Think Snow, Tweet Snow !!!

Saturday, January 31, 2015

I got the welcome mat out for a storm that now seems headed our way !

Did we will the Monday storm northward ? I don't know, but if we did we should bottle that strategy and store it for future events. The Monday snow is back as models continue to violently waffle this way and that way on about everything. It has been a forecasting headache for many of the NWS forecasting offices who have scrambled rather admirably to keep up with the ever-evolving picture. Washington DC for example seemed like ground zero for 6-12 inches with temperatures in the 20's while much of New England remained dry. This scenario would have the low pressure center tracking along the Virginia/North Carolina border Monday. Now however, the storm is expected to track across southern Pennsylvania to the New Jersey coastline and proceed to do roughly a 50 mile hug with the southern New England coastline. This track is not the most optimal one for us at MRG, but good enough and far better than the former. Washington DC, by the way will wake up to rain and temperatures in the 40's Monday, quite a shift in the forecast over a 36 hour period.

If we can get another 50-100 miles north on this storm track perhaps we can get our foot of snow. For now however I think it's yet another storm in the productive 5-10" category. This will be a cold storm as well with a fresh supply of arctic air reestablishing itself just as the snow begins to fall around day break Monday. Snow should continue to fall at a light to moderate clip for much of the day with temperatures falling to near zero and later below zero as snow tapers off during the evening. After a very chilly and mostly sub-zero Tuesday, a midweek clipper could spread some additional snows into the region later Wednesday into Thursday. Not a bad way to start what I expect will be a terrific month of skiing at MRG. 

Thursday, January 29, 2015

BC Bomber turned Gulf of Maine bomber should bring a nice dose of Friday powder

This nice little BC Bomber type system should serve us quite well on Friday and provide the mountain with a nice powder day. We haven't seen too many events like this over the past few seasons but they do occur frequently and produce positive results just as frequently. Light snow should overspread the region Thursday night as the relatively benign low pressure system approaches. As the storm interacts with the relative warmth of the Gulf of Maine, it will intensify quite rapidly and precipitation will enhance along the northern and western flank of the deepening system. The high country of the Green Mountains will also get aided by terrain effects and a nice fetch of moisture from the fast flow off Lake Champlain. Flow which should enhance late in the morning and continue through the day and into Friday night. It's not incredibly unstable so I don't expect huge amounts of snow, but another 5-10 is reasonable on top of the approximately 5 we got on throwback day is not too shabby.

Light snow or flurries continue into a very cold Saturday. We've had a few days this week and this month where temperatures have struggle to climb above zero and Saturday will be another one of those days. Blustery northwest winds will keep wind chills in the vicinity of 20 below throughout the day. Sunday will be the more comfortable of the two weekend days with temperatures recovering back into the low teens along with relatively calm winds.

We've been watching Monday's potential weather system for some time now and the plethora of models that have been released over the last 24 hours have all taken this system further south by a few hundred miles. This keeps snowfall well to the region's south and this scenario would allow cold to overwhelm the region once again early in the week. I am not completely selling my soul to this idea just yet given how poorly the medium range models have performed this winter but would not be surprised by it either. The polar jet is back in a big way early in the week and it's proximity to New England will have the capability of shunting any nearby weather systems eastward. This same "PJ" can bring a clipper system into the region for the middle of the week before more cold arrives around the 5th or 6th of February.

There are signs beyond February 8th or so of a significant temperature moderation and at least a temporary reconfiguration of the long-wave or jet stream pattern. I think the teleconnection indices, particularly the NAO/AO strongly support the receding of the polar jet in this time frame but I do not at all buy into the idea of a significant warm-up for February. The Pacific- Decadal Oscillation and the continued presence of warm water across the Gulf of Alaska and the west coast of North America in general will make it extremely difficult for any upper trough to gain  a persistent foothold. This means any temperature moderation across New England would be slight as opposed to dramatic and that the door should be wide open for potential snow events. In short, I think we can look forward to a good month of February with plenty of excitement.

Monday, January 26, 2015

5-10 windblown inches form massive New England nor'easter

A couple more cycles of data have been released and some slight modifications to the forecast are required. The storm track has shifted east ever so slightly. Ideally we would want a low pressure center to track west of Cape Cod (at least the eastern tip of Cape Cod) and even more ideally right over Boston. As this storm bombs south of the Cape it will make every effort to reach that eastern tip but the latest models have it falling just short. Still, I expect we will see a good band of snow rotate back into the region from the south and east during the early part of the day Tuesday. Snow should begin at or just before dawn and some moderate snow is probable for a while during the morning beginning right around first tracks time. The heaviest snow will be well off to our south and east. The Monadnock region of New Hampshire should do extremely well and much of eastern Massachusettes and Rhode Island will perform even better (perhaps 25-35 inches in spots). Here at MRG, I am expecting a wind blown 5-10" and I mean it when I say wind blown. Winds will become very feisty during the day, mainly out of the north and will cause lots of blowing and drifting both on and off the hill. Snow will taper to flurries during the overnight hours and will give way to a blustery and chilly Wednesday. Temperatures will hover around 10 through much of the storm and wind chills will be well below zero.

Nice looking BC Bomber type system is showing up for late in the week. Not huge amounts of moisture but enough for a decent period of snow Thursday night into early Friday and another several inches is certainly possible. Still expecting an invasion of bitterly cold temperatures for early February (Feb 1 or 2). Interestingly, there is some uncertainly regarding the way in which the cold invades. Does a more organized weather system mark the leading edge of this cold or is just a benign clipper system. The Euro is not suggesting any activity out of the southern branch or subtropical portion of the jet yet other models are leaving the door open for such activity. Not a bad pattern though, no thaws on the horizon, lots of cold weather and hopefully the snow continues to pile up.

Saturday, January 24, 2015

Expectations for Tuesday's potentially monster nor'easter shifting dramatically

Humbled and a bit embarrassed, yet full of exciting news. This is a pattern loaded with potential and in two updates a potential storm was discussed in the upcoming Monday/Tuesday time frame. Yet, I totally threw in the towel this past Thursday as it looked like the polar jet would do a "squash job" on a promising looking storm. This aforementioned polar jet is expected to be a little softer early in the upcoming week. It's such a subtle difference but oh so critical. The clipper system Sunday is expected to dive into the Midwest as expected and then begin evolve into a monster coastal system near Cape Hatteras. The polar jet would be capable of providing the westerlies necessary to drive a strengthening nor'easter out over the ocean but the jet a bit weaker and a bit farther north (verses expectations a few days ago), this storm can do its thing. 

I have alluded to the erratic performance of the models this winter and this event underscores that point. That and models continue to "evolve" in regards to the handling of this event. Intensity, track and the eventual precipitation field have all been altered dramatically over the last 24-36 hours. This being said, the "evolution" may continue and expectations will need to be refined after the next few cycles of model simulations. Snow is a lot more likely at MRG for Tuesday but I am not ready to guarantee a huge dump yet, at the very least though some snow is likely.

From Cape Hatteras, the storm is expected to explode later Monday and get sucked toward Cape Cod. If this does indeed go down this way, and the low does indeed deepen to sub-980 mb, as the lastest pieces of info have suggested, snow will move into the area early Tuesday and become heavy for several hours. The snow would be accompanied by wind, cold temperatures and treacherous road conditions. Though there is data supporting a 10-20 inch dump, and yes I think that can certainly happen, I want to caution my fellow powderhounds. We could see some additional changes. We could still see less than 10 and yes, we could see more than 20. Lets wait another 24 hours and see how things look. I also want to point out that this system could become a nor'easter of historic significance for portions of the northeast. Eastern Mass, Rhode Island, Connecticut even New York city could memorable snowfall totals and the biggest storm in a few years.

I'll have more on the long range in a subsequent update, but temperatures will be cold in the wake of the storm during the middle of the week. A clipper dives to the region's south Thursday. This is a potent little system and though it could confine most of its impact to locations south of us we could see at least a light accumulation. Flurries and snow showers follow for Friday and perhaps into Saturday the 31st ahead of a more major jet amplification late in the weekend. Models for several days bring the full ferocity of the polar jet, possibly even the whole polar vortex over the eastern Great Lakes for early February. Extremely cold weather and possibly some snow out in front of all that Sunday is possible. The cold would linger through February 4th or 5th before receding allowing for a slow moderation. 

Thursday, January 22, 2015

Looks like we swing and miss on both storms over the next few days I am sorry to say

Weekend storm comes close, very close, but this area of low pressure will pass east of Cape Cod and move northeast from there. Parts of eastern Mass, southeastern New Hampshire and eastern Maine will see some good snow very late Saturday and into Sunday but we needed this storm to track 100 miles further west for a significant dump. A shift in the "11th hour" is not impossible but not likely given what the consensus of data is indicating. Temperatures will sneak up to within a few degrees of the freezing mark on Saturday making it one of the milder days of the month so far and perhaps the last chance to eclipse the freezing mark until well into February. The milder temperatures, albeit the brief appearance, will come in advance of a clipper system that arrives late Saturday into Sunday bringing much colder air with it. I had hoped the clipper would bring some replenishment with it, but coastal system will steal some of its thunder and prevent that from happening. Still, we could see some snow showers and an inch or two Sunday if we are lucky. Temperatures Sunday will remain in the teens and plummet in to the single numbers during the evening.

The second of the two potential coastal storms will get squashed by the weight of the polar jet early next week. It was just a timing issue in this case. If Monday's system could have arrived a bit quicker, we might have had a phasing and a nice accumulation up this way but the snow will fall across southern New England in this set up while bitterly cold, dry and unmodified arctic air dominates the region in its stead. Temperatures will be sub-zero Monday morning and struggle to reach 10 during the afternoon. Tuesday will be a repeat of Monday.

The polar jet will be a persistent force throughout the upcoming period through the early days of February before receding around the time of February 4th. It will be tough to get an organized storm system from the southern branch of the Jet but we can continue to see clippers and we should see one in the later part of next week. This will mark the advance of another reinforcing blast of cold and hopefully some snow will accompany the advance of this chill. There are indications of some extreme temperatures in the time frame between January 31 and February 3rd. We could see a clipper or a disturbance bring some light snow but unless we see some fundamental chances in this pattern, much of the big precipitation will likely fall to our south. This is typical for January around here and honestly I am happy to get through the month without a major thaw.

The upcoming cold is being driven by the persistent ridge across western North America which is expected to strengthen briefly late next week before retrograding into and evolving into a high latitude block across the Bering Sea. The jet stream in the Pacific is expected to remain loose however and this means arctic air should remain on the playing field. Can't complain about a pattern that continues to support some cold and not one dominated by the "evil empire" but it's unfortunate about the two misses and what looks to be a drier forecast in the days that follow. Hopefully something intriguing shows up on the ever-changing weather map sooner than later.

Tuesday, January 20, 2015

Watching two more potential storms over the next week but both are far from guaranteed

2 days and 15 inches of snow since the last update and once again there are some new forecast ideas that will require an introduction while other ones might need to be scrapped. The changes today are not quite so drastic compared to last week but it is nonetheless remarkable how inconsistent medium range forecast ideas have been. Even the normally reliable European model has generally failed to lock on and stick to an idea for more than a day or 2. The American GFS model ? Well, this numerical weather prediction package just underwent a major upgrade where the resolution was increased in the long range, product fields were added and model components were changed amongst other things. The results on a strictly empirical level certainly leave something to be desired. Typical GFS model biases remain and these biases seem to result more from problems with the model physics than any resolution related shortcoming. I digress however. Numerical Weather Prediction are the fruits of some hard labor by many others and it has made amazing strides over the last quarter century and should continue to do so over the next quarter century.

Still nothing doing from Wednesday clipper and the overall forecast appears free of accumulating snow for the duration of the week. Temperatures will remain within few degrees of seasonable levels and visibility should stay pretty good given the season. Not one, but two updates ago we had discussed  a potential southern branch feature becoming our next significant weather feature. In the last update I squashed this storm as it looked "squashed" by several different computer models yielding hardly a dent anywhere on the East Coast. As of Tuesday afternoon, this system looks far less "squashed" again. It is rising to prevalence out of the ashes and is expected to leave a mark on coastal areas. For most the storm will bring rain which might change to snow as the storm exits. If the storm continues to appear stronger and farter north and west with an expected storm track, I will get very excited for Sunday. As of now it is still a whiff. It is also killing the potential clipper I had advertised as the cause for some light snow Saturday. Lets just hope for one or the other.

The overall long wave pattern will become extremely amplified as this storm departs Sunday. It will become this way without the overwhelming weight of the Polar Jet which means the East Cost will be a "powder keg" of sorts. Indeed, the next clipper which is expected to begin its approach late Monday could very well explode into something of great significance Tuesday in this set up and will warrant a close watch over the next few days. We could see ideas  with the Sunday storm and this potential Tuesday storm shift as models refine the forecast and digest the various ingredients associated with all these players. It will turn chilly later Tuesday into the middle of the week and we should see more polar jet energy by late in the week bring a reinforcing blast of potentially even colder temperatures.

The polar jet is then expected to recede just slightly into early February as we lose some support from the NAO but not enough I think to completely eliminate the cold or pose a significant risk for a thaw. The biggest upper air feature in the Northern Hemisphere by early February will be a large blocking ridge which is expected to settle in the Bering Sea. This means the Polar Jet moves south but should focus the arctic air on the western US. Jet energy undercutting this ridge in the Pacific should provide some energy for 1 or 2 well organized storm systems in early February. No reason to think that something big can't happen in this period but we will just have to wait for anything concrete to show its face.

Sunday, January 18, 2015

Green Mountains should come out on top by Monday morning

Yes indeed ! #Sweetspot. This was a tough victory to earn as well since it will be such a narrow window of good snow associated with this storm. The Adirondacks are west of the good moisture and most of New Hampshire will see rain. The Pats game in Foxboro is obviously just wet or damp (Take it easy on me Bill Belichick)  with temps in the 40's. Most of VT is sitting pretty however. Perhaps not the Connecticut River Valley and perhaps not the Champlain Valley either. The spine of the Green Mountains ? That is exactly where I would want to be !

Snow should arrive a few hours prior to the Pats Colts Sunday. There has been freezing rain and rain reported throughout southern New England and the New York City metro and precipitation could start as a mix of freezing rain, sleet and snow. There is a lot of very good moisture associated with this system and as the precipitation intensifies Sunday evening we should see more in the way of snow and less in the way of about everything else. Later Sunday night, temperatures will drop, the snow should continue to fall in the more powdery variety and should accumulate 8-14 inches on the hill by first tracks time on MLK day. Snow should continue in lighter fashion for a good chunk of Monday with temperatures in the high 20's. Elevation will be a big help during this storm. You may not do too well below 1000 feet if that's where you reside. I would expect the high country does pretty well in the end however even if things start out a little wet this evening.

Seasonable temperatures follow for the middle part of the upcoming week. A clipper passes well to the region's south on Wednesday but MRG will stay high and for the most part dry during this event.  A big, jet stream phasing, late week 2 footer is out the window I am sorry to report as of today but overall longwave pattern is going to reconfigure itself quite favorably beginning the weekend of the 24th and MRG will reap the benefits of this with several potential smaller events and a chance for a bigger one with a little good fortune. I feel relatively confident about the mountain securing 3-6 inches of powder from a clipper system on Saturday the 24th. Another system early in the last week of January should at least provide lighter accumulation. This one could grab some limited southern branch energy and evolve into something bigger though it's certainly way too early to tell for sure.

The pattern amplifies around the 27th and 28th allowing for some very chilly air to cover a good part of eastern North America. This happens as western North America completely dries out thanks to the establishment of a large ridge in the jet stream. There have been varying indications of snow events in the last several days of January and with the Polar Jet re-asserting itself, I think most of these events would be garden variety but it will still be a nice way to finish out the month and a good way to start February.

Thursday, January 15, 2015

Lots to discuss again which is good thing including two potential storms and one not so far off !

Lots to talk about once again in this ever evolving weather scenario. I think we had a bit of a better handle on things during the last update but it's time to expand on details in what should an exciting finish to January. A moisture-starved clipper system spreads its limited moisture into the region Friday resulting in some occasional light snow and a very light accumulation. This system, however, brings with it a classic New England arctic sneak attack. These particular intrusions of cold are unmodified by the Great Lakes and are thus quite vicious and often poorly identified on the medium range models. Cold will arrive later Friday and send temperatures on the mountain plummeting to near -15 on the mountain by Saturday morning. Limited sunshine during the day Saturday and lighter winds will make the day feel somewhat more comfortable as temperatures recover to above zero.

We then turn our attention to a stronger clipper system which is expected to pass through the Great Lakes Saturday night into early Sunday. As it does so it will grab ahold of a very weak but very important southern branch jet disturbance. These two systems will gradually phase with the southern branch feature using the jet dynamics from the clipper to expand its field of precipitation. There is dissention amongst the available model data on the exact track of this storm around New England. It isn't a big disagreement but the window of heavy precipitation associated with this storm, although significant, is very narrow and thus a difference of 100 miles in the storm track has a large bearing on the eventual results for our beloved mountain. The last Euro model tracked the developing system over New Hampshire with its ensemble members showing a track closer to the seacoast. Either of these scenarios deliver 10-inch hit for most of VT Sunday and Sunday night with additional snows Monday. Both the American and Canadian models were just off the coast with the track and given this aforementioned narrow band of snowfall being indicated with this storm, the result given this scenario would be a light accumulation. A blend of the results and the mountain would be on the edge, but should do ok. My guess right now is that it's about 40 percent for a 10-plus inch snow late Sunday, Sunday night and Monday and a 70 percent chance for at least a few inches. Just to clarify, the snow would arrive on a milder Sunday and should begin falling with temperatures in the high 20's. If we can land in the sweet spot, the snow would continue Sunday night and taper to lighter but continuous snows Monday.

Seasonable temperatures follow in the wake of this system later Monday into Tuesday. By later in the day Tuesday a clipper system passes to the region's south and brings most of its limited moisture well to the regions south. I don't think we are going to miss too much out of this guy. More seasonable but relatively dry weather continues for Wednesday and then into early Thursday.

This brings us to the end of the week and the re-ignition (at least we hope) of the all important southern branch. Believe me, I would throw a housewarming party for it if I could ! Over the last two days, we have seen with better clarity, indications of a significant weather system exiting the Southern Rockies during the middle of next week and gather substantial amounts of moisture as it crosses into Texas and begins to head east or northeast. Plenty of differing scenarios with what looks to be a storm exhibiting lots of potential. None of the models have yet to yield any consistent results regarding a possible outcome, but they are suggesting an outcome which in and of itself is important. If we were to get a hit out of this it would be Friday Jan 23 and would include some significant snowfall. There is certainly a chance for a miss and there is a slight chance of snow and ice (The Euro had that this morning but was farther south on the afternoon run).

Every indication is then pointing toward the development of a massive upper ridge building across western North America and ultimately expanding into the Yukon, Alaska and into the Bering Sea. This is the kind of pattern we more or less expected at the beginning of the winter and we should get a good dose of it for at least the last week of January. This means the re-arrival of the polar jet, the southward advance of the "Polar Vortex", lots of cold air, and a few clippers to go along with it. The Euro Ensembles showed a result  liked the best that included the continued presence of the southern branch of the jet stream, especially toward the very end of January. Lots of good things here, enough that we can handle a bad surprise should one show up at the last second.

Tuesday, January 13, 2015

Snowier forecasts and squashed warm-ups - These are a few of my favorite things !

Lots to discuss today as the expected weather map going forward is taking on a fundamentally different look, particularly in the period beginning MLK day and persisting through a good chunk of next week. This is simply one of those days where guys like me look at the Chess Board and come to the realization that its time to wipe the slate clean and start anew. In one of our recent discussions, we talked about, to put it kindly, the erratic performance of some of the medium range ensembles this winter. Specifically as it relates to the weather beyond a week out. The rapidly evolving weather scenario for next week is underscoring this point. I mean even the larger scale ideas that were advertised with vigor only a few days ago have been thrown completely out the window today. There are reasons for this and opinions will vary as to those reasons. Generally speaking, many of the super-warm ideas that have been indicated on some of the long range weather maps have failed due to feedbacks related to that big expansion of snow and ice that we saw leading up the winter. There is simply a lot of cold air that has pooled at the high latitudes and it is fighting hard to move south in spite of whatever weather pattern is present. The Pacific Decadal Oscillation has soared to near record positive levels making it very difficult to position any type of upper ridge across eastern North America for any significant length of time, even when the ensembles suggest as much. And lastly, the presence and absence of the southern branch of the jet has wreaked havoc on the longer range ensembles. The positions of even subtle "ridges" and "trough's" in the southern branch can have a profound impact on the evolution of the pattern. It's really just chaos theory. If you integrate through time and get something significantly wrong 5 days out, even something seemingly subtle, the dominos start to fall and errors magnify exponentially 10 days out.

But none of us should be complaining in this case since the changes should, by in large, benefit our beloved Mad River Glen skiing community. Maybe even those that planned to venture up on the upcoming long holiday weekend and plan to ski on what looked to be a quiet and possibly even mild MLK Day.

So lets get to it. The short run looks dry and on the chilly side. Sub-zero temperatures during each of both Wednesday and Thursday morning will get boosted into the teens Wednesday and 20's Thursday by healthy dose of sunshine. A weak clipper Thursday night, passing well to the region's north will spread some limited moisture and very light snow to the mountain and an inch or two of accumulation by early Friday. Blustery conditions prevail for the duration of Friday and those winds will introduce another night of sub-zero temperatures.

Saturday appears on the chilly side but free of snow. There were hints that some overrunning moisture associated with a push of warmer temperatures might impact the mountain and this will occur but much farther north. Clouds will then increase Saturday night in advance of another, much stronger, clipper system. This particular piece of energy might be capable of grabbing some southern stream moisture as it heads toward the eastern seaboard. If this does indeed occur, the system is expected refocus itself along the coast and intensify Sunday. From there, the system will either head out over the ocean or remain close enough to the coast to spread rain along the coast and snow in some of the elevated interior areas such as MRG. Either scenario means some snow for the mountain Sunday night into Monday since we will either get it from the decaying clipper (a light accumulation) or more from the rapidly intensifying coastal system. All this is a very welcome change from a scenario which was shaping up to have this clipper pass well to our north and potentially spreading mild above-freezing temperatures into the region late Sunday into Monday. In a day or two, I'll have a better idea as to amounts of snow when we know for sure whether or not this storm will come to fruition.

The later part of MLK days into Tuesday Jan 20 looks substantially colder with temperatures only the teens by day and sub-zero by night. This was in a period where the ensembles advertised a potential thaw maybe 3-4 days ago. The other big change involves the southern branch of the stream which continues to look dormant. It is the only real piece of semi-lousy news I could come up with today. We simply can not seem to re-ignite this branch of the jet since it went quiet in late December. Perhaps a slight weakening of the current El Nino has allowed southern stream energy to be less prevalent but I hope to see more activity in the future. The combination however of a much weaker ridge across eastern Canada next week and the apparent continued absence of the southern branch of the jet stream gives the middle to end of the weak a much different look. There are indications of a weather system in the mid-week period (Jan 21-22) but a much weaker one and the good news, a much snowier one since warm-up has been squashed in successive recent runs of model data.

Looking beyond the 22nd, the teleconnection support gets a little better, mainly since the positive NAO will be reduced while PNA ridging in western North America is maintained. We are expected to see a small tightening in the jet stream however which could throw a couple of strong storms into the Pacific Northwest around the time of January 24th-25th. I would expect at least some arctic air to be battling it out with these storms in the last week of January. This feels more like a guess right now given how poorly some of these longer range simulations have performed in the last month or so.

Monday, January 12, 2015

Nothing big for MLK weekend but I could have worse news

Some light snow here and an occasional snow squall there and very gradually we are regaining a bit of softness on the hill. The additional snow on Monday will help in this regard. We should receive 3-5 inches or so before it again turns very chilly. Tuesday, Wednesday and Thursday will all be dry and should feature a decent amount of sunshine. Both Tuesday and Wednesday will feature sub-zero temperatures in the morning and teens in the afternoon. Thursday should be a little less cold with readings climbing into the 20's.

Unfortunately, I think we have to put the potential late-week and pre-holiday nor'easter to bed. The southern branch system is not displaying the kind of prevalence we need. In addition to that, lingering polar jet energy will prevent any such system from any type of New England impact. A weak clipper system Friday associated with this polar jet could provide another small accumulation followed by a chilly day Saturday.

The period beginning Sunday Jan 18 and ending Thursday Jan 22 is the time frame where the mountain could be under siege from milder temperatures. Without the support of any of the major teleconnection indices combined with strengthening jet in the Pacific means without a doubt some above freezing temperatures. The question is whether this particular setup results in a major and damaging thaw or whether the damage can be limited and a more productive alternative can be found. Some of the most recent information suggests the latter. The southern branch will rediscover itself and a storm will move into Texas and then advance toward the eastern seaboard by about the time of Jan 21. A very limited supply of cold air will be available but perhaps just enough to keep us in the game and provide us with a puncher's chance at something other than plain rain.

I did skip over some important details on MLK weekend. The chilly day Saturday could be followed by yet another round of light snow either late in the day or early Sunday. Sunday and Monday could feature temperatures in the 30's but overnights should remain below freezing. We then focus on the potential storm which still could turn into at least a brief thaw.

There are signs on recent the last few ensemble runs of more support from the PNA and AO after the 22nd. There is some major disagreement between the European and American ensemble about personality of the Pacific jet and how it might impact the pattern across North America but I am marginally confident that the month will finish on the colder side. The key is to get through the storm on the 21st and 22nd without a damaging thaw (and perhaps get some snow in the process) and we should be off to the races from there.

Thursday, January 8, 2015

Lots of light snow over the next 4 days, big storm for late next week is still possible but not likely

Not much new to report either in the short range where we're still expecting a small dose of snow and in the longer range, specifically in the days before and during the MLK holiday weekend when we may or may not get impacted by a storm.

The clipper system is rotating through the Great Lakes quite quickly. It will spread it's snow into Vermont by early Friday. The snow will be fluffy and won't be particularly heavy but could accumulate 2-4 inches on the hill. A nice reinforcing blast of chill then arrives on Saturday and there is the weakest of impulses within the polar jet which will help guide lake effect moisture and some added Lake Champlain moisture on to the mountain. This might allow for another inch or two Saturday. All very much needed and appreciated. Saturday's set-up is unique and I wouldn't be surprised if someone gets lucky and surprises with 5-plus inches. It will continue to be on the chilly side through Saturday though not as cold as what it was Thursday.  Expect temperatures to sneak into the 20's Friday and remain in the teens Saturday

On Sunday, temperatures will moderate out of the bone chilling cold. This means that much of interior New England will become enveloped by warm advection. This can mean some overrunning snows though models disagree on how much of that we might receive late Sunday into Monday. At the very least however we should get another small dose (1-3 inches) by late in the day Monday. The information today suggests we dry out for Tuesday and Wednesday as chilly yet not brutally cold air settles into the region.

It would be very nice if we could successfully spin up this pre-MLK day storm. There is lots of baroclinicity across the southeast. This means a healthy clashing of airmasses and lots of frontogenetics. And the preceding two sentences has way too many ridiculously long words (sorry about that). As this is happening the pattern is expected to amplify and do so thanks to a noticeable southern branch feature. The Euro on Wednesday produced a beautiful looking storm out of all these ingredients but we have yet to see any consistency in the output or support from some of the other medium range simulation. At this point a big hit for Vermont is probably less than 50 percent but I think a hit for somewhere in New England is greater than 50 percent.

The polar jet recedes further for the holiday weekend and temperatures will slowly but noticeably moderate. We could begin seeing some above-freezing temperatures toward the end of the holiday weekend and especially by the 20th of the month. This doesn't necessarily mean a catastrophic thaw but it does mean a series of above average temperature days. The southern branch of the jet is expected to remain active and could produce another significant precipitation producer around the time of Jan 21.

Tuesday, January 6, 2015

Snowfall only expected in small increments in the coming week

Although the region has been one of the few across the country to maintain some snow through the recent two weeks, we are in some serious need of some new snow. We have a little coming our way and there are hints of a few possibilities out on the horizon but nothing of huge significance through the upcoming weekend. The clipper system we had hoped would deposit a few inches on the region moved well to the south and brought snow to Washington DC (I don't like it when they get snow and we don't !). Still there is another disturbance moving quickly through the polar jet and we should see a quick burst of some snowfall with the added terrain and Lake Champlain enhancement. It won't amount to more than 1-3 inches before brutally cold weather settles on the mountain later Wednesday and persisting through early Friday.

Another clipper should then impact the region during the day Friday. The polar jet will be lifting a bit at this point allowing some of this system's moisture to take more direct aim at the region. This is another very benign system so I would be hesitant to say anything more than 2-4 inches but these little nickle and dimers should help soften the mountain up a little. The rest of the weekend will be primarily dry and relatively seasonable. This means single digits for lows, 20's for high's and not too much in the way of wind.

Still expecting the pattern to soften next week. The polar jet will recede but the upper ridge in the jet stream will remain in the west. This could have been a very interesting week if the southern branch of the jet stream came out to play but there are simply no indications of this yet. There is another clipper system Monday and a possible jet amplification late in the week. This particular period, Jan 14-16, still looks intriguing but we need to get some moisture from somewhere and models are just not showing it right now. I am keeping my fingers crossed and still think we could see some changes, especially considering how inaccurate some of the medium range computer simulations have been beyond 10 days.

Speaking of that, we can take an early look at the MLK holiday weekend. Right now I can't promise much help from any of the teleconnection indices and the upper ridge across the west is expected to dissapate somewhat. This allowing the ensembles to show a very warm signal between the 19th and 22nd of the month. The only saving grace is the indication of some long awaited help from the southern branch of the jet stream, but unless some of these fundamentals turn around we will be lacking for cold air. Again, models have struggled this year beyond 10 days so I would expect opinions to evolve over time. 

Saturday, January 3, 2015

Another layer of concrete solidifies the base prior to a wintry week

Nice swath of moderate to heavy precipitation of many varieties has impacted much of New York state Saturday. This stuff will all move into Vermont as snow Saturday evening and all of the latest and greatest information available suggests a nice little thumping in a window between 6 pm and midnight Sunday. There is no way of avoiding a dramatic rise in temperatures that is expected above 5,000 feet after midnight. This should change precipitation to a sleet and freezing rain mixture. The question then becomes whether or not the warmth can mix its way to the surface by early Sunday allowing precipitation to be all rain. My guess is that a few hours of rain does occur with temps reaching the high 30's Sunday. This after 4-8 inches of snow and sleet Saturday night. After it turns dramatically colder by Monday morning, the frozen conglomeration on the ground will just be another foundation layer.

After a mostly dry and chilly Monday, clouds will advance back into the state Tuesday and moisture from the approaching clipper system will begin falling as snow during the afternoon. Still some mixed indications from the model on where the best plume of limited moisture sets up Tuesday but my guess is that it is south of MRG. The storm will eventually gather some strength but in all likelihood this will occur a few hours too late. What we should see is a nice combination of Lake Champlain induced and terrain induced snow showers Tuesday night into Wednesday. The contributions of both the clipper system and the lake/terrain induced snows should amount to another 4-8 inches. This snow will be much fluffier than the concrete underneath. It will turn brutally cold late Wednesday with temperatures falling to sub -10 Thursday morning. Temperatures will moderate a little by Friday afternoon (perhaps back into the teens) before another clipper provides another refreshing dose of light snow prior to the weekend of the 10th and 11th.

In the prior post we discussed the expected "softening" of the pattern which is expected to occur after Jan 10. There is little doubt that this will happen but I've become more confident of a productive softening. We lose the support of the Arctic Oscillation and the North Atlantic Oscillation and much of the high latitude blocking is expected to vanish. Still, there remains support to keep the mean ridge in the Jet Stream over western North America, keeping the door open for some excitement and reducing the risk of a thaw. The pattern is in fact a setup very typical in an El Nino winter. If the southern branch of the jet stream can produce a system or two, we will be off to the races for the middle of Jan.

Thursday, January 1, 2015

Weekend storm consists of snow ice and even a little rain Sunday

I know many are waiting for the needed"refluffing" but the mountain has remained open and although the expert terrain has some technically challenging conditions, if you conquer that stuff you can about conquer to the world. I was hoping our weekend event would result in some old fashion dense "atlantic powder". We certainly have the cold air but unfortunately it does not seem in the cards. The storm will ultimately track up through the St. Lawrence Valley and thus bring it's push of mid-layer tropospheric warmth into most of Vermont by early Sunday. Still, we still should get a nice burst of moderate to heavy snow Saturday night as a healthy plume of moisture moves into New England. If all goes according to plan, the mountain could receive 3-6 inches before precipitation changes to sleet and freezing rain in the very early morning hours Sunday. Temperatures will then creep closer to the freezing mark and perhaps even exceed the freezing mark for a few hours Sunday. The ski day Sunday will therefore not be a powderfest but should have some new frozen precipitation to ski in. Overall Sunday will be a little damp and slushy before much colder weather moves in Sunday Night.

We can still look forward to a very wintry week following the mild Sunday. Monday will feature temperatures in the teen along with some snow flurries. Tuesday should then start in cold and tranquil fashion with sub-zero temps but clouds will advance into the region from a somewhat disorganized clipper system and some snow should overspread the region by the evening. If this particular system, a pure polar jet product, can get it's act together a little and have a constructive interaction with the Atlantic Coast it might provide the mountain with some significant snows. Right now though it looks like a light accumulation Tuesday night. Terrain induced snow showers and snow squalls should impact the region Wednesday. An unfrozen Lake Champlain will make a contribution as well and should allow for a burst of snow before temperatures turn extremely cold Wednesday night. By Thursday, readings will be in the -10 to -20 range along with some blustery northwest winds. The extreme cold continues through Friday morning before temperatures moderate slightly. By late Friday the next weak weather system could spread some light snow or flurries into the region.

There are some strong indications in the longer range that the pattern will "soften" following the outbreak of extreme cold late this week. This means that the polar jet will again recede and the threat for extreme cold in the period between the 10th and 20th of January is minimal. Does this mean another thaw however ? There have been a few hints of here and there but no resounding indications as of yet. With the help of the southern branch of the jet and even small amounts of arctic or even just Canadian air, a soft January pattern can be productive. We are not expecting a huge tightening of the jet stream in the Pacific and although the NAO is unlikely to provide much cooperation during the middle of the month, there are also signals of some ridging along the west coast. This would help keep the overall pattern "honest" for January as opposed to an all out thaw. The key in my view is the southern branch. We need some help from this segment of the jet stream which has quieted a little in the last week to 10 days and should remain quiet through our upcoming cold week.