Late December Christmas outlook - lots to cover !!

We have one solid blanketing of snow and a memorable opening day in the books at MRG, but time keeps on ticking into the future and there is a lot to contend with in this future. The first half of this December is one of the coldest starts to the month we have seen in a decade and the cold has occurred in spite of a pattern not entirely supportive of sustained cold or big snow. The prevailing upper air feature in the jet stream has been a blocking ridge in the Bering Sea. This is hardly the ideal position for such a feature but it nonetheless sent such an onslaught of arctic cold into North America that the pattern was more or less overwhelmed with cold much like it was in my favorite winter of 1993-1994. It is such an encouraging sign going forward (at least this winter) to witness arctic cold battle the prevailing pattern with this type of ferocity. In spite of this, we still have to deal with some of the variability that such a pattern was inevitably going to produce. 

We will see this variability manifest itself during the upcoming weekend but in the meantime there is plenty of cold air in place and an incoming clipper system that promises to bring some light snow to the Green Mountains later Tuesday. Light snow from Tuesday afternoon into the evening might amount to a very fluffy 2-5 inches, enough for a few fresh turns Wednesday but the density of this snow will be noticeably less than the almost 2 feet of snow already on the ground. This particular clipper system will have its energy swallowed by a developing coastal system which promises to bring eastern Maine some nice powder Wednesday. Mad River Glen might see some snow showers or at least flurries Wednesday and some more lighter snows Thursday as a boundary representing the warm push of air makes its way toward VT. I don't expect much in the way of accumulation after Tuesday night. 

This brings us to Friday and the weekend which could feature all kinds of weather, possibly lots of weather and as of yet medium range models have failed to develop any sort of believable consensus. We do know that the northern half of our Bering Sea ridge will get chopped off leaving a pattern closely resembling that of the dreaded "evil empire". This being a upper ridge in the mid-latitude Pacific. Lots of mild air will thus make it's way northward, particularly Friday and although some of the aging arctic cold in eastern Canada will fight for control of interior New England, it could get dicey for sure. At this point it seems like there will be an initial push of warm air which will reach parts of VT for Friday. Parts of the mountain could see several hours of above freezing temperatures and perhaps some rain or freezing rain although precipitation on this day appears to be minimal. Colder temperatures will make a rather feeble push south Saturday ahead of what could be a very powerful storm system which will gather strength in Texas Saturday and head in our direction. In this particular situation, it will prove very difficult for this weak area of cold to play defense against a storm heading for the St Lawrence Valley. That being said there are hints on the last round of model output that the storm will travel south of Canada and perhaps right over Vermont allowing the cold weather, at least at the surface, to maintain a precarious grip on the region. There will be copious amounts of moisture sent in our direction and precipitation Sunday is unlikely to be snow but rather sleet, freezing rain or just plain rain. A significant icing event is actually possible in such a set-up but hard to pinpoint for sure how possible as of now. If we do get accumulating snow out of this storm, it would be Sunday night or early Monday. 

This brings us to the all important Christmas week which has yet to get extensive coverage from SCWB (it  has been overshadowed by our recent storm). A somewhat moderated arctic air mass should envelop the region in the wake of our big weekend weather producer. The ensembles however seem to be keying in on another weaker push of warmth around Christmas day. The American ensemble package has been downplaying this repeatedly and has suggested a relatively normal week of weather with a chance for some of the white stuff around Christmas day as opposed to any milder temperatures. I hope the American is right but another mild day and maybe another rain/ice event is possible around Christmas day. I would be more confident of a more serious push of cold weather and possibly some snow in the days following Christmas and into that last weekend of December.  

What a nice looking December winter storm !!

Opening day is upon us in what looks to be a very promising start to the season. Even the Champlain induced, terrain induced snow shower machine has chimed in with some help this week in front of one of the better early season storms we have seen in VT in a few years. Yes we have seen some stronger storms and this one shouldn't become part of any New England folklore; but nonetheless, this is a beautiful noreaster for us. The track of this storm will ultimately be right over Cape Cod, the ideal scenario for the MRG powder freaks such as myself and many others. Snow will begin Saturday evening and some very intense snow is possible between midnight and dawn Sunday. This is a fast moving system that should make it's way into the Gulf of Maine by midday Sunday and the snow should taper to flurries by the early afternoon. In the last few days it actually has been quite unnecessary to provide updates. Last Monday it looked like we could get a 1-2 footer and it looks like that now, 1-2 feet of noreaster powder, and hopefully a critical part of the MRG base for weeks to come this season. 

I want to provide a more detailed update on what we might expect for the Christmas holiday, seeing as the ski season will be in full swing and I will do so tomorrow. In the shorter term however, there is a nice little follow-up to the weekend storm that will arrive later Tuesday in the form of a clipper system. This system represents a fight between arctic air and pacific air, both competing for control of eastern North America. The result should be some fluffy snow Tuesday and Tuesday night and some additional powder for the Wednesday ski day. We still have at least one and maybe two pushes of warm air to deal with in the weekend prior to Christmas. We can talk about that tomorrow but for now enjoy the storm, its a beauty. 

Storm musings and the weather in the week that follows

Winter is blooming at Mad River Glen. Cold temperatures, snow showers and squalls has the MRG community itching for opening day. The only thing that might be better is some big storm excitement and it just so happens that we have some of that as well. We can't ask for a much better set up either. We have a reenforcing fresh short of arctic chill clashing with a viable southern branch system. The Low pressure system will strengthen in the Ohio Valley and make the jump to the southern New England coast, ultimately moving in the near vicinity of Cape Cod before exiting into the open Atlantic. Snow from this system will arrive Saturday evening and persist through midday Sunday with the heaviest snow likely falling in the pre-dawn hours Sunday. If there was a trend in the cycle of model runs today it was that the storm has a somewhat flatter and weaker appearance. The last American model released Wednesday evening strengthened the storm to a shade under 1000 mb while the European model Tuesday showed a storm close to 980 mb walloping Vermont with 2 feet of snow. This somewhat fickle behavior in the models is very typical a few days from the storm and is a big reason to not sell your soul to the snowiest model. At face value, models today showed a modest 8-12 inch event with some of the heaviest snow falling falling across southern Vermont, the Berkshires and much of New Hampshire. I would not sell my soul to this solution either, at least not yet. It is still possible to get a stronger storm and upwards of 20 inch snowfall totals. Stay tuned !!

The amplification in the jet stream associated with the weekend storm will help keep temperatures on the chilly side of average through about Tuesday or Wednesday. After that, things could get really crazy. If you have been following the blog at all at this early date in the season, we had discussed the Bering Sea upper ridge and its tendency to produce volatile weather across the eastern U.S. including wild swings in temperatures from warm to cold and vice versa. As we move toward late next week, we could be faced with just such a scenario. The jet stream will again amplify but do so over the western and central part of North America thus sending a huge surge of warm temperatures up the eastern seaboard. Arctic air will try to fend off a chunk of this warm push late next week and next weekend (12/21 and 12/22 ) but this could evolve into a thaw or an ice storm or a rain to ice to snow situation. After our big storm, I am hoping for none of the above honestly and maybe we can find a way out of all those scenarios. Time will tell. This battle between some warmth along the eastern seaboard and arctic cold over Canada should continue into Christmas week and could result in a noteworthy event near the Christmas holiday.

More details on potential weekend storm !

I wasn't going to do any detailed update but with the MRG opening bell nearing and the weather this weekend "evolving", a brief one is warranted. On sunday we had discussed the possibility of snow on Sunday before more arctic chill encompasses the region early next week. The situation is a bit more intriguing however since a split in the jet stream and southern branch energy will be capable of incorporating more moisture into the equation. The last 1 or 2 cycles of models have clarified somewhat  the "if", the "when" and the "how" regarding the phasing of this system. And yes, we absolutely want this system to phase, we want it to phase a little earlier and we ultimately want a coastal low to absorb the systems energy off the New England coast. Although this is not etched in stone, it was certainly the trend in some of the last few bits of information. This system has a lot of the right ingredients to be a big snow producer, one certainly capable of getting winter mountain activities up and running.

Precipitation, we hope snow, would arrive late Saturday evening and persist through much of Sunday. More cold air then invades for Monday. Snowfall totals ? A bit too early for that speculation but we should at least up the range of expected snowfall for the next 7 days which should include some snow from snow showers and snow squalls Wednesday.

Much improved expectations for the middle of December

The first potential decent winter storm deposited much of its snow on southern Pennsylvania and managed largely fizzle as its depleted moisture overspread Vermont. Still, the limited snow provides the setting for a wintry scene which will prevail through much of this week and even into early next week. There is little doubt in my mind that the ferocity and expansiveness of the arctic chill so far this winter has been impressive, specifically how the arctic cold has managed to defy some of the less than optimal upper air configurations. It is vital to note that this is a very empirical observation yet an important one that must invariably be incorporated into our medium and long term expectations. In spite of the fact that the pattern has yet to favor cold or snow of any real magnitude over New England, it has favored cold and snow across the central and western United States and the result has been widespread areas of 20-25 degree below normal temperatures. We actually haven't seen much of this the last few years; in fact, we probably have to go back to 2003-2004 or maybe even prior to that since we have seen cold weather of that magnitude in the United States. Needless to say, when the pattern does align itself for cold across the northeast, the cold weather is likely to be considerably more intense than anything we have seen in the recent decade or so.

In the near term and specifically over the next week, we are actually set up for some very chilly December temperatures. A wave of low pressure will bring some mixed precipitation to coastal areas of New England Tuesday but will mostly miss interior areas like the Green and White Mountains of Vermont and New Hampshire.  On Wednesday, the Polar Vortex will take aim at New England and upper level impulse marking the leading edge of this surge of arctic chill should spread snow showers and a few snow squalls to the high country Wednesday and Wednesday night. It then turns bitterly cold by Thursday morning and this chill persists through Friday before modifying slightly before the weekend.

The "slightly" part of the last sentence is noteworthy since we had expressed some concern about a big warm-up for the middle of the month or maybe even a ugly pre-holiday thaw. Ensembles over the last two days have suggested that is much less likely which marks a big shift in the medium range guidance and certainly changes some of my expectations in the important week leading up to Christmas.  A reenforcing shot of arctic air is expected in the latter part of next weekend and this may or may not be accompanied by some snow. The European model is actually hinting at a significant snow producer for the Mid Atlantic while the American and Canadian model packages of hinted at a light to moderate snow event for the likes of us. I no longer expect a big move toward above normal temperatures after the 15th of the month and instead expect normal and even a few days of below normal temperatures with 1 or 2 chances for snow. This is a big improvement and some very good news in spite of the disappointing results from our Sunday Night-Monday event.

Widespread snow/sleet event for Monday will be part of a very wintry week

Our first significant widespread snow event across the northern part of Vermont will arrive Sunday night or Monday morning. This will be one small part of a very volatile temperature forecast over the next two weeks. The pattern is being anchored by a giant omega blocking ridge over the Bering Sea. This is sending plenty of strong arctic air southward, but most of it is going into the Plains and Rocky Mountains where many spots will see temperatures near record levels during the coming week. Some of this arctic air will move eastward but we will not be the focal point of cold in this pattern. 

We are set up to have a somewhat wintry upcoming week however beginning over the weekend when the first batch of arctic cold displaces the mild air that will dominate the region Thursday into early Friday. A dusting to as much as two inches of snow is possible by Saturday morning but the real system of note is a loose conglomeration of low pressure centers which will gradually move out of the Rocky Mountains later this weekend. Arctic cold will be well entrenched as this system approaches. One of the systems two centers will move toward the eastern Great Lakes while another cranks up along the Atlantic coast. This is a very garden variety storm but it will impact a broad area of interior New England with snow across both mountains and valley locations. Snow should arrive late Sunday evening or early Monday with the heaviest snow lasting not more than a few hours. Precipitation could end as some sleet or freezing rain later Monday. I would put this in the category of a 6-12 inch event with the mixed precipitation adding some density or possibly some crust to whatever falls. Quite possibly a good base-building event !

Another batch of the some of the intense cold centered across western North America will then build across the region during the middle of next week but will likely be rather short-lived. The Polar Vortex could actually get rather close to Vermont for a day or so, perhaps sending temperatures well below zero for the first time this winter season. A clipper system could add a light accumulation of snow to the region as well. The Bering Sea ridge and the lack of any downstream blocking in the Davis Straits or Greenland will allow the cold to escape rather quickly and this could set the stage for another mild week beginning around the 14th or 15th of December. A few days ago I was more concerned about a widespread outbreak of mild temperatures but I think lingering cold in Canada will compete for control of the weather in spite of the overall expected jet stream configuration. At the very least however, it is likely we see some more above freezing days in the week preceding the Christmas holiday. 

Variable pattern to dominate first half of December

The big finale to November has many giddy about the upcoming month and why not, it has been a momentous week to ten days. In reality though, the first half of December is typically erratic and more recently a big struggle. This one appears that it will conform to this norm since in spite of some promising looking possibilities in isolated parts of the forecast period, the next two weeks as a whole is fraught with trouble.

Arctic cold still, as we speak, encompasses much of Canada and is helping to rapidly freeze the Hudson Bay (now ~ 60 percent frozen). Unfortunately, it's influence has someone subsided across New England and points south. Were it to be more pronounced, a developing coastal system Tuesday might have had a greater chance of manifesting itself into something significant. As it is, the system will develop and it will mainly be a mixed rain and snow producer for coastal New England, exiting the region Tuesday evening. The duration of the week will generally be free of any new snow. Arctic cold and snow will descend on the Rocky Mountain region while the east coast will see a warming trend. Precipitation, if it falls at all, will be rain Thursday night (although nothing more than a period of a few hours).

Speaking fundamentally, the pattern in front of us is being anchored by a strong blocking ridge in the Bering Sea. Blocking, in general is a positive thing and the jet stream in the Pacific will be "loose" as opposed to "tight" which is also a positive thing. Longitudinally speaking however, the Bering Sea blocking ridge still presents some problems since it is a mechanism for focusing cold on the western half of North America while there is no mechanism to hold the cold in place over New England or eastern North America. The result is a highly variable pattern with intrusions of cold, some significant followed by quick warm-ups. New snow, maybe even a significant snow is possible as well but a thaw might quickly follow.

After a day or two of above freezing temperatures later this week, there will the first move toward colder temperatures by the weekend but this turn to colder weather does not look like it will accompanied by any snow. The next best chance for good snow comes around the 9th or 10th of the month as a potential system exits the Rocky Mountain and gets catapulted northeastward toward the eastern Great Lakes by another big jet amplification across the west. Actually, the track of this system is still very much in question and if the amplification across the west is a bit more imperfect, it might generate a flatter system. The snowiest solution would probably involve some compromise of the above solutions. The potential storm (or no storm) will be followed by a more significant chunk of cold for the middle of the week but this to will be short-lived. By the 13th of the month there is some strong evidence to suggest a more significant push of warmer temperatures, perhaps even a significant thaw since the Bering Sea ridge may in face bottle up much of the cold in western Canada or at least that is what some of the ensembles are indicating.