Think Snow, Tweet Snow !!!

Thursday, December 31, 2009

Sunday and Monday look epic at MRG as snow totals by early next week could approach 3 feet

Thanks now to the most recent run of the European model which is back on board with the more aggressive retrogression late on Saturday and early on Sunday. This was the critical piece of information that was missing and I can now be more affirmative with a 2-3 foot storm total forecast. The forecast covers a large expanse of time starting New Years Day and ending Tuesday of next week. Yes, Tuesday which means snow from this storm could be falling for 5 successive days.

I was a little scarce on details in my last update and since I am a little more certain of details I figured it would be time to disclose them before i celebrate the incoming decade. Snow on New Years day should be on the light side and should fall as a result of the decaying clipper energy. As the coastal low bombs east of Cape Cod we should see some enhancement in the precipitation shield Friday night into early Saturday but the storm will be well to our east and snowfall rates should as a result be gentle. Saturday's first tracks should see a few inches of new snow but my guess is less than 6 but the snow will continue to fall and as Saturday progresses, the storm will make this long talked about westward wobble or "retrogression". Such a motion to a storm defies the basic laws of mid-latitude "gravity" and it takes a powerful surge of upper air support to accomplish such. And yet, we expect it and as this happens late on Saturday the snow will intensify and become modest by Saturday night into early Sunday. NWS forecasts for the area would seem to downplay the event. I am not calling them out or calling them wrong but since the storm will ultimately occlude it will be sensitive to terrain and snowfall totals in the valley areas should be substantially less than the high country. At MRG, we could see an additional foot by "first tracks" time and another 6-12 by Monday followed by additional snows Tuesday. Epic indeed !!

Happy New Year to the MRG community. Happy New Decade. Think, think think snow. What a great way to finish one decade and start a new one !!

Wednesday, December 30, 2009

Expected storm track shifts east but....

not that far east. Far enough perhaps so that a repeat performance of 1969 or 2001 will be a bit tough. Far enough so that the threat of sleet has all but vanished if there was any to begin with. Close enough still so that much of northern New England, especially those sitting in areas with the "oragraphic advantage" should do very well over a span of several days.

The weather map on early New Years day (Friday) should consist of a gradually weakening clipper system over the eastern Great Lakes and a strengthening storm in the Virginia tidewater. Snow from the clipper should begin falling early New Years day. Accumulations will be on the light side because the snowfall intensity will be on the light side but it may be enough to fluff up the trails a bit. As we go through time, the coastal system will bomb and swallow all the remaining energy from the clipper. Models are still at odds regarding exactly where this coastal storm tracks and our forecast still remains uncertain as a result. The last three runs of the European ECMWF have taken our coastal system farther east and are not as dramatic with this westward retrogression on Saturday and Sunday. Such a solution would still mean snow for both Saturday and Sunday (Jan 2 and Jan 3) but accumulations would be on the lighter side and snowfall totals for the weekend will be in the 8-14 inch range by Monday morning. Snowfall rates would also stay on the lighter side in such a scenario and waist deep powder at first tracks time between Saturday to Monday would be a stretch. The American GFS model continues to show a very dramatic amplification with this system. The deepening is shown to be so fierce that the westward "retrogression" mentioned above would be the result. This scenario would put us directly in the thrust of the moist conveyor of this powerful storm and would do so for multiple days. Accumulations would be on the order of 30 inches by late Monday with epic powder Saturday, Sunday and Monday.

Having faced this fork in the road many times in the short history of the SCWB I have typically found faith in the European model since it has proven to catch a trend or shift prior to the American Model. This instance would be no different except that in doing so I would be disrespecting the potency of systems coming out of the southern branch and up the east coast. Most of these systems this year have been stronger and tracked farther northwest relative to the consensus of models. I will therefore cautiously predict 1-2 feet over a 4 days period and at the same time purchase the "huge margin of error" insurance policy.

There is always concern with any system with strong winds closing lifts. This has typically been a bit out of the SWCB domain since I would hate to wrongly steer people away or toward MRG as a result of a wind forecast. Wind and wind holds are always a risk and winds will be gusty through the weekend since this is an intense storm with a tight pressure gradient. I will say that in my 10 years skiing regularly at MRG, the wind holds on the single have resulted from strong easterly winds at the summit. Winds will be strong throughout the weekend but they will not be blowing from the east and will instead be much closer to north. Does this save the MRG single from wind holds ? No guarantees, but for those that requested the information, there you have it.

Garden variety cold will grip the Green Mountain chain through next week but when the dust, fluff and powder finally settle from the New Years storm the storm track will be suppressed well to our south and our snow will be the result of clipper systems and terrain enhancement. Blocking remains in the jet stream but there should be a gradual shift from a cold pattern energized by the NAO to a cold pattern supported by a positive PNA. This in the need could send bitter chill into New England sometime after January 8th.

I will try and provide updates as often as a I can but tomorrow is a holiday and my presence is needed at work so an update might not come until late New Years day or early New Years day.

Monday, December 28, 2009

New Years storm 2010 is a few days closer and more certain !!

And conditions should have already recovered somewhat thanks to what should be several inches of terrain enhanced snow on Monday and Monday night. The snow will be "enhanced" by both terrain and an arctic boundary which is expected to arrive on Monday night. A short burst of heavy snow is possible with the passage of the boundary and should help to produced a 6-12 snow total by first tracks time Tuesday. Tuesday will be cold and blustery but not unbearable. Temperatures will be in the single numbers and wind chills will be below zero but I have skied at MRG in worse, much worse in fact. Visibility should improve by Wednesday and a very cold, sub zero start will give way to comfortable temperatures in the afternoon. And thus the stage will be set for perhaps the best start to a year any of us MRGers could possibly imagine.

This storm, if it comes together will be nearly a perfect nexus of southern branch moisture and a vigorous surge of upper level energy from the northern or arctic branch of the jet. The result will be a massive eastern U.S. trough with cold air stretching to the Gulf Coast and beyond next week. It is possible in fact that snow is falling on the Florida panhandle at some point next week as well as some other semi tropical locations. The storm will look a bit innocuous as it brings its disorganized area of rain into Virginia on New Years Eve. Arctic jet energy will then arrive and bring its rocket fuel into the mix. The storm will intensify very quickly as a result and the intensity of precipitation will enhance as the storm rather slowly makes its way up the coast and positions itself in the Gulf of Maine late on New Years Day.

If everything goes as advertised, snow at MRG will begin during the day on New Years day and turn heavy during the evening. What makes this situation potentially special is the ability of our eastern trough to continue digging long after snow commences. This will allow the storm to pivot and attain whats referred to as a "negative tilt" greatly elongating the period in which it snows on the mountain. There are in fact indications that the strong surface storm will retrograde from the New England coast inland as it occludes. It could result in several days of snow and epic powder and a nice payback for another rainy Christmas. Its probably a little early to get too buried in accumulation predictions but the reader should get the idea. 2010 is expected to start snowy and there are no indications of warmth or rain through the first week of the month. Enjoy it for there will surely be some adverse times this year but the next 10 days should be spectacular.

Saturday, December 26, 2009

March 2001, Valentines Day 2007 and New Years 2010 ?

And what might might all those dates have in common. For the purposes of pleasing the karma gods I will leave the answer blank. Plenty of uncertainty remains and plenty of time for the potential to unravel but the potential exists and for something big to occur it needs to start with "potential".

Rain and ice has indeed made it to northern and central Vermont and has thus humbled this prognosticator who a not more than two weeks ago declared that such a thing would not happen for the duration of 2009. This storm has obliterated portions of the northern plains with snow and wind but is hardly impressing any of us skiing enthusiasts since it lacks both moisture and cold air and we will gladly tell it to not let the door hit it on the way out. Its "out" will allow a pool of deep instability to move over the state of Vermont and this will allow snow showers to become heavy in the afternoon on Monday. The snow will continue in some earnestness overnight Monday and Tuesday should turn into the best day to ski although a cold and blustery one as arctic air resumes its grip on MRG. Snow accumulations Monday and Monday night will be hard to predict but this is a good set up for terrain enhancement and 6-10 inches of fluff is certainly realistic prior to first tracks time Tuesday. For those wondering about Monday, temperatures will be below freezing for much of the day but I don't expect snows to accumulate until the afternoon.

Snow showers will taper to flurries Tuesday but temperatures will struggle past 10 and will fall to below zero levels by Wednesday morning. Both Wednesday and Thursday should be mostly dry with the exception of a few flurries Wednesday. Winds should diminish and the cold will diminish to some extent Thursday as temperatures climb into the 20's. The storm on new years rides on the ability of the juicy southern branch of the jet phasing with the vigorous amplification of an eastern United States trough. This trough will ultimately bring cold air deep into the south as 2010 begins. Models are having a difficult time with the southern branch moisture as usual but both the European model released late on the 26th and the American GFS model released early on the 27th (GMT) show a phasing and a "bombing" south of Long Island. In addition, the deepening trough across the eastern part of the country and blocking downstream across Greenland will allow the storm to move slowly if it can successfully form. The potential thus has me very excited and referencing historic and similar type storms such as February 1969 and March 2001. Are search for the right ingredients is over its just a matter of getting the right proportions and watch things explode. Its not a done deal yet but worthy of our attention.

I should add before signing off that the timing of snow is still up in the air somewhat. Snow should it happen would arrive New Years day and potentially continue for a few days or not happen at all. Lets wait a day or two and re-assess.

Thursday, December 24, 2009

2009 may end with a bang !!

Dry air stemming from high pressure center over Quebec will help improve visibility through Christmas. We won't see much in the way of snow through Christmas day but light winds and seasonable temperatures should provide the opportunity to loosen up the legs on the groomers. We have been watching our post-Christmas storm for more than a week and in the end it will be a disappointment. Precipitation will arrive in the form of snow late on Saturday and is likely to turn to a mix of sleet and freezing rain for a time on Sunday. The problematic layer of warmth is only indicated to be about 1-2 degrees C so the possibility of turning this to a snowier forecast remains but chances are starting to dwindle. Temperatures at the surface will struggle to get above freezing and if they do, it will hardly dent the base. This storm in the end will be a much greater concern for the Upper Midwest and its impact on the east will be forgotten about in short order.

I am much more excited looking at the possibilities for Monday. The storm as discussed will occlude across the Midwest and will ultimately bring a deep pocket of instability across New England Monday. The unstable layer could for a time be greater than 10,000 feet which would be more impressive than at any point last year. With the winds at varying levels of the lower troposphere aligning, the prospects for terrain enhanced powder look very good Monday. So good in fact that I can confidently say much of the Green Mountain chain could get a 6 inch or more shot of powder during the day Monday. Arctic cold arrives Tuesday and although snow showers should continue the chances for an accumulation drop off. The drop in temperatures will also not go unnoticed. Temperatures should hover in the low 20's with snow falling at oscillating intensities Monday. Readings will fall to the single numbers however for Tuesday and Wednesday and wind chills will be well below zero for Tuesday.

Our southern branch might be cooking up more of the good stuff around New Years day. In the coming days, I think some of the medium range models will come up with some sort of consensus that includes an east coast storm and perhaps a big one around New Years Day. There is so much jet energy along the Gulf Coast that it is proving very difficult for the models to make sense of what to do with it all. We have already seen a few occasions where model data is simply underdone on the potency of this jet energy along the Gulf Coast. You can't call the American GFS model underdone this morning as it "bombed" a storm off the New England coast New Years Day. The European shows a much weaker version. One might normally bet on the more benign of the two advertised scenarios but I would not want to fight the southern branch this year so lets be cautiously optimistic and see if this can sort itself out into a snowy forecast for us as 2009 ends and 2010 begins. Ensembles have also given us the gift of an extension on our blocking pattern which will include favorable NAO and AO teleconnection indices through the first week of January.

Tuesday, December 22, 2009

Models showing a cooler post Christmas storm, trend needs to continue a bit more and we are gold

Trying to combine a bit of last minute Christmas shopping and Single Chair Weather Blogging which is a bit trying. The news is mixed regarding the storm which is set to bring precipitation in the days following Christmas. Taken literally, the models are still suggesting a period of ice but this period has been minimized and the storm profile in northern and central Vermont looks cooler, enough to support snow for a period late on the 26th. This is a strange system where much of the energy will get rung out across the Midwest. A new storm system will form and strengthen along the Atlantic coast and bring precipitation into a rather stale airmass. Dry air will help keep precipitation in the form of snow for a time but it will also delay precipitation almost a day from what was expected during the last update. The snow could also be wet in nature. Whether or not it goes to a period of ice or rain is still up for debate but if it does happen, against my wishes it will not amount to anything close to the X_Mas thaw last year which was a crusher and closed MRG for weeks.

Conditions should also get a boost from terrain enhanced snow which will arrive on Sunday night into Monday and continue conservatively for 1-2 days. This snow should get an additional boost with the passing of an upper air disturbance in this time frame. I will take a closer look at snowfall potential between the 28th and 30th in an update tomorrow. We may also get a clearer view on what could be a bigger event in the days following new years.

Sunday, December 20, 2009

Model data delivering a rather frustrating result for Christmas event

And although I am holding out hope, I have to respect what the consensus of data has shown over the last 48 hours. If true it would be a very humbling turn of events for me since some aggressive proclamations were made. I will stick to these prognostications for the time being but at the same time I will reveal the details of the less than ideal model simulations.

While many along the eastern seaboard are no doubt digging out from one of the more historic December noreasters that I can remember, MRG will continue to remain dry through part of Tuesday with temperatures in the teens during the day and near zero at night. A weak disturbance will rotate into the departing east coast trough Tuesday and will enhance snow shower activity for a time and may help in bringing a fresh inch or two to the mountain. After that, we wait for the storm which departs the Rockies Wednesday with vigor and tracks toward the northeast.

Although we continue to see plenty of blocking in the jet stream which will persist through the end of the month we will temporarily lose our supply of fresh cold air this week. The below normal temps early this week will gradually modify as the airmass becomes stale by Christmas Eve. At the same time, models are suggesting that our Christmas storm takes a left turn in the southern Plains and heads for the St Lawrence Valley. It is honestly hard to believe such a track given the state of the AO and NAO but models have been spitting out such a solution for consecutive days. The adverse track of the storm will be mitigated to a degree as the storm transfers its energy to the Atlantic Coast, but if the models are taken at face value, snow will arrive on Christmas day and turn to ice before ending as a period of terrain enhanced snow over the weekend. I am not throwing in the towel on this event in spite of all these details. Below normal temperatures have helped to chill the Great Lakes and much of the east is under a healthy blanket of snow. These are subtle variables but over time can act to keep the track of this storm farther south. Blocking in the jet stream can also encourage such a storm to make a quicker transfer to the Atlantic Coast thus thwarting any warm-up. I am no doubt concerned about what the models are saying but this game is hardly over, lets see how things transpire in the coming days before officially throwing in the towel.

Ensembles continue to show a "blocked" pattern through the end of the year with weakened but still favorable teleconnection indices. Model runs over the last 24 hours have been on the drier side with snow falling mainly from clippers and terrain enhancement. There remains evidence however of an active southern branch of the jet stream so one has to be somewhat cynical of a dry forecast.

Friday, December 18, 2009

Major winter storm to pummel the northeast but miss MRG

I am sure the blog has plenty of readers in the big city locations who are getting slammed with news and hype regarding the upcoming winter storm. This system was discussed Thursday in more benign details and major media outlets are now using much stronger language (no doubt to assist in the ratings war) to talk up the weekend storm. In this particular case, the storm will prove worthy of such language. It looks very similar in many respects to another historic storm in another El Nino year commonly referred to amongst us weather geeks as the "Megalopitan snowstorm of 1983". It like this one, formed in the Gulf, moved off and up the Atlantic Coast and absolutely crippled the northeast corridor with historic snow. The heaviest of this snow occurred during a Friday rush hour where the rate of snowfall increased to as much as 5 inches per hour leaving a few motorists stranded in some very unexciting locations (Like the ramp of the Lincoln Tunnel). This storm will bring similar type snows to many of the same locations and will make all sorts of headlines and may enter the record books in a few spots. At MRG, it will be just another day and a dry one at that. The snow will fail to make it to our beloved location and we will simply have to look ahead for our next opportunity.

I have received a few emails regarding the Christmas event and a few of these emails have expressed concern about recent model data. Yes, there have been hints of a less than optimal track to our Christmas storm but I will not be a "model hugger" and would rather try and see the forest for the trees. This is a little pretentious on my part and I apologize in advance but my view has been that rain or ice will have a difficult time impacting MRG for the rest of the month. We have a vigorous and very favorable blocking pattern and I think it will work its magic and prevent these adverse situations such as rain or ice. This storm is another El Nino driven product and it will advance through the southern Plains during the middle of week before becoming "occluded" somewhere in the eastern third of the country. An "occlusion" occurs when the upper level low pressure center and low level low pressure center are on top of each other or "vertically stacked". It will prevent the storm from reaching historic proportions and it will wrap some mild air into coastal areas of the northeast around Christmas time. The details are still a little hazy but I would expect some modest snows Christmas Day and some significant terrain enhanced snow for at least a day in the wake of this storm. It should prove to be a good weekend for skiing but time will tell. Storms that are vertically stacked rarely deepen but they have a favorable stability and shearing profile for terrain enhanced snow and I would expect to see that in the forecast in a few days.

The pattern will remain blocked through the new year although relatively free of extreme cold. I would expect to see the continuation of an active southern branch of the jet stream and another storm around the start of the upcoming decade !

Wednesday, December 16, 2009

Chilly pattern will turn snowy around Christmas, maybe sooner if we are very lucky

It will take more than luck to get a powder day Friday or Saturday. Very dry air and the low and mid levels of the troposphere combined with a rather unfavorable shearing environment will make terrain induced powder very unlikely for the re-opening of MRG. The pattern, as promised, has turned quite favorable but the fruits of mother nature's labor usually waits, sometimes up to a few weeks. I would remiss however were I not to mention the trouble lurking in the southern branch this weekend. The same branch of the jet stream responsible for the rain across the Gulf Coast and lots of it. This is a very common byproduct of El Nino and it has been very evident so far this winter. The southern branch of the jet stream will prove its worth this year on more than one occasion. One possible occasion could come late this weekend as energy in the southern branch creates a significant precipitation producer over the Carolinas and Virginia. Models suggest this system goes out to sea from here with little impact on the northeast. I think models may suggest this time and again with many systems this year and on one or two occasions these systems will turn out stronger, amplify the pattern more significantly and surprise the northeast with big time winter weather. It is unlikely this happens Sunday evening into Monday but its worth watching how models handle this system going forward.

Our next system and one certainly worth our attention arrives around the time of Christmas Eve. It is a more organized system which will exit the Rockies during the middle of the week and progress east. The track of this system will be farther south than a similar system last week. It nonetheless appears to be our best chance for significant snows. It is a bit early to prepare for a big event as many things will change as the looking glass is de-fogged. I am optimistic however for a nice little Christmas thumping. Santa still owes me for 2005 so perhaps he will deliver the goods this year.

No change to the very optimistic balance of the month outlook. Expect a few more opportunities for snow through the duration of the month and a very minimal chance for rain. Not going to say it can't happen but the chances this year are substantially less than in any other Christmas holiday blogged here at the SCWB.

Monday, December 14, 2009

"Block" of gold delivers a powdery ride through the rest of 2009

And since the SWCB is funded by nobody, it allows the writer to make some politically incorrect prognostications. Like to suggest that the holiday week defined by the period between Christmas and New Years will be one of the best such periods ever perhaps similar to 2002. It is a risky proclamation to say the least but the crystal ball can look very hazy sometimes and this may be one of those times when one can make out a few things through the haze.

A brief mild break in the weather will end Tuesday with a few inches of wet snow. Much colder air will bring another inch or two of fluff Wednesday but the end of the week will be remembered for the coldest weather of the season so far with temperatures in the single numbers during the day Wednesday and Thursday and below zero temperatures at night. The polar vortex responsible for the cold will more or less get forced under the blocking in the jet stream this weekend and although the cold will modify slightly, some below zero wind chills will remain. We won't be talking about any organized weather systems this weekend although there will be weaker disturbances rotating around this upper air vortex and will likely deposit a few inches of terrain induced powder.

The pattern will turn active beginning around the time of December 22. It may take a few more days for such a change to manifest into actual big snows for the mountains but if systems in the southern branch remain out of our reach, we should still be on the receiving end of a barrage of clipper systems. The combined forces of the North Atlantic and Arctic Oscillation should allow for even bigger things however such as a more profound jet stream amplification and a major east coast system. There shouldn't be a shortage of systems passing through the Rockies and moving across the southern half of the country the last 10 days of 2009. We would just need one of these to systems to catch an injection of energy from the Polar Jet and away we go.

Friday, December 11, 2009

Pattern delivers an early MRG opening !

The oragraphically enhanced snow that was missing for a good part of last year has arrived early and brought the kind of fluff that can provide those "soundless" turns. Its one of the best feelings one can have and I live for those early powder turns and there should be a good amount of that as MRG officially kicks off the season. Some additonal powder can be expected through Saturday afternoon as the atmosphere undergoes a very gradual stabilization. I would not be surprised to see an additional 5-10 inches prior to the 10 AM commencement ceremonies. Saturday will continue to be blustery and cold with temperatures in the single digits and teens. Sunday will turn into a nice one, with some early sunshine afternoon clouds, light winds and afternoon temperatures which climb to the freezing mark.

Why not continue to rave about the upcoming few weeks since the eastern ski resorts and Mad River Glen in particular can certainly salivate over what appears to be one of the best weather patterns one can hope for as far as good December skiing is concerned. We have seen plenty of inconsistency in December, a month which can deliver plenty of cold but plenty of rain. Such will not be the case this December. A furious blocking pattern has emerged, sending the North Atlantic Oscillation plummating deep into the negative category. I am trying to remember if I ever remember the index itself at -3 and it may approach that in the next 10 days or so. The oscillation itself is indirectly driven by massive block in the Jet Stream over Greenland that is expected to extend across much of high latitude North America or the Nunavut region of Canada. After a brief reprieve the cold weather early next week, temperatures will plummet on Wednesday and will remain slightly below normal through the Christmas holiday.

As far as specifics on storms or new snow, there is not much on the immediate horizon as far as major snows. Some wet snow is possible Monday (the one time frame where temperatures may warm to above freezing. Additional snows are then possible Tuesday into Wednesday in association with the incoming arctic air. This system has a slight chance exploding off the Atlantic coast and providing more than the 2-5 inches that I might guess would fall at the moment. A clipper system late in the week could then bring another light accumulation of snow before which should be a chilly weekend before Christmas.

Big storms, the ones which are really good for SCWB ratings are unlikely until Christmas week but the pattern is certainly capable of producing such an event between the 20th and 25th of the month. Considering how "blocked" the pattern has become, major weather systems will find some resistance as they proceed up the Atlantic Coast (if one becomes organized enough to do that). It will thus ultimately be a question of whether the pattern allows for a major weather event to track far enough north for major snows. I would guess though that we get at least one major event before the new year. The pattern will turn ripe for it and we should be ready and have our ski's tuned up for the occasion !!

Wednesday, December 9, 2009

6-8 inches of snow/sleet/ice followed by some early winter chill

And for those who are lucky enough to have a day off Wednesday, there will be some morning powder across the northern half of Vermont as it appears snow will fall in earnest through early afternoon. Temperatures and more importantly, wet bulb temperatures (the lowest temperature that can be reached through the evaporation of water)are such that Wednesday's event will indeed consist of several hours of powder before precipitation goes to sleet and a very brief period of freezing rain later this evening. The storm is far from epic but will, as promised, prove to be a good primer for a base which should steadily build over the next several weeks.

Snow of the terrain induced variety will return by Thursday morning and continue in at varying but mostly light intensities through a good part of the day Friday. The unstable layer providing support for the snow Thursday and Friday is relatively shallow as it often is when arctic air invades the state. Nonetheless, we should see additional accumulations of 4-8 inches before it dries out over the weekend.

There is no need for any lenghthy addendum's on what still is a very optimistic outlook through the middle of the month and perhaps now through the holidays. The pattern will be driven and driven quite hard by a ferociously negative NAO and AO over the next several weeks. This will keep temperatures on the cold side and most impotantly will keep the rain out. The American GFS model showed the second coming of March 13th, 1993 on one of its runs yesterday but it lacks support from other model data including subsequent runs of the GFS. There is a potential for snow in the early to middle part of next week. This is an east coast system that will try and intensify at the last second or pass us by in benign fashion. Next week will then finsh similarly to this week with some terrain induced powder and cold temperatures. More on the long range this Friday.

Sunday, December 6, 2009

Hopes for epic powder on Wednesday fade but favorable pattern remains

And although it would seem as if we have made it through a long stretch of unseasonably mild weather we have yet in fact to reach categorical below normal temperatures and may not really do so until later this week. It is however cold enough so that the little that did fall Saturday will remain in place as the next very closely watched system approaches late Tuesday. This system has potential but its track has become problematic and each run of the very trusted European model seems to confirm that our prospects for big powder from this storm are fading. This system can still do a lot of good as far as priming the base for future events.

The system in question is poised to clobber the interior west from the Sierra Nevada mountains to the continental divide in Colorado. It will then tap into moisture from the Gulf and move northeastward. It should prove to be quite an event for portions of the Upper Midwest but its track as it continues to push toward New England will allow warm air to invade critical layers of the atmosphere. This movie has been played out before many times and often warmth from the Atlantic can get pinched off as energy gets transferred to the coast. I expect this to happen to a degree but the event will nonetheless consist of snow to start followed by a change to sleet before ending as a few days of terrain induced powder late this week. I think the uncertainty at this point revolves around precipitation type and the particulars regarding how much snow verses sleet verses freezing rain verses dare I say rain. Sleet would be the ideal primer and we should receive a healthy dose of that Wednesday but hopefully we can keep the freezing rain and rain out. The European model would suggest that this could be a challenge while the American model says sleet will likely be the primary precipitation type Wednesday. I would say around 5 inches of snow and sleet is a good initial guess on this event. Remember however that sleet is exponentially more dense than snow and that a few inches of sleet has tremendous staying power were it to fall. With powder seemingly becoming more far fetched I am pulling for a "sleety" outcome as it will be this which will get MRG open the quickest in my opinion.

Much colder temperatures will advance into Vermont Thursday in the wake of this storm and preliminary indications suggest two days of a cold and not entirely dry westerly fetch of air. Such a setup should provide a shallow layer of instability and terrain induced snow leading up to the weekend. More details on that later in the week.

I am becoming more impressed with the "sustaining" power of our new high latitude blocking pattern. It may have started with the "Omega Block" across Alaska but will evolve over time into a combined negative AO-NAO fueled jet stream configuration. This should be one where the jet stream is forced southward and where rain events and even thaws will be tough to come by. I am going out on a limb here and will suggest that all precipitation after Wednesday's event and up into the time of Christmas will be snow. Hopefully we won't let the opportunity to build an early season base pass us by. My guess is that we will not and should go into late December with my kind of holiday cheer !!!

Friday, December 4, 2009

Storm talk speculation ? Let the games begin !!!

The cold air has made its long awaited arrival and the snow is on its way, proving once again that El Nino's can "put out" and often do so in quantities. The southern branch can also never be underestimated and its up to old tricks this weekend, energizing another system in the gulf states and sending it northeastward. I didn't give this system much of a chance to be quite honest and quite recently sent an email to a loyal SCWB follower to essentially squash his hope. This is a system that will in the end track a bit too far east for a big hit but I do expect the precipitation shield to reach much of Vermont and deposit a few inches of snow to the Green Mountain chain late Saturday before it makes its way into the Canadian Maritimes. Big snows can be expected across the Monadnock region of New Hampshire, which is a region of New England that is often overlooked as far as exciting weather goes. Its close enough to the coast to get the effects of some intense noreasters yet high enough in altitude so that many would-be rain events turn into big snows. This is one of those situations where the Monadnock region can see a foot or more of snow while locations along the coast get rain and the likes of Jay Peak struggle to see an inch.

The global long pattern has indeed become "blocked-up" as expected and the results came very quickly with snow falling at some unusual latitudes such as Texas. The blocking catylist however is situated across Alaska which can create some competing negative impacts on our weather pattern going forward. The most important of these potentially "adverse" impacts is the energy that is expected to dive under the block and into the open waters of the Pacific. It will surely help to create an onslaught of storminess on the west coast (California as opposed to British Columbia) and I would expect some unbelievable snowfall totals from Tahoe and other portions of the interior west over the course of the next two weeks. Farther east however the effects of the energy in the Pacific can be a force for the creation of a mid-continent or southeast ridge. This ridge will be or won't be an issue next week as a major system sweeps across the country. It is expected to evolve into a major winter storm for the upper Midwest and perhaps even a blizzard and then continue toward the northeast United States. The track of this system during the middle of next week is, as you probably guessed, the 64 thousand dollar question.

The playing field next week appears similar in some respects to late December 2002 when a system of similar potential crossed the country and questions regarding the strength of a southeast ridge loomed large. In the end, the El Nino, of a similar strength to this year beat the southeast ridge to a pulp and the storm pulverized interior New England and brought some of the best X-Mas skiing to Vermont ever. I have faith that this El Nino can perform up to 2002's standards especially when combined with a very negative NAO. I therefore am cautiously expecting a big event beginning early Wednesday and persisting into Thursday. I am currently watching the latest and just released information from the European model which suggests a snow to sleet then back to snow type of progression. Such a result would be a great base-building" type of event and if the storm tracks 200 miles further south the results could be more incredible with snow in feet and some epic early season powder.

Beyond the storm late next week, appears to be a pattern marked by a very negative AO and NAO. The pipeline of viciously cold arctic air appears a bit closed off so I would expect temperatures that are more or less seasonable but with a minimal threat for rain and a very little in the way of above freezing temperatures. We should therefore be able to gradually add to whatever base gets laid down next week and should be in good shape as we approach the winter solstice. Information from the American model suggested a big storm around the middle of the month this morning but the ensembles are indicating a pattern which might be free of storminess during this middle of the month period. Its tough to predict such weather during an El Nino but it is at least a possibility. At the very least, I am happy to report generally favorable weather beyond the middle of the month thanks mostly to the favorable teleconnections indices of the Arctic and North Atlantic Oscilation.

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