Wednesday, January 28, 2009

Storm is delivering, not much else to say except 10-20 remains a good range

and the this range would increase except I am a bit concerned that the mid level center of this storm will pass relatively close to the mountain. Snow will continue to fall at very good rate through the rest of the day Wednesday into Wednesday evening with accumulations close to the bottom of our range. The proximity of the mid level center of this storm can also mean that we can get impacted by a dry slot as the storms moist conveyor gets pushed too far to the north. This may happen briefly late this evening before snow returns to MRG for several of the AM hours Thursday.

The energy and moisture with the weekend system will remain off the Atlantic coast. There is a weak disturbance which will help solidify the upper trough in the east and this will leave a window of "terrain-induced opportunity" early Saturday. That was flowery but it translates to a light accumulation of snow early Saturday along with some chilly temperatures. Readings this weekend will be a few degrees below zero in the morning and rise into the teens Saturday and 20's Sunday.

Models are having a bit of fun with a system early next week. It will be milder by then and the possibilities are very wide ranging and they do include ice and rain and one end and all snow on the other.

Have fun with the snow and I will try to give a more in depth update on Friday.

Monday, January 26, 2009

Wednesday storm looks stronger, and farther north and this means MRG is ground zero for big time powder !!!

It is yet another twist of fate in the world of weather that draws comparisons to Valentine's day of 2007 but not on as grand of a scale I am sorry to say. Still it is very significant and this storm now appears as if it will be one of the bigger events of the season to date and will turn Wednesday and Thursday into two of the more memorable days on the mountain.

So what is happening ? Our Wednesday storm is just beginning to draw moisture from the juicy Gulf of Mexico as I write and although the upper level support for this storm will be lacking for a while, it will phase with northern stream energy a bit more efficiently verses some of the indications from a few days ago. By the time it reaches the Atlantic coast it evolve into a storm that is slightly better than simply garden variety. Another important development is the track of this storm. Just days ago, a few of the medium range models showed our Wednesday storm to be a total miss for interior New England but the phasing that I mentioned above often means a northward turn and it also means a broader moist conveyor and precipitation shield. The result, to put it as plain as day, Mad River Glen will be one of the best locations for snow from this event and those words go down as easy as one of those fancy expresso drinks on a bitterly cold day.

10-20 inches and some additional details
In terms of timing, the storm will advance through Tennessee late in the day Tuesday and spread precipitation into Vermont between 2 and 7 am Wednesday. Snow will intensify as the morning continues and fall at an occasionally heavy rate into the evening as the storm intensifies as it approaches Boston, making use of the natural baroclincity that the Atlantic Ocean provides. The snow should continue into early Thursday morning before tapering to flurries and snow showers. All told, we can conservatively expect 10-20 inches from this event with fresh powder on Wednesday and Thursday. Weaker disturbances Friday and Saturday bring the possibility of some additional lighter accumulations but take advantage of that mid-week MRG rate if you can because 39 bucks on a powder day at MRG is steal even in this economy.

Saturday, January 24, 2009

"Active Pattern" appears somewhat less active but new snow should still be expected

We have hit a dry spell in terms of our natural snowfall. We have been in the midst of a chilly regime and this regime has allowed us to avoid the rain and ice for much of the month. According to the observations at the Montpelier-Barre airport, only 0.90 of liquid has fallen if you melt all the snow and sleet. Mad River's elevation has ensured that precipitation amounts have been a bit healthier on the mountain but still well below average. Although we do have some snow to talk about for the upcoming week it will not be enough to dilute the cold and dry personality that January 2009 has now attained.


Along with the cold, we should, with the help of some low level instability and a quickly moving disturbance, pick up a little snow Sunday night into Monday in the form of snow showers and flurries. It will not amount of much and it will precede a very cold and calm night Monday night and a calm and somewhat sunny day Tuesday. The storm we have been watching for a while on the forecast charts will be making its way across the country Tuesday. This is a much weaker storm than I was hoping for, mainly because it lacks the upper level potency necessary to generate any real excitement. It will be close enough to the Gulf to draw in some moisture but it will remain a "positively-tilted-frontrunner" which is another word for garden variety. The other problem is the track which appears to put us somewhat out of this storms main path. We should still get some snow out of this either Tuesday night or Wednesday but the actual amount will depend what part of the 100 mile north-south possibility range the storm takes aim at.

Late this upcoming week and the weekend
This initial storm system Tuesday night and Wednesday will mark the beginning of a brief period when the upper trough is situated in eastern North America as opposed to the west (the prevailing pattern). I was hoping the period might be a bit more fruitful since if you add some incoming Pacific energy into this situation one can cook up an east coast storm rather easily. This in fact may well happen as lingering moisture in the Virginia Tidewater combines with energy from a "Saskatchewan Screamer" around Jan 30 or Jan 31. The problem is, all this cooking looks to be too far east. The SCWB will be watching this one as the week progresses but the chances are a bit on the low side right now and my guess is for a period of snow showers Friday into the the early part of the weekend and a light accumulation. It will continue to be cold but not extreme with morning temperatures a few below zero fahrenheit and within a few degrees of 20 during the afternoon. On Sunday Feb 1, another clipper will be passing through the St Lawrence Valley. This system may mark a temperature moderation to follow and it may bring a few inches of snow although nothing noteworthy.

Mild and dry at the beginning of Feb ??
The biggest upper level feature in the western hemisphere (north of the equator) will eventually be a large block over Greenland which as I mentioned in a previous post will help to counterbalance the western trough and more active Pacific Jet. This block will migrate southwestward somewhat into the Davis straits and creep into interior New England. I remember a pattern like this around the time of the Super Bowl in 2005. It eventually evolved into a good pattern by the middle of February but this block, if it gets too close, can bring a round of mild temperatures to the region. Since we are talking about a block however, the risk of rain and ice remains relatively low however and its merely just mild and dry. Weather systems in such a pattern are often forced well under the block and become cut-off somewhere along the eastern seaboard. If these storms move far enough north it can mean snow for the mountains but I think this would be wishful thinking right now. The Feb 1-Feb 8 period may be safe from a big rain thanks to the block and negative NAO but my guess is that it turns out mainly dry with some above freezing days and below freezing nights (sounds a bit like March but we will see)

Tuesday, January 20, 2009

Storm track for Saturday shifts north, active pattern starts January 25

The base at Mad River Glen has made a slow but steady recovery since the great post Christmas thaw. If we use the Mt Mansfield snow stick as a reference then our base is slightly above average. The base has been aided by temperatures that are running almost 5 degrees below average for the month of January and with more cold on the way late this weekend many areas of New England will see the coldest month of the decade after seeing some of the coldest temps of the decade just days ago.

Northward shift in Saturday's storm track lowers snowfall expectations

Snowfall for the balance of the "work" week will be held to a minimum. Flurries and a few snow showers can be expected across the northern half of Vermont on Thursday thanks to a disturbance that I should forget to mention. Temps, as promised, will climb back into a comfortable territory although I would enjoy this while it lasts because it won't. The system we have been keeping our eye on in the shorter term is a clipper system that will mark the charge of the next round of biting cold. The latest indications are that the best conveyor of moisture will be situated farther north into Quebec. I had hoped would get lucky and get 5-10 inches of low density fluff with this sucker but expectations of now should be appropriately lowered to the 2-4 inch range. Most of this minimal accumulation will fall prior to first tracks time Saturday and when the snow ends we could see temperatures inch toward the freezing mark by early afternoon. During the evening, winds will shift into the northwest and temperatures will fall dramatically and be well below zero with -20 wind chills on Sunday.

Active week Jan 25-31
The week beginning January 25 has lots of promise but the details remain difficult to resolve. We will at this point replace the ridge in the interior west with a trough. This can be quite detrimental and can cause a thaw or a round of rain even as far north as interior New England. As the ridge is developing in the west downstream blocking in Greenland and across the extreme high latitude locations will strengthen. It is a stretch to refer to it as "blocking" but it is enough to counter-balance the impact of the strong western trough and will help us avert disaster in the last days of January. In terms of actual weather, the result of all this will be several west to east moving storm systems capable of picking up Gulf or Atlantic moisture as they progress eastward. We will also see a strong south to north contrast in temperatures and this will mean lots of overrunning and possibly lots of snow for parts of New England. The term "overrunning" and New England have always fit well together in case I haven't mentioned it. My guess right now is for two noteworthy weather systems next week with questions persisting regarding where the best zone of snowfall sets up. Sleet or freezing rain is not out of the question but at this time that possibility remains at the edge of the spectrum.

As we move into the early days of February, the continued presence of the consolidated jet stream in the Pacific and a strong trough across the interior west could be enough to induce an east coast rain or ice event. The weather pattern is exhibiting some similarities to the one in late December which first produced an epic powder fest but then gave way to a thaw. We our however later in the season when surface thermal forces such as the the colder and ice covered Great Lakes provide less of a northward magnetic pull.

Monday, January 19, 2009

Cold retreats for a short time then returns; More active weather starts the last week in January

The cold not only shattered records all across the state of Vermont on Friday but for most locations it was the coldest morning of the decade. It was a very warm decade statistically but an impressive feat nonetheless and for those brave enough to face the elements a few days ago, you have earned your bragging rights. The extreme cold has made a temporary retreat although we do expect a return later in the week.

As of Sunday, Mad River Glen was on the fringe of a developing coastal system impacting much of New England. As it turns out, coastal sections will get most of the snowfall but the lower atmosphere is moist and unstable enough for continuous snow showers and flurries throughout MLK Monday. It may only amount to a light additional accumulation but it should freshen the trails up somewhat and with the relatively moderate temperatures and light winds it should be a solid ski day. The intensity of the east coast trough is such that the Atlantic Coast is a stick of dynamite just ready to ignite and blow and I know we talked about a possible coastal storm on Tuesday. This storm, appears as if it will come into being but will likely be too far off shore for a New England impact of any kind; instead, areas of the eastern Carolinas that rarely receive snow will get a few inches. Mad River will see more in the way of snow flurries Tuesday and into Wednesday but with minimal accumulations. We have a better chance of getting a few inches Thursday when the mountains get into an area of overrunning thanks to the push of milder weather.

We will see the moderating temps this week as promised but this is a very short-lived trend. Lake Erie is now almost completely frozen, there is an unusual amount of ice on Lake Ontario and almost half of Lake Huron is frozen. This makes it all easier for unmodified arctic chill to advance quickly into New England and it will do just that this weekend. The frozen Great Lakes can assist us however since they no longer have the same magnetic pull on developing low pressure systems. Friday will be the day when the first such weather system will test the partially frozen Great Lakes. This system is working with little energy and flying eastward on the wings of the advancing push of arctic cold. I would expect some snow with this on Friday into early Saturday but accumulations will held down by the storms quick eastward progress. The cold weather will hit late in the day Saturday and Sunday could be another where temperatures are in the -20 vicinity in the morning and struggle to zero during the afternoon.

We are in the process of losing the strong western North America Ridge and with it the positive PNA index. The other two teleconnections (AO and NAO) are expected to gradually become slightly favorable even as the PNA turns negative. The result will be a much more active pattern across the U.S. and eventually interior New England and Mad River Glen. We will see a consolidated flow of pacific energy and numerous weather systems crossing the country from west to east. The more active jet will undoubtedly deflect arctic air away from parts of the nation but northern locations such as Vermont have the capability of staying on the chilly side of these systems and the results can often be very fruitful. I am in fact looking for some big things out of the weather between Jan 25 and the first week in February. There is a risk for the rogue storm taking the St Lawrence Valley highway and producing the icy mixture we would like to avoid but I am optimistic and will stay so until i see evidence to the contrary.

And I finally joined the Mad River Glen facebook group as the 557th member. Considering i run a weather blog in honor of the mountain that is somewhat embarrassing but for those who haven't joined go ahead and do so.

Friday, January 16, 2009

MLK weekend snow arrives faster than initially expected

And in addition some late day Friday info is indicating a sizable accumulation. This is our friend the "Manitoba Mauler". It does as I mentioned before have the support of some potent jet energy. It also is expected to draw at least a limited amount of Atlantic Ocean moisture as it approaches and this could greatly the boost the amount of skiable snow for late Sunday into MLK day. Most importantly however is that the snow is actually expected to begin in the early morning hours Sunday with 1 or 2 inches by first tracks time. This turns Sunday into one of the better days of the year to ski because the snow should fall at light but continuous rate throughout the day before falling at various intensities into the night and into MLK day. We should continue to see flurries throughout MLK day but the lower troposphere lacks some the instability for a major upslope event. Overall I would expect 5-10 inches of new snow Sunday and Monday. It will be chilly but not nearly as extreme as recent days as temperatures climb into the teens during the day and with the exception of Saturday morning where temps will be near -15, readings will stay above zero at night.

The Tuesday question
The upper trough along the east coast will become very sharp as I mentioned and is conducive for some explosive "cyclo" or "bomb-o" genesis. Models are having a difficult time with all the different undulations in the jet stream and what may evolve when some of these undulations interact with the relative warmth of the Atlantic Ocean. We do have some agreement regarding Sunday's system but changes are still possible late in the ball game. Models have diverged dramatically regarding a second system with a possible late Monday or Tuesday impact. The recent american model has suggested a big east coast and particularly a New England event by Tuesday other indications suggest a storm well-off shore and a blustery, chilly Tuesday and Wednesday .

Late next week and beyond
We are still anticipating a temperature moderation as next week continues to progress but temperatures should remain below the freezing mark and the threat of any rain or freezing rain has diminished somewhat although not entirely. The moderation is supported by the breakdown of the positive PNA regime which has successfully caused a temporary snow drought for our friends at some of the western ski resorts. This will change by late next week as the pattern turns active there. In the meantime we expect a new area of arctic cold to develop across northern Canada and continue to be a major factor in the weather even with no east coast trough. There is a risk for ice after Jan 25 but I would place my bets on a generally active pattern and a few big snow events similar to the pre-christmas powder-fest.

Wednesday, January 14, 2009

Cold subsides by the end of MLK but snowfall is a question

No blog update for a few days either means that I have been busy or I am sour grapes either because the Giants have just lost to the hated Eagles in the playoffs or I missed a forecast. The latter was a bit frustrating because I had it on these other guys all week by talking up the idea of snow only to fade the idea within hours of the event. Oh well, we are now in the firm grip of some bone-chilling cold which will only intensify over the next 24-48 hours. My hats off to those brave souls who I can see by the Mad River single chair web cam are braving the elements.

Mainly dry through at least Saturday
Some of the bigger metropolitan areas will pick up a few inches of snow Thursday morning as a clipper system travels rapidly east on the wings of the polar jet. This is a suppressed jet as of now and we will miss out on the little available moisture there is with this system. We will instead have to settle for continued cold through Friday with temperatures approaching -20 in the morning and struggling to reach zero during the afternoons. The weekend will also feature some brutally cold mornings but the afternoons will be a bit more forgiving as temperatures climb well above zero. The wind this weekend will also subside somewhat alleviating some of the impact of this latest cold wave on Saturday and Sunday.

Manitoba's weather system
We do have a weather system to watch this weekend and a significant one at that. In addition its another weather event where major model disagreement is making it difficult for us prognosticators. And just like last week, the European model is suggesting a major snowfall while the American and Canadian models have backed away and are keeping most of the big moisture off the eastern seaboard. There is not a lot of room to play with. The eastern trough responsible for the cold will remain in place through the weekend but its width will collapse and it will have a very sharp but narrow look by early next week. Within this long wave structure comes the "Manitoba Mauler" with some rather impressive upper level vitality but with little moisture. If this system has a constructive impact with the Atlantic Ocean it could evolve into a major snow event for parts of New England. It could however do all its damage off the coast and be quickly written off as another "almost". It is important to note that moisture from this system is unlikely to make its way to the Green Mountain chain until late in the day Sunday. This leaves the door open for a big time powder day on MLK day but nothing much prior to that.

Beyond MLK...
In the wake of our MLK system will be some garden variety chill but we will see a moderation in temperatures as the week progresses. This happens as the strong western ridge migrates westward from British Columbia while at the same time blocking at the poles (as measured by the AO) index is at a minimum. This temperature moderation will be very short-lived in my opinion because the high latitude blocking which will be lacking next week will quickly re-intensify and the global long wave pattern will support a resurgent area of cold covering a broad area of North America. The warm-up next week could make room for a weather event that is briefly non-snow around the 24th. If we can avoid that however the coast will be clear for the duration of the month and the door will be open for additional natural snows in the last few days of January.