system in question tracking from southern Illinois to southern New England. Snow would develop during the day and would fall heavily during much of the afternoon accumulating 8-16 inches as a conservative guess. Wednesday's update will have to take the more specific step on addressing accumulations and a more smaller window of start times and stop times.

The Weekend
Although this European model seems unwilling to give us any love for Thursday, it does follow up with a humdinger of a noreaster for the weekend. Unfortunately it is not good scientific practice to go buffet style as far as sifting through the model data is concerned and we will not do that here. For now we will stick to the idea that the dynamics and upper air jet stream support stemming from Thursday's storm will linger into the weekend and will keep the opportunity for new snow through Saturday when finally the commencement of a slight warming trend will act as a stabilizer for the atmosphere. Not bad though for a December 14-15 weekend !!

The Xmas week questions are beginning to role my way also. Don't want to get too distracted with that right now since I am exhausted but I will say though that the ensembles are not showing a fundamentally supportive pattern for cold and new snow beginning around the time for the winter solstice with the main axis of the upper air trough shifting in the west. In short, I am expecting a more adverse change in the pattern within a few days of the Solstice and we will have to hope that the arctic cold provided by the negative AO index can hold off such a change as long as possible. Even if the cold does relinquish significantly, we will not see a repeat of 06 when the mild weather completely depleted an already limited base.

Thursday, December 6, 2007

Mad River is off and running - Challenges lay ahead

A fiercely negative Arctic Oscillation (AO) brought some big time love to Vermont and helped give MRG one of the earliest opening day's I can remember this decade. It was also a big slap in the face to the seasonal forecast but I have no problem with that. The prospects for new snow over the next few days including the weekend do not look great as the atmosphere will become fairly stable as a ridge in the jet stream becomes established across the southeast. As I mentioned in the previous post, the southeast ridge is what La Nina does best and it forces the mountain to go on the defensive in terms of protecting its base and keeping temperatures below freezing.

Specifically for the weekend, we do have a the passing of a very benign weather system late Friday. It would obviously nice to squeeze out a few inches prior to first tracks time on Saturday but a dusting to 2 inches is the most reasonable guess I can make. Saturday's temps may approach 30 in the afternoon. On Sunday, we will be blessed with some great visibility (either clear skies or a high overcast) but low level cold will push temps to near zero in the morning while afternoon readings only approach 20.

By early next week, the baraclinic zone will be directly over Mad River Glen and much of Vermont. To put it plainly the baraclinic zone refers to the region where warm air is directly clashing with cold air thus producing a big contrast in temperatures over a relatively narrow region. It also is the region where overrrunning precipitation is often focused. The challenge involves keeping all this precipitation in the form of snow which could prove to be quite difficult. The best I can do in terms of offering out specifics now is to say that precipitation, if we get any, on Monday and Monday night will be in the form of snow. By Wednesday a much more organized area of low pressure will approach along this baraclinic area and threaten to push more warmth into central and northern Vermont. Models are suggesting that we do have a chance at keeping enough low level around to prevent a move to above freezing temperatures and plain rain. It will be tough however to keep precipitation all snow during the middle of next week. Again, we are playing defense.

By late next week and into the weekend, we are back into more widespread cold and also some instability. This means that some accumulating TIS is likely before the weekend of the 14th and 15th. There also is a chance that we are impacted by a more organized weather system. We can't really expand on that however until the next update. Enjoy the snow and the early December skiing !!!

Saturday, December 1, 2007

Negative AO means a strong early December start

Fundamentally, there are few allies more dependable than a negative Arctic Oscilation. Send the cold down to the mid-lattitudes and keep the relative warmth near the poles. A whole winter consisting of such a pattern and there would be no need for a single chair weather blog since every other day would be a powder day. It is encouraging to see the '07-'08 winter begin as the '06-'07 winter ended but the deck remains stacked against us unlike it was last year.

Not only do we have some cold courtesy of the AO index, but we also have a storm. One which should begin as snow late Sunday, change to a period of sleet for a time early Monday and then go back to a longer period of snow later Monday into Tuesday. Much of the snow later Monday into Tuesday will be of the terrain induced variety and I will refer to this as TIS (Terrain induced snow) for the sake of concision. It is a fairly good set-up for TIS actually and I would not be surprised to see MRG tally 10-20 inches in the period beginning late Sunday and ending early Wednesday. No sense in getting more specific with the mountain closed but if new snow totals do indeed fall in this range it could be enough to induce an opening day announcement from the powers that be.

The AO is expected to remain on the negative side of zero for the next 10 days although models are showing a dreaded strengthening of the southeast ridge by next weekend. This is going to be a tough animal to tame this winter as the prevelance of the southeast ridge is correlated to the La Nina. It will be a bullet we will need to dodge next weekend or else its mild weather and perhaps even some rain. I will check back early next week to see if MRG plans an opening and will update the blog accordingly.

Sunday, November 18, 2007

Back 4 More !! – Seasonal Outlook for ’07-‘08

I always say that the approval rating of a weather guy is only as good as the weather he/she predicts. If I can’t forecast sunshine and pleasant temperatures on your wedding day then I can’t forecast my way out of a paper bag. Likewise, if I can’t predict a snowy winter for the Mad River Glen faithful then perhaps the powers that be should find someone who can ;). Don’t feel bad the sentiment is perfectly normal and I am very used to it. I am proud to be “back 4 more” or a 4th season of blog duties. It’s been a lot of fun and it’s the greatest audience. And for all those skiers who visit the blog but are still loyal to Sugarbush, Stowe or Killington; well, we are still happy to have you but would be even happier to see you buried in powder on Paradise. And for our snowboarders out there, we are happy to have you too, but I can’t provide regular updates on snowmaking, or half-pipe making in November. You will just have to get your weather from other sources until the opening bell at MRG is a few days from sounding.

If the opening sentence sounds to you like a disclaimer then your intuition is correct. There is very little to be excited about when looking at the upcoming winter from the perspective of our favorite seasonal variables. That being said, I don’t think I can do much better than 60 percent on these seasonal outlooks and I have for the most part, called the last three winters correct. This means I am overdue for a serious bust. It took one heck of a finish in 2007 to get that one into the win column but in the end the mountain tallied nearly 300 inches of snow and temperatures were slightly above normal in accordance with the pre-season prediction. There was a gentlemen (I forgot his name) who emailed me after the seasonal forecast last year and by using his favorite folklore, predicted a slow start to the winter followed by a big finish. He was even more right and should receive some well-deserved recognition.

1) ENSO – It has delivered us a low blow with the re-development of what could turn out to be a nasty La Nina.

2000-2001 quite possibly could have been the most epic winter in the history of Mad River Glen. That winter included a storm in early March which dumped 50-70 inches on much of the Green Mountain spine. Believe it or not, ENSO conditions that winter were that of a weak La Nina. 1995-1996 also featured a weak La Nina and MRG was graced with Mother Nature’s better half for much of the winter. Moderate to strong La Nina’s, such as the one threatening to prevail this winter, do not have a particularly good relationship with us MRG skiers. Some of the stronger La Nina winters include 1999-2000, 1998-1999, 1988-1989 and a string of winters during the early to middle 1970’s. Vermont typically fairs substantially better than locations further south during moderate to strong La Nina’s. Locations such as West Virginia for instance often feel the effects of a potent southeast ridge in the Jet Stream, which aside from making it incredibly mild for long stretches of the winter, also deflect storms to the north and west, which means little if any natural snow. Snow often does fall in New England but very often the snow events also include mixed precipitation or rain. We were blessed with 58 days during the second half of the 06-07-ski season without rain, an occurrence, which made last season one of my personal favorites. It is very unlikely that we will even get 30 days without rain unless La Nina subsides. Currently the critical 3&4 Nino regions are seeing SSTs of 1.3 C degrees below normal, which in a quantitative assessment is as a moderate to borderline strong La Nina. SST’s would need to warm to at least within a degree of Celsius before we can categorize the ENSO event as weak.

Round 1 - The current state of La Nina favors below normal snow and normal temperatures. A La Nina such as this one is often a knockout upper cut to the ski areas in the Middle-Atlantic but interior New England does tend to fair better but far from great.

2) Pacific Decadal Oscillation (PDO) – This is measured as an index and the October value was an ugly -1.45.

We can again start this part of the analysis on a positive note by recalling the winter of 1970-1971. This is one winter that ranks right up with 2000-2001 in the epic category and a winter where the PDO index was close to -1.70 (see link below).

http://jisao.washington.edu/pdo/PDO.latest

In general, however, there has been a correlation between the index of the PDO and the prevailing weather pattern for eastern North America and this correlation would have us hoping for a more positive index as opposed to the -1.45 recently recorded. There is some very general information on the PDO that can be obtained through Wikepedia.

http://en.wikipedia.org/wiki/Pacific_decadal_oscillation

More specific information including the page that actually tracks the indices is included here.

http://jisao.washington.edu/pdo/

Both the index of the PDO and the ENSO have been known to change quite abruptly even at the 11th hour. It is often why many seasonal forecasts which are made too early in the autumn go belly up. This seasonal outlook has been created fairly late in the ball game but these variables still have some time to do some shifting. Unless they do however I think we are in trouble.

Round 2 – The current negative index of the PDO favors both below normal snow and above normal temperatures.


3) Snow cover area – One of my favorite seasonal indicators when looked at hemispherically. When measured in millions of square KM the normal snow cover area in October is 17.7. Last year we recorded an October number of 19.8 but this year its closer to 16.3. Yuck !!

The measure of a winter from the standpoint of temperature is usually determined by the following tongue twister. The strength of the cold embedded within the cold pattern. The “strength of the cold” refers to the arctic air originating near the poles. Arctic air of a stronger intensity in a fundamentally colder than normal pattern may mean the difference between 5 degrees and 15 degrees below normal. Likewise, a normal pattern may be 5 degrees below normal instead of 5 degrees above and the adverse impacts of an above normal pattern may very well be significantly mitigated. The opposite if of course true if the air with polar origins is weaker than expected. It is important to examine this issue in any seasonal outlook because the most basic assumption that needs to be made is that the winter will consist of both fundamentally mild or unfavorable patterns for us MRG skiers and fundamentally cold or favorable patterns. 2006-2007 was a winter where us New Englanders got a good look at both sides of the spectrum.

So what does snow cover in October indicate about the measure of cold in an upcoming winter? It has to do with cold pooling efficiency. A greater coverage of snow in the polar regions early in the year will allow arctic air to strengthen quicker and reach a greater maximum intensity. An analogy can be drawn between the effects of snow cover on arctic air and the effects of anomalously warm water has on hurricanes. 2005, the year which featured Hurricane Katrina among many other land-falling storms, was defined by warmer than average water temperatures in the Caribbean and Gulf of Mexico. Storms traveling through these areas strengthened quicker and reached a greater maximum intensity. Arctic air has a similar relationship with snow cover.

Round 3 - 16.3 millions of square km is a very ugly number snow cover number. It is worse in fact than what we saw in the autumn months of 2001 and in 2005, which preceded two not-so-friendly winters. To put it mildly, the data favors above normal temperatures and when combined with some of the aforementioned indicators, I would be very surprised to see temperatures average below normal for the December to March period.

The Prediction – No spin here at the Single Chair Weather Blog. We tell it like it is though admittedly I am hoping to be dead wrong. Temperatures for the season will average above normal and significantly so. When I say significant I mean at least 3 degrees above normal for the December through March period. In terms of snow, I predicted 300 inches last year against an average of 260. This year I expect less than 220. Sorry for the lack of hype but I always like to say, if you keep expectations at a minimum you open the floor for a few pleasant surprises.

Thursday, April 5, 2007

Winter returns and will give MRG a true Easter grand finale !!!

And a grand finale it will be for both the mountain and for the 06-07 edition of the Single Chair Weather Blog. Sorry for the less than frequent updating but the uncertain status of the mountain gives little incentive for continuous updates (although the weather has provided incentive enough). The general themes from the update a week ago were very much on the ball although I freely admit that it was almost shocking to see snow fall through much of the day yesterday when a few days prior it looked like a 45 degree rain was almost certain. Thus the forecast for this past Wednesday was first class bust. This is another example of how the war between warm vs cold and rain vs snow is fought on different battle lines every year with different coefficients and different variable inputs. In a final analysis, the cold and snow has won many victories in 2007 compared to the few if any won in 2006.

Cold in April can mean big things for the New England high country
The skinny on the weekend is for winter-like cold and terrain induced snow which will continue sporadically through early next week when at that point the seasonal snowfall will be very close to average thus finishing off our incredible 2007 comeback. For a minute here let me just rave about what can be accomplished when cold weather combined with deep upper trough settles favorably over Vermont in April. Instability just thrives in April and the reason is this. The sun angle is obviously higher providing more hours of daylight and more time to warm the earth's surface. The middle and upper level layers of the atmosphere are slower to respond to the seasonal changes and thus we have a climatologically more unstable period (warmer at the surface, colder aloft) in the spring and a likewise more stable climatological period in the fall. It is the same concept behind the severe weather season in the plains when tornadoes are the most frequent and most destructive. It may sound confusing and thats because like many things in life it is a relative game.

1-2 additional feet and a few powder days
So with that little tangent fully exercised I can continue with a forecast. It must be prefaced however the rapidly becoming famous "subject to bust" disclaimer which should automatically apply to terrain induced snow events since they are so tricky to predict accurately. With the cold weather now becoming firmly entrenched the big question now becomes when and how much terrain induced snow will fall. I looked at as many things as I could Thursday morning and decided that the snow should fall heaviest Thursday (the time of this update) and Thursday night and then again beginning late Saturday through Sunday and Monday. The period beginning Friday and ending early Saturday appears to be the time frame where the region will be in between the two jet amplifications. I think this translates to a forecast where heavier snow showers Thursday and Thursday night taper to flurries Friday, Friday Night and early Saturday before snow showers re-intensify later Saturday and persist through Sunday, Sunday night and even Monday. Yikes ! Say that 3 times fast ! The powder days, and they will be powder days by the way given the intensity of this very impressive April cold, given this forecast will be Friday, Sunday and Monday. Snowfall has already totaled close to 10 inches as of midday Thursday and I am conservatively expecting an additional 1-2 feet by late Monday. 6-12 of these inches may very well fall by first tracks time on Friday.

If we can convince the powers that be at MRG to stay open later than Easter Sunday, there could another big easter egg discovery courtesy of mother nature. It is a bit early and medium range computer models are not exactly aligned as of yet but the possibility of a mid to late week storm exists producing snowfall of the more synoptic (as opposed to the fluffy terrain) variety.

With that I will sign off for the season. If your heading out this weekend dress warm. The forecast may say 30's for the valley locations but temps will be substantially colder on the mountain (20's). Thanks to all the readers for the interest in both the blog and skiing at MRG. We will ramp it up again for another season late this upcoming fall. Until then, enjoy the remainder of spring and upcoming summer.

-Joshua Fox
Single Chair Weather Blog

Thursday, March 29, 2007

Rain, but not until after the weekend; Big time April cold may freeze Easter Eggs

Those in the know say that the tree sap runs best on dry days when temperatures start at sub-freezing levels but then warm to well above freezing. This is essentially what mother nature has planned for the weekend. Clear skies Friday night and a slackening wind will allow temperatures to fall to as low as 15 in parts of the Mad River Valley. At lift opening Saturday, readings are likely to remain in the 20's until much of the mountain sees the above freezing temperatures by noon under plenty of sunshine. The afternoon Saturday should be delightful with soft snow on much of the mountain and temperatures between 35 (summit) and 45 base. Sunday, April Fools, will be a repeat of sorts only that temperatures during the day will respond quicker to the early morning sun before that sun fades behind increasing high clouds in the afternoon. I am optimistic that Sunday stays dry and that the snow will again be nice and corned up during the afternoon.

The Big Challenge
The folks at MRG certainly would like to keep the operation going through Easter and the big challenge here will be to survive some serious adversity between Monday April 2nd and Wednesday April 4th. To put it bluntly, this is a lousy stretch of weather where temperatures and dewpoints will remain above freezing during two seperate periods of rain. No doubt it will do some damage to the remaining base. The first period of rain arrives Sunday night. I would expect about a third of an inch with this first batch and then most of Monday is drizzly or just cloudy and damp. After a dry and mild day Tuesday, another potentially more signifcant period of rain arrives Tuesday night into Wednesday. Both major medium range computer models show this to be a rather dicey predicament for us, one which we will hope to at least partially weasel our way out of between now and then. I know you warm weather lovers may be ready to sign off on winter but the pattern looks to take us on another twist into Easter and I would rather not have this twist preceded by a wash-out.

The Easter Freeze ?
By Thursday of next week, the weather will again undergo a dramatic shift. One, which according to all indications, will send us right back into the grips of old man winter (A nice gentlemen who I have tried to befriend over the years in hopes of earning favors). The turn to colder weather, especially in the midst of the more unstable month of April, has a very good chance of bringing significant terrain induced or even synoptic (weather system induced) snow. Thus is the reason for my dismay over the rain early next week since it would be nice if the current base would remain in tact for the cold weather since I expect this cold to remain with us through the holiday weekend.

Wednesday, March 21, 2007

Weekend appears mainly dry and sub-freezing only in the early mornings

The warm weather is arriving on schedule but it is not in the format I would have specified. If it decides to warm I was hoping for 50's and at least a couple dry days before any rain. Instead, following some freezing rain/rain and a few hours of sun and mild weather on Thursday, more rain will move in courtesy of fast moving front Thursday night. We will get some wind ahead of the front accompanying both the mild weather/rain and this combined with the high dewpoints will do some damage to the base by the time it dries out Friday. Fortunately, the game shoudn't be over regarding the weekend, a period of time which is expected to be mostly dry. Saturday will feature morning temps below freezing but the snow should quickly respond to above freezing temps before noon. Sunday appears a bit more overcast but again, mostly above freezing and with only a very slight chance for some light rain.

This is one of the last updates of the year since it is entirely no fun to forecast when it will rain and when it will not. First of all, the next 10 days will all feature temperatures which are mostly above freezing during the day since the pattern fundamentals appear very warm. Monday appears dry followed by a chance for showers on Tuesday. Wednesday appears dry and somewhat seasonable but then very mild weather is indicated to precede a potentially more significant period of rain toward the end of the week/month. I would expect at least one extremely mild day ahead of the rain late next week either next Thursday or Friday.

A positive AO combined with an energetic pattern in the northeast Pacific Ocean is driving the pattern over the next 10 days. By the first of April the overall picture appears changed and the sustained above normal temperatures may come to an end. April is a month often full very convaluted jet stream forces which form circumstantially but often are difficult to displace once in place. It is often referred to by weather enthusiasts as "cut-off" season where large and anomalously cool/warm pockets of air at jet stream level are removed from the main jet stream current and provide extended periods of rain, snow, dry weather or mild weather. 1997 we struck it rich and had a spring full of well-positioned "cut-off " lows at jet stream level which meant an unusually high amount of spring snow. I don't recall how late Mad River Glen remained open in the '96-'97 season but it was an epic season at Tuckerman's ravine when if I remember correctly, skiers were riding John Shurbourne to Pinkham Notch well into May.

http://www.uvm.edu/~empact/data/gendateplot.php3?table=SummitStation&title=Mount+Mansfield+Summit+Station&xskip=7&xparam=Date&yparam=Depth&year%5B%5D=1996&width=800&height=600&smooth=0&csv=0&totals=0

1997 featured a period of warm weather early in March before the pattern reverted back to cold. It would not be surprising to see 10 days of mild weather to finish the month of March here and then more cold weather. It may not be enough to keep MRG open well into April but it would be wise to keep the ski's and the winter weather gear handy.

Thursday, March 15, 2007

Hitting another one out of the park - 16" to 24" of the white stuff for Mr. Shamrock

I don't want to hear any complaints about how the snow is better over some different section of the northeast. MRG is poised to "sweetspot" another big noreaster. And it is no misprint, there will be no place better than the northern half of Vermont and no ski area better to enjoy the big powder than MRG. And no better time since very warm weather continues to loom toward the end of next week and persisting through the rest of the month of March.

The St Paddy's Day Storm of '07

North winds have brought the cold back into the region as of Thursday night and put the mud on temporary leave I am happy to say. Of equal importance was the injection of dry air into the region and single digit dewpoints. This helps to lower the wet bulb temperature which means a lower temperature when the snow is falling which means powder as opposed to wet glop. That powder will begin falling and begin accumulating at 1-2 inches per hour Friday evening. As mentioned a few times the storm evolves as the amplification of a strong eastern upper trough re-energizes the cold front which already has passed us by as of late Thursday. As this storm really begins to get juiced on the Mid-Atlantic coast the dynamics aloft will provide a healthy negatively tilted diffluent area over New England. To put it plainly the aforementioned is a mechanism which throws the deep moisture back into the cold conveyor of the storm. Many times over the past few years it is this very feature which is lacking and thus the moisture and snow get confined to coastal areas. Anyways the track of the storm barring a change will be west of the city of Boston. This will most certainly bring a change to fain for Beantown but will also push the snow/sleet line into Vermont along a southwest to northeast running line. I think our worries over this are minimal. The 1-2 inch an hour snow will become 3-4 inch an hour snow in the pre-dawn hours and by the time the sleet lines nears, our 16-plus inches of snow will have already fallen, the lifts will begin to churn if all goes well.

Any wind hold Saturday ??
The storm will bring with it the classic northeast wind Friday night which will become north Saturday morning. Winds will be rather feisty but I gave this some study after the wind hold situation on March 2nd and discovered that the strength of the low level jet over Vermont in the March 2nd event was incredibly strong and thus produced the threshold winds at the summit. The low level jet is not as strong in this case so my guess is no wind hold but check www.madriverglen.com for any updates. Wind holds are difficult to predict and occur many times because of wind direction rather than speed.

More snow Sunday more snow Monday night
Terrain induced snow stemming from the powerful upper air support associated with the storm will begin Saturday night and mean additional snowfall both before and during the day Sunday. The snowfall Friday night will be of the high density variety, the snow Sunday will be all fluff and very low density and may persist through the evening before tapering off. We could easily do another 4-8" out of this before it subsides A fast moving clipper then brings a round of light snow Monday night before the last round of colder temperatures pushes in late Tuesday into Wednesday.

How warm in the long range ?
And then its the warmth which will come fast and intense and corn up all of the snow by the end of the week. This is not above-freezing warmth either this is potentially 65-degree warmth by Friday the 23rd. Assuming we keep the rain away, some big time spring conditions can be had. There will be oscillations in the intensity of the mild weather but it will persist for a time and seriously eat at the base before the month is out. Nothing unusual for late March but the pattern fundamentals appear especially warm in this case presenting the possibility of another 1998-like late March situation.

Wednesday, March 14, 2007

Big time powder looking more like reality for St Paddy's Day !!!

The winter comeback is real and talk of a storm for Saturday will pick up some big time steam if it hasn't already on Thursday. Following some rain, colder weather will slowly build back into the region, just enough in fact to set the stage for another major dump of snow beginining Friday evening and persisting through early Saturday. The culprit is the re-energized front which will evolve into major east coast storm by Saturday morning sending moisture deep into interior New England. Models are not entirely certain on the track of the storm but the consensus of information has the deep moisture reaching much of the North Country. The challenge now shifts to keeping all levels of the atmosphere at sub-freezing thus preventing snow from changing to some sortve unwanted alternative. An update will be needed to fine tune whether or not this will happen and to close the range on expected snowfall. As of now I would put this range at a generous 8-24 inches, enough to qualify this as the St Paddy's day storm of 2007.

Tuesday, March 13, 2007

Winter makes a comeback this weekend but strong indications of warmth perist late this month

The general theme from the last post was "changeable" and while we continue to see a change in the weather at least the theme of the SCWB posts remain unchanged. I continue to give my blessing to Wednesday in spite of what NWS Burlington is suggesting. Heck, why not have a little fun with the short term forecast late in the game. NWS Burlington is calling for showers in the morning Wednesday and then rain in the afternoon with the chance of precipitation at 80 percent. I think most of the rain stays away from MRG during the ski day Wedneday or at least through 3 pm. Instead I think we see a few hours of blue skies to go along with the very mild weather where temps at the base will reach or exceed 50 degrees. We will just have to see what happens but my reasoning behind forecast can be attributed to the nature of this weather system. Most of the vertical motion tomorrow will be frontogenetic and the system tomorrow will become anafrontal. This means that precipitation tomorrow will fall north of the cold front or north of MRG, at least until late in the day.

Winter makes a 5-day comeback after some rain Thursday
As the cold front sags south Thursday the doors will be open for rain which should fall mostly during the morning hours. Drier and colder air will then push south and assume the drivers seat position. Although it will not stay dry the cold weather will remain in place through the middle of next week which opens the door for a resurgence in more winter-like conditions on the mountain. The first chance for snow comes late Friday or early Saturday as the front (now well to the south) is re-energized and an east coast system of a somewhat uncertain nature comes to life. The possibility range is still a bit wide here and if we fail to entrain enough cold air into the region on Friday we could be looking at a cold rain or ice. The more optimistic outcome has snow either late Friday or Saturday and at least a few inches of powder for Saturday. Following a cold and somewhat blustery Sunday, a clipper system approaches for Monday bringing another chance of both synoptic and later terrain induced snow. The cold is then re-enforced very significantly with much below normal temperatures Tuesday or Wednesday.

Long range has a very warm appearance
The long range outlook has changed little since the last update and the already proposed ideas can be amplified further based on the continuing stream of incoming data. Unseasonable warmth of a rather incredible magnitude is the indication for the period beginning late next week and lasting through next weekend. Many of these ideas could change significantly but a fair translation would be for few days where temperatures exceed 60 degrees and a lot of melt. Not unusual I suppose to see anomalous weather in March and such may be the case beginning late next week on the warm side.

The Quick Summary
SCWB fights NWS Burlington for mainly dry weather through 3 pm Wednesday. Winter makes a return for the weekend through the middle of next week and then it could get very, very warm.

Sunday, March 11, 2007

Changeable March weather to continue

With tickets at MRG now discounted to the bargain price of $29 for the duration of the season, the SCWB will also be updated at a discount which essentially means shorter updates and hopefully more to the point (although I'll believe it when I actually see it when it comes to my writing). The cold air has won many formidable battles as of late but mild weather is now in command and plans to remain so for most of the upcoming week. After that, it will be another roller coaster and the models fighting the sibling rivalry regarding the details. I am happy to report however that my take on the situation involves a high probability for one powder day next weekend.

Short term through Wednesday
Temperatures Monday and Tuesday will be sub-freezing in the morning and then warm into the 30's and 40's during the afternoon. Monday will be the sunnier but likely colder of the two with below freezing temperatures persisting longer into the day. There is a chance for a shower during the day Tuesday although whatever falls from the sky should be light. It is Wednesday which appears extremely mild and it is my opinion that afternoon temperatures surge to 50 and perhaps beyond before the day is out. The American Model disagrees with this notion suggesting a cloudier day Wednesday, not as warm, and perhaps some rain overspreading the region late in the day. I am going with the warmer hot off the presses European which would suggest a breezy but dynamite spring skiing type of day if your a fan of the corned-up softness.

Late this week and the weekend
The models have made a mess of themselves for late this week. There is no agreement what so ever regarding the details between Thursday and Saturday. In general however we do have a sense of the progression. At some point either Thursday or Friday we are going to get a healthy period of rain which for a time could become heavy I am sorry to report. I'll have to figure out the details in a subsequent update. As this is happening however a large upper level ridge is expected to build across the western United States which will allow much colder temperatures, which continue to persist across much of northern Canada to dive south into the eastern United States. The cold will invade as early as Friday and the rain may become a significant period of synoptic or terrain induced snow either late Friday or early Saturday. So, in spite of the mild weather and the rain this week, colder weather will return for the upcoming weekend and in all likelihood so will accumulating snow. Hopefully enough to cover any bare spots or ice which may develop.

More mild weather in the longer range
The ridge west/trough east scenario will continue through the first half of next week and in that time frame the colder, below average temperatures will continue to prevail. In addition there appears to be another chance for a snow producing storm between Monday and Wednesday. Wednesday of next week is the spring equinox and also marks the day where both the European and American Ensemble packages start to show an extremely big warm signal for much of the eastern United States including New England. It seems a bit rediculous to talk about agreement in the 11-15 day period when there is little in the first 5-days but the AO is shown to go very positive in this period so all signs point to a warm-up and a potential thaw after the 21st.

The Quick Summary
Warm to cold and then back to warm. New snow appears likely in the cold period beginning late Friday of this week and ending during the middle of next week.

Thursday, March 8, 2007

Riding the March roller coaster: Record cold Friday morning and then a thaw next week

The SCWB is getting a little dusty and an update is greatly needed. The month of March never ceases to amaze me. Statistically, it is one the noisiest months of the year in New England where temperatures have fallen to -25 F and have risen to as high as 70 F. The recent outbreak of cold has been historic, shattering records all across the state of Vermont by several degrees and even approaching historical lows for March in some instances. Several more records will get broken Friday morning as temperatures, once again fall to -20 F in some areas before warming into the 20's Friday afternoon. There is no need for the cold wax this weekend however. The temperature moderation Friday afternoon will be the beginning of a more signifcant trend, eventually evolving into our first real thaw of 2007. I suppose I should re-state since its our first real thaw since those disastrous first two weeks of January.

The Telefest Details
The weekend as it turns out, although significantly milder than the recent days, will not be as mild as once was expected (like my last update). Temperatures will start out in the teens and quickly rise to freezing and even a few beyond by the early afternoon. The high sun angle and the warmer temperatures will be enough to soften the snow, particularly at the low elevations but we should see an increase in clouds and eventually a full overcast by the middle of the afternoon. The precpitation which should arrive late in the day on Saturday is not likely to be snow but either rain, freezing rain, ice pellots or sleet depending on the excact location. It should be a rather short-lived round of precipitation, whatever falls, which will end as a bit of snow or flurries. Sunday appears mostly dry with temperatures in the 20's at the beginning of the day and 30's during the afternoon.

Signs of spring next week
The Arctic Oscillation index (AO) will surge to a big +2 next week and the Jet Stream will respond by tightening and becoming both very fast and very zonal. In addition to this is the trough which is expected to re-amplify across Western Canada. This would be a very sinister conspiracy if it were mid-winter but our big base should combine well with the warmer weather to make for some nice skiing. And I can say with growing confidence that it will get warm. NWS Burlington is saying low 40's which covers mainly the valley locations for Tuesday and Wednesday. At the MRG base, I would not at all be surprised to see temperatures climb into the 50's during the afternoon on at least two occasions between Tuesday and Friday. The best news with the warm weather involves the precipitation which will be minimal through Thursday. On Friday, a well organized storm system, fueled by a strengthing trough in the middle of the country may bring significant rain to the region followed by colder weather for the weekend of the 17th and 18th but its difficult to say for sure. If we do get rain accompanied by wind late next week, it will eat away at the base significantly but again, this hypothetical storm may never materialize or evolve differently relative to current model guidance.

Some cold/snow returns by next weekend
Ensembles erode the big trough in B.C./Alberta by the 17th and 18th and suggest that a large ridge develops across the western United States. The AO's big surge next week is also expected to be temporary in nature and a move back to neutral combined with the manifestation of the western ridge will allow for a return to colder weather and some new snow to go along with that after the 17th. All that being said, there is no strong signal for any sustained pattern of an anomalous nature. If colder and snow were to return on or just after the 18th, it may again be followed by another round of milder weather.

The Quick Summary
Record cold Friday morning but then some big changes and a thaw next week.

Sunday, March 4, 2007

Cold weather, new snow will keep our big base intact for a mild Telemark Festival

The last few days has been MRG at its very best. Conditions that are worth hiking up the mountain for when the Single Chair goes on a wind hold and enough snow to cover some normally very visible landmines. As of Sunday morning, the terrain induced snow machine has kicked into gear and the fluff is starting to accumulate. With high confidence, I can say that if you want to enjoy the powder, get out here over the next 5 days which promises to be a very wintry and surprisingly very cold week for early March. All of the recently fallen and soon to be fallen snow will remain on the ground for the all important Telemark Festival on the 10th and 11th but the mild weather will arrive and most likely so will the rain which has managed to avoid MRG for an amazing 55 days by my count.

Mountain fluff through Tuesday morning when it will turn very frigid
That oragraphic fluff that can so magically turn us into better skiers will accumulate nicely Sunday and Sunday evening and should set up Monday well for another powder day. Total accumulations by Monday morning may very well climb into the 4-8 range although some of this snow will be skied during the day Sunday. There is a very potent jet impulse however which will rocket southeastward out of central Canada Monday and bring with it another burst of heavy snow late Monday and Monday night. This will mean more terrain induced powder but also some windy and extremely cold conditions for early March by Tuesday. I just looked at a plot of temperatures for North America and there is an impressive arrangement of -40 to -50 degree temperatures across the Northwest Territories of Canada and the airmass poised to invade us Tuesday will bring with it some of this frigidness. High temperatures Tuesday will struggle to make it above zero on the mountain and temperatures Tuesday night and Wednesday may fall into the record category atop the deep snowcover Wednesday morning. The March sunshine can help to mitigate the effects of the chill a little since it isn't always hidden behind Stark Mountain but I didn't want to downplay this cold because its one of the more impressive invasions of arctic air I have seen in March. Furthermore, a clipper system which will pass to our south Wednesday will act to re-enforce the cold through Thursday before temperatures finally moderate significantly Friday. I recall Thursday that I had prognosticated 2-3 feet over a 5-day period beginning last Friday. We are at about a foot now and we can easily do another between Sunday and Tuesday morning thus putting us in my predicted range. I am happy to report however that very little if any of our impressive base will be lost for the upcoming Telemark Festival.

Telemark Festival Details
The Telefest details are as follows. Friday will see some cold temperatures in the morning but any sunshine will go to work and we will undergo the routine March afternoon snow softening. Now Friday could feature more clouds than I am giving it credit for which would limit the afternoon warmth. Warm advection is often accompanied by high cloudiness although at this time models are suggesting a good deal of sun for Friday. At this time models are also showing the potential for a very mild day Saturday with the possibility of some rain late in the day. With our base though, corn snow and spring conditions will be just fine so long as we can stay out of the rain and we may do that for most of the ski day although its early, very early to be specific. Some colder weather will then return on Sunday, hopefully accompanied by snow showers although my glass appears half empty on that possibility at least now. A full update on Telefest weekend will come Tuesday or Wednesday of this week.

The big March picture
It has been storminess central for Alaska, British Columbia and Alberta over the last few days and over the upcoming weeks. This has resulted from pattern consisting of a large trough over which has oscillated between the northeast Pacific Ocean and the western provinces of Canada. This is undoubtedly a less than desirable force ski weather here in Vermont but we have held it together impressively thanks blocking in the jet stream which has oscillated between northern Quebec and Greenland. The all important AO has been running close to neutral but has refused to go strongly positive, thank you, and is expected to remain neutral over the next week or so before re-assuming its negative state by the middle of the month. This would suggest that winter is unlikely to vanish rapidly into the night. Ensembles suggest that between the 9th and 14th of March, we could see some very mild days and perhaps some rain to go along with it. By the middle of the month however we could be back to seeing a mixture of mild March days and an occasional powder day.

The Quick Summary
Full of powder through Tuesday but very cold, even record breaking cold is set to set to invade for the middle of the week. Our luscious base remains in place for Telefest when it gets mild and hopefully does not rain while the lifts are open.

Thursday, March 1, 2007

Storm Update - New data shows a colder storm

I keep looking at the data as it comes in and with each successive run of the models, cross sections for northern and central Vermont appear colder. The last run of the high resolution model did not show an above freezing layer at MRG which would mean all precipitation Friday would be snow. What may end up happening is that instead of a significant amount of sleet Friday afternoon, a dry slot will move across the region which would mean a cloudy but mostly dry Friday afternoon after the heavy snow in the morning. In either case, we are getting our 6-10 by mid morning Friday and it will make for a great day.

Could we do 2-3 feet over the next 5 days - absolutely yes !!!
The better part of this situation continues to be the set-up in the aftermath of Friday. We have Friday evening where another round of snow will likely bring a few inches to the mountain. On Saturday however the dyanmics arrive and the terrain snow machine will kick into high gear. There will be undulations in the intensity of the snow and it will be hard to predict specific amounts each day. One period where the snow might become intense is Saturday afternoon and evening. Most importantly though is that the snow should continue in sporadic but at times intense fashion in the period beginning Saturday and ending Tuesday. When you the Saturday-Tuesday amounts with Friday's amounts 2-3 feet is a very reasonable guess. Be aware however that valley locations will see snow mainly on Friday and the limited sunshine on Saturday, Sunday and Monday could send temperatures in the Champlain Valley to near 40. It will be a lot different though in the high country and a lot better for skiing.

Wednesday, February 28, 2007

Lots of fresh powder for Friday morning then a little sleet

The Valentines Day Blizzard was the strongest winter storm to impact the region this season without question but the runner-up may be the upcoming March 2nd to 5th event. This is an entirely different beast but the news with this system is mostly positive since above all, its effects will be felt beginning Friday and persist into Monday or perhaps even Tuesday of next week. This is the second in a succession of huge winter storms for the Upper Midwest, an area which has been snow starved most of this decade. Usually, systems which strike the Midwest hard with snow bring a combination of snow and ice to Vermont and New Hampshire and the forecast challenge becomes predicting all of the precipitation types, amounts and the timing of all precipitation changes.

Storm details - 6-10 inches of powder for first tracks Friday
As the storm continues toward the eastern Great Lakes and brings a push of warmer temperatures with it, a second low pressure area will form near Long Island and re-concentrate the heaviest precipitation over Northern New England. More importantly, this second low will prevent some of the warmer temperatures from invading MRG and changing precipitation to freezing rain and rain. So here are the specifics as best as I can see. Snow will develop at MRG within a few hours of midnight Friday and quickly become moderate to heavy in the pre-dawn hours. Based on some of the latest higher resolution model data, a quick 6-10 inches of powder is likely by the time the single chair begins churning Friday morning at 9 am. This of course means some dynamite runs early in the day. Cross section profiles however show above freezing temperatures overspreading the region during the morning which would quickly change precipitation to sleet which is then indicated to continue through the duration of the ski day. Sleet although less than ideal is not terrible to ski in but can feel like needles driving in to your skin while skiing at higher speeds. Freezing rain may be less painful on your skin but I would hate to see a one inch glaze of ice atop the 3-6 feet of snow currently on the ground at MRG. This deplorable situation will be mostly avoided in northern Vermont since the above freezing layer is above 8,000 feet with well below freezing temperatures remaining in place below this layer. All in all, I think skiers will be happy with Friday's results. The heaviest precipitation is indicated to fall as snow and the icy precipitation is shown to fall as mostly sleet. Total accumulations snow/sleet by Friday evening will range between 8-14 inches. And by the way, precipitation goes back to snow Friday evening and may add a few additional inches to this total by Saturday morning.

Terrain induced snow for the weekend
What I am especially excited about is the set-up in the aftermath of Friday's precipitation. The upper low which is closely associated with the original Midwest winter storm will push slowly toward and through the region during the weekend and early next week. As a result, low level instability will increase and set the stage for a long duration terrain induced snow situation. Winds will be west-southwesterly and it will not be especially cold over the weekend. It may very well turn out to be one of those early spring situations where sunshine and near 35 degree daytime temperatures prevails in the valley locations while snow showers in the mountain locations are occasionally producing heavy snow. The highest snow totals strictly from the terrain induced snow are most likely to fall in the north but the additional snow between Saturday and Monday could very well exceed a foot at MRG and this would include significant amounts of fresh snow at first tracks time both Sunday and Monday.

Rest of next week/Telefest weekend
The terrain induced snow could very well persist through Monday Night into Tuesday since at this time a reinforcing shot of colder weather is expected to make a push into the northeast. Dry and cold weather will temporarily prevail for a time during the middle of the week before another system takes aim at the region, again threatening to bring a signficant push of warmer temperatures with it. We have stiffened our differences on two different occasions and will avoid rain in both instances but in this case (late next week) we are in hot water. The upper trough in the western provinces of Canada has been a persistent negative driver and with each passing system we are risking a bad outcome. The days leading up to telefest weekend are appear especially troublesome since both ensembles show a strong signature for zonal flow with the anomalous warmth centered over the northeast. Sorry to be the bearer of bad news but we may be forced hope to minimize the damage. Such a task is feasible if the warm weather is accompanied by sunshine and minimal rain and the jury on that is still out.

Is this it for winter ?
Actually, I think winter still has something left. I am still watching the Arctic Oscillation carefully and although it is forecast to go positive briefly it may not remain as such. For much of the country this may not mean much but I do think the weather remains interchangeable or more specifically, I don't think that any warm weather late next week or on Telefest weekend is permanent across the North Country. Unfortunately the pattern looks something short of sustained cold and snowy which simply means that after March 8th, we may have to look individually for the warm and sunny or occasionally snowy days. Remember the healthy MRG base when combined with the warm weather is a nice and welcomed combination late in the season.

Monday, February 26, 2007

Some good news to report for early March

The update for the March 2nd to March 5th period is a positive (mostly) one I am happy to report. This will be the second in a succession of juicy systems to exit the Rockies in a 5-day period. Model guidance has hinted in both cases that warmer air in the troposphere's middle layers will change precipitation to the dreaded icy mixture, particularly freezing rain. In the first case, the system weakened and passed way to the south and we will be lucky if we squeeze out a few terrain induced inches Tuesday and Wednesday. I will take dry weather over ice any day however and we have now successfully kept the rain and ice away from MRG for 41 consecutive days dating back to the MLK day where snow changed to sleet and freezing rain for a few hours before ending. This next system is also poised to trigger a huge northward push of mid-level warmth into the region Friday threatening to end the streak. The situation however looks far better than it did a few days ago.

March 2nd - 5th details
Like its predecessor as this storm pushes east through the Midwest, a second low pressure area will try and intensify very quickly off the Atlantic Coast and act to thwart some of mid-level warming across interior New England. In this case the task will prove to be a bit more difficult unfortunately since this system will track farther north effectively bringing both the moisture and some of the warmer temperatures at the surface and aloft to Stark Mountain and MRG. It is a very close call at this time and the outcome could go either way. At this time it looks as if precipitation would develop Thursday Night into Friday morning as snow then change to a mixture of mostly sleet and perhaps some freezing rain. The American Model would suggest a better outcome with more snow and less ice out of this initial batch of precipitation. The European however has taken the American to the cleaners all winter in the 3-5 day period and is suggesting a warmer less snow more ice outcome out of Friday's precipitation. I am not sure what to think about the disagreement, I know its a critical one but we will have to iron out these differences on Wednesday with a subsequent update. There is some good news in that even the worst case scenario does not include a lot of freezing rain. The real good news is that some of the good dynamics associated with this fairly intense system will settle near the region during the weekend and for a good part of the first full week in March. This could very well mean some hefty terrain induce snow amounts beginning on Saturday and persisting through Tuesday March 6th. In summary, whether sleet/freezing rain falls at MRG or no on Friday, the next week appears very promising as far as skiing goes.

Nothing new in the longer range
I have nothing new to report as far as the longer range is concerned. Indications are that much of the country will see spring-like temperatures in a week to ten days. Across interior New England, it will be a mix of warmer than average and colder than average temperatures.

Friday, February 23, 2007

February to end without one drop of rain or ice, March is up for grabs

No ice or rain early next week but although one battle appears won another will need to be fought between the 2nd and 4th of March. As I mentioned in previous posts, we already have one unfavorable force driving the weather pattern which is the general troughing across western North America or the negative PNA, but by early March more teleconnection indicators will turn against us and may have us on our heals by the first full week of the month. I am not at all calling the situation dire as we may yet find ways to fend off most of the trouble through even March 10th, but ominous it remains.

A mainly dry weekend
The airmass this weekend will keep temperatures below freezing, but it is a very stable one. As a result, terrain enhanced snow will be kept to a minimum Friday Night and Saturday and any clouds Sunday will of the high variety and non-snowfall producing. The high winds Friday will diminish somewhat by Saturday and completely by Sunday. Temperatures meanwhile will climb close to 20 Saturday and well into the 20's by Sunday.

Early next week
The situation for early next week has now come full circle. Downstream blocking in the jet stream is now going to suppress much of the moisture from the storm which, not more than a few days ago, was predicted by many models to produce ice and even rain for MRG. This storm is a strong one as it moves out of the Rockies today but the system will mature too quickly and begin to lose steam as it advances into the Ohio Valley. A second low is expected along the Atlantic Coast and spread precipitation into New Jersey or southern New England Sunday night or Monday but this moisture is not expected to make its way farther north. Eventually as the storms original upper level support moves into the northeast, chances for snowfall increase, particularly in the high country. If this occurs, it will not do so until late Monday or Tuesday and we will have to hope that some lingering moisture is there to be had. The chances for any new snow from this "upper level support" continue into Wednesday before high pressure dries it out.

The move into March
I have gotten a lot of emails about early March and for good reason. Typically it is a great time to ski MRG since the base usually peaks in the first two weeks of the month. Using the Mt. Mansfield snow stick as a reference, we look to be in fairly good shape going into March 2007 (above normal base) but things can turn in either direction in a big hurry depending on whatever weather decides to prevail. The events of March 2nd to 4th appear to be one very important "up for grabs" situation. If you type the Waitsfield (05673) zipcode into weather.com you will get a 10 day forecast which advertises rain/snow showers for Friday the 2nd and plain rain showers for Saturday the March 3rd which hardly does justice to the scope of the event. Weather.com 10-day forecasts are derived from The Weather Channel extended maps which are in turn derived from a computer algorithm which takes actual model data and spits out 2-4 word weather answer for the day. It's an impressive process actually that a good friend of mine from college helped to develop and continue to develop. One of the reasons for the blog was to help us skiing enthusiasts dig a little deeper for answers since 2-4 word answers rarely give us the detail we would like to see or an accurate possibility range. The storm late next week could actually turn out to be an intense one and at this time models are suggesting it tracks anywhere between the St Lawrence Valley (ugh !) and the southern New England Coast (better !). The St. Lawrence Valley track would mean ice, perhaps even rain while a track farther south could produce signficant amounts of new snow. The downstream blocking which played a key role in shunting the Monday-Tuesday event southward will shift west and take-up most of the northern Province of Quebec by this time (The NAO is therefore expected to turn slightly positive). I am hoping, even praying that the storm will simply undercut the blocking in Quebec and therefore turn into the snow producer we would all love it to become. I actually do think this occurs to some degree but can't rule out a period of icy precipitation Friday or Saturday as our worst case. Even this worst case would mean a turn to accumulating snow during the weekend.

General thoughts on the pattern in early March
After watching the ensemble data over the last few days I have decided that much of the country will see mild, spring-like above normal temperaures for the first full week in March (March 4th -11th). The exception to this will be the Rockies where a trough will amplify bringing snow to many ski areas there and northern New England which will sit on the southern fringe of colder weather which is expected to remain across Canada. I say this because there are high lattitude blocking mechanisms but barring a change, will be positioned in all of the wrong areas for below normal Eastern U.S. temperatures which goes along with the teleconnection indicators which will be generally unfavorable. The ensembles, warm as they may be for areas of the central and eastern U.S. south of 40 degrees north are not especially warm north of this line and are actually cold north of 50 north lattitude. I therefore think the outcome will be a battle between warm and cold over the northeast and this usually means weather of many varieties over the span of a week. More clarification on this will come next week.

The Quick Summary
One ice storm is avoided early next week, but another close call looms for the period March 2nd -4th as the weather pattern has clearly moved away from the completely favorable mode.