Thursday's potential snow and lots of other ramblings to end 2013

I've been waiting and hoping that the information out there would converge into something very big for the mountain Thursday. Unfortunately, for our late week storm, the consensus of data suggests a loose more disorganized conglomeration of low pressure centers that will push through the Ohio Valley and off the east coast before intensifying into anything significant. I throw the word "phasing" the blog like I would throw a frisbee (which is a lot) but for most of our potential winter storms, the process is critical in determining whether we are "in" or "out" of the best powder. I like to think of phasing as the jet stream and the weather at the surface achieving a perfect harmony like a Jerry Garcia with his electric guitar and Phil Lesh on bass (I think Phil would be the Jet Stream and Jerry might be the winter storm). Phasing occurs quite often in New England because many of the necessary ingredients are always present such as jet stream energy, the accessibility of moisture and the ambient clashing between cold dry arctic air and a relative warm moist Atlantic Ocean. The best storms in Vermont phase early, but often not too early (as they did many times last year). These storms more frequently track very close to the coast or even inland and interior areas of New England are the best spots for the big snow.

The surface map is a tinderbox right now and one good injection of upper air support would mean big things for MRG and the surrounding region. Such support does come but it will come just a little later than we wanted. Snow will expand into New York State and much of New England but unless something changes, the storm will ultimately consolidate its energy off shore and pull the heaviest snowfall to the coast and eventually out to sea. Anyway, that was a lot of rambling for a paragraph and a half and in the end, WE SHOULD A POWDER DAY THURSDAY. Light snow should begin around day break and continue for a good part of the ski day. I think this is a 3-7 inch event, but when it comes to questions of phasing LOTS CAN CHANGE. The Valentine's Day Storm of 07 reached hall of fame status but was not expected to be until very late in the forecast period. Thursday and Friday will be two of the coldest days New England has seen in some time. Temperatures will be near zero all day Thursday as its snowing and below zero all day Friday. Saturday morning's temps could be near -15 F but readings should moderate to more tolerable levels by the afternoon then warm into the 20's Sunday.

Another storm is going to require our attention by late into the weekend into Monday. This is another interesting one and perhaps a storm that might phase too early. The Euro model is indicating a one of those classic "bowling ball" trough's and one for the ages as well. These types of events are dangerous for New England ski country as they send 50 degree readings north to Quebec while sub zero temperatures hit the Ozarks. This is not the consensus solution yet however as other medium range models suggest that potential "bowling ball" never achieves perfect symmetry. A partial phase and a more squashed system could mean some powder for Sunday into Monday. The Euro does bring at least a chance for rain however. The arctic cold that follows this storm could be very memorable as readings, particularly in parts of the Mississippi and Ohio Valley's get well below zero and even challenge records. We saw cold of this intensity in '09 but nothing like that since. The "evil empire" is showings its face as we move beyond January 10th although ensembles have performed horrendously so far this winter so I won't expand on any of those details until later.

Lets hope at least some of this storm pans out. Happy New Year to everyone and think powder !!

Another batch of the good stuff brewing for Thursday/Friday ?

By the time most of you will be reading this, the few inches of glop Sunday night will have turned to a somewhat windblown layer of powder. Temperatures will turn very cold so hopefully the snow consistency is good enough to be considered a powder day for those of you that venture on the mountain. The focus now has to shift very quickly to the New Years day period and another rapidly evolving weather situation in the days that follow New Years. It is amazing how fluid the weather forecasting has been this year and we should expect that to continue. It has been somewhat easier to predict temperatures relative to normal in a general sense but day-to-day weather specifics has been a challenge outside of the 5 day window. Forces the SCWB to earn its money with more frequent updates I suppose.

This will be a very cold 6-day period as has been discussed previously. Temperatures through the upcoming weekend will struggle to get above 20 at any point and we will have several mornings at or below -10 and at least 2 days with wind chills well below zero. We had hoped to get some new snow out of this very bone chilling ordeal and its looking more and more likely that this will indeed be the case. The first snow will come New Years eve from an upper air impulse that will produce some terrain enhanced snow. Snow accumulations from this will be on the order of a few inches and unlike the glob, will be a very fluffy variety. If we are lucky, we will get a somewhat powdery New Years Day.

The "BC Bomber" that has entered the equation in this very evolving weather picture arrives Thursday Jan 2. This system has been discussed but its potential before now has been somewhat underrated. Pretty much all of the major medium computer models are now on board that the system will gather some limited amounts of Gulf moisture, deepen and then strengthen rapidly off the Atlantic Coast. Models disagree with the intensity of strengthening and the track and it is this question which should now be the prevailing debating point as to how much powder actually falls Jan 2/3 at MRG. The European model is the dream scenario because it is suggesting an all out explosion south of Cape Cod and a 1-2 footer for much of Vermont. The Canadian and GFS suggest a more modest deepening with this system, a flatter system overall and confine much of the heaviest snowfall totals to coastal sections. The final answer might have to wait until New Years Day to be answered but we should at least look forward to some modest powder Thursday into Friday. Timing of course will have to be fine tuned in the next few days.

There is some additional fine tuning that is required on what appears to be shaping up to be a volatile week beginning Sunday January 5. There are some potential trouble spots, some more potentially bone chilling arctic air and maybe even some additional powder. A bit of the "all of the above" which was my favorite multiple choice answer on those old high school exams but perhaps not so much when it comes to winter weather.

Wet snow late Sunday and Sunday night will turn more powdery Monday as temperatures nosedive

Most of the current weekend will be on the cloudier side but temperatures will be rather mild for late December, achieving and exceeding the freezing mark both Saturday and Sunday. The question we all want answered though is whether or not to use that last vacation day of 2013 on Monday (or fake sick). There has been some small modifications in the thinking regarding the storm that is expected to advance up the Atlantic Coast Sunday and spread precipitation into the region Sunday afternoon but we think we have enough information to provide some detailed expectations.

Given the prevailing mild temperatures encompassing the mountain, you would be right to say that temperatures will be in that marginal category Sunday afternoon as precipitation commences. Model cross sections are in fact indicating some above freezing layers in the lower troposphere, and as a result, precipitation may begin as some rain or sleet. Within an hour or so of the precipitation start time, we should begin seeing all snow. Temperatures will hover around the freezing mark through a good part of Sunday night and the snow consistency could be a bit gloppy in low lying areas while closer to powder near the summits. In areas below 1000 feet, precipitation could remain mostly rain or simply a rain/snow mix. The snow should taper to flurries or snow showers Monday morning as the arctic deluge reaches the mountain but a few hours of heavy snow overnight should push snow totals in the 6-12 inch category. As wet as the snow might seem Monday night, plummeting temperatures during the day Monday will alter the consistency of the snow to a dense powdery layer. It will also be quite blustery creating wind chills of near zero as actual temperatures to near 10 by late in the day. 

The arctic cold will prevail through the New Years holiday and into the first full weekend of 2014. Models are not at all conclusive regarding some of the fast moving systems that might be on the weather map during much of this time frame. The American model suggests that a clipper system will rotate into the Ohio Valley around New Years Day and later intensify off the northeast coast into something fairly interesting by Jan 2nd or 3rd. The European Model keeps much of the precipitation from this system well south of the region and by the weekend has a massive coastal system near Cape Hatteras with historic snows in the Virginia Tidewater area. The Canadian model is also on the dry and cold side for interior New England. There is undoubtedly a few things that need to be sorted out. For the mountain, our best  shot at some additional snow comes late New Years eve into New Years day. We do know it will be very cold with temperatures near -10 on a few mornings between Tuesday and Friday and struggling to get above zero during the days. 

In the longer range, we still have the negative AO competing with a retrograting ridge. In summary we will go from two favorable teleconnection indices late next week to just one by around January 8th or so. This leaves us somewhat vulnerable for trouble between the 8th and 10th of the month. 

Weather in the pre - New Years Day period "evolving"

We have a bit of powder covering the frozen crust and can now look toward the end of the weekend for some more potentially good news. The weekend weather has been "evolving" and the medium range models have more or less failed to indicate with any consistency how it will all play out. We had an idea that temperatures would at some point make a run at the freezing mark and we knew that by Sunday, we had a chance for some snow from a clipper system marking the leading edge of very cold arctic air that is poised to send temperatures below zero on the mountain by New Years Eve. Things have gotten more interesting with the southern branch of the jet stream, which a few days ago appeared as if it would have a negligible impact on the weather through at least New Years. With each cycle of model data however, there is more and more evidence that a low center with Gulf of Mexico origins will indeed move up the Atlantic Coast and impact New England with its moisture.

We discussed the idea of the limited amount of available cold air this weekend over New England. The current air mass will modify and the bitterly cold air will advance to most of the east coast a day after this system exits. Across coastal sections of New England, precipitation will fall as plain rain through much of Sunday. Moisture from the Gulf/Atlantic southern branch system pushes into Vermont just as energy from the clipper system begins arriving from the west. If the two storms were to phase, a bit earlier it would open the door for some incredible upside. Models right now are indicating that this won't quite happen, but we do have barely enough cold to support some snow late Sunday into Sunday night. Remnants of the clipper system and some lingering instability will help support some additional terrain induced or Champlain induced snow showers Monday. I think there will be some better clarity on accumulation totals in the coming days but snow Sunday afternoon, Sunday night and snow showers Monday should total at least 4 inches over that 24 hour period and perhaps upwards of a foot. Because this situation has evolved so much in just 48 hours, we have to leave some room in the forecast for some additional changes so I would expect some modifications in the coming days or so.

Bitterly cold temperatures will make a grand entrance Monday with the aforementioned snow showers. The region, as mentioned in previous updates, will be in the firm grip of arctic air through much of the New Years week thanks to the emerging western North American upper ridge and the negative Arctic Oscillation (AO). Snow could fall from a weak clipper system around the time of January 2nd. By the first weekend of 2014 there have been hints of some southern branch activity combining with the Polar Jet to produce a storm of significance but those hints were mainly yesterday. Today's models/ensembles suggested some additional snows from a clipper along with what should be the continuation of very cold weather. There are also indications that the position of the western North American ridge will retrograde toward Alaska allowing arctic air to loosen its grip on the region around the 7th or 8th of the month. This would go against my idea of the cold weather persisting through January 10th. The AO though is expected to remain negative throughout much of the first half of January, an important ally to have in the prevention of any damaging thaws.

Arctic chill looking for a long tenure at the throne

We took a few good upper cuts from the recent thaw but we did make it through. Perhaps I should try anesthesia for the next thaw because mentally, its rather tough to watch good powder go to slush and then crust. The cold weather is back in a big way though as temperatures on the mountain will hover near 10 degrees during the afternoon of Christmas Eve and Christmas day and should fall below zero Christmas morning. Aside from some snow flurries, enough perhaps for a dusting, it should be a relatively dry two days on the mountain. The next chance for accumulating snow comes Thursday from this clipper we have been watching. We continue to hope that as this system swings through southern Canada, it can tap at least limited amounts of Atlantic moisture and deposit at least a few inches of snow on the mountain (because we need it). The European model continues to be the more vibrant solution regarding this storm and even this result would generally suggest less than a 1-4 inch event for the 26th into the 27th. The Canadian and American models show a meager dusting to an inch or two. 

The cold weather will remain in place for the first part of the weekend but temperatures could actually sneak above freezing Sunday given enough sunshine. After snow flurries and a few snow showers Friday, most of the weekend will be free of snow or any precipitation. The warm day Sunday will occur as the overall weather pattern re-aligns itself into one that will, for the first third of January produce a large amount of brutally cold arctic air into both the Great Lakes and New England. Given what we have seen from the intensity of these air masses so far this winter, it is a good bet that readings will nose dive into the -10 to -20 degree range on 3 or 4 of these first 10 days of January. The culprit is will be development of a weak to moderate positive-PNA pattern which will align itself with what we expect will be a weak to perhaps moderate negative AO. The PNA magnitude (although it isn't actually measured this way) can be loosely measured by the strength of the ridge in western North America. So far this winter, we have not seen much of a ridge in that part of the continent and Vermont has been cold in spite of it. By the new year, we are expecting a ridge to develop over British Columbia and this will focus much of the unmoderated arctic cold over Vermont and other nearby areas.

Of course, we need snow to go along with this cold. Another clipper system, which will arrive late Sunday into early Monday, will bring the next chance for snow to the mountain. This system marks the first big intrusion of cold in the newly aligned pattern. After that, much of the energy in the jet stream will shift south as will the storm track. If it doesn't shift too far south, it opens the door for future clipper systems to continuously deposit additional snow and one of those could evolve into a more significant  snow producer given some constructive interaction with the Atlantic Ocean.  To get a big monster storm, we need the flow to split underneath the positive PNA in the west. This would allow southern branch energy to undercut part of the pattern (without destroying it) and the result would be a steady stream of 1-2 footers like we saw in 1993-1994. No indication of that, at least as of yet but we do still have the door open for terrain induced and Champlain induced events that will also make a contribution during the early part of 2014. 

Ice and more yuck through Monday but sustained cold weather takes the wheel after that

The front is oscillating up and down through Vermont Saturday. Unfortunately, the warmth pushed just far enough, north and I mean just far enough north, to allow the warm inversion to mix down to the surface and push temperatures close to 50. This boundary between warm and cold was literally positioned across I89, extending west southwest across the southern Adirondacks. Burlington's temperatures remained in the high 20's Saturday and temperatures remain in the high teens near the Canadian border. Oh well, chalk that up to some first class misfortune.

As of late in the day Saturday, the colder air is making a push south behind the first wave of low pressure and ahead of the stronger storm advancing toward us from the Ohio Valley. Temperatures will again be near the freezing mark Sunday morning while rain or freezing rain is falling. Looking at the temperature cross-sections, it looks like some sections of the mountain might see significant icing while other areas might remain a touch above freezing, it is literally that close and temperatures will for much of the day be within a degree of the freezing mark on either side. Saturday's temps will be the warmest we will see in some time but we will see another period on Monday where temperatures hover around 40 for a time before falling back below freezing by the evening.

The mountain will be back in the firm grasp of arctic chill Tuesday morning with readings near 10 for much of the day. Without much in the way of new snow to speak of through Christmas day, it will leave things a bit crusty, a good time to test the sharpened edges on the groomers. We had talked about our next chance for snow coming the day after Christmas as temperatures moderate in advance our next reenforcing shot of cold. The European model continues to drive the snowiest train on this particular system since it allows a relatively strong clipper system to gather limited amounts of Atlantic even some Gulf moisture and deposit a much needed 4-8 inches of snow to the VT high country. The Canadian and American model packages seem less intent on doing much of anything with this clipper, and the result would be more along the lines of a dusting to 2 inches of snow.

It once again gets chilly late Thursday into Friday which sets the stage for a rinse and repeat situation with questions regarding another clipper and another reenforcing shot of cold around the time of the 29th. The Arctic Oscillation is going to take this critical turn toward negative country around the new year or just before it. Specific results are a bit hard to make sense of this early, but generally speaking, we should the polar jet overwhelm a good part of the United States and lots of very cold weather through the first 7-10 days of 2014. When the polar jet is too overwhelming, in can prevent organized storm systems from having a big influence on interior New England but at the same time, sustained cold can never hurt and clipper systems can gradually fluff the mountain back into shape.

A tough weekend lies ahead

Lots of stuff to sort out as we head toward the Christmas holiday and as of early Thursday morning, we are beginning to get some better clarity on the coming weekend. There is a lot to cover and could make the update seem a bit long-winded but bear with me. Unfortunately, the mountain will have to play some defense against a weather pattern that wants to push very mild temperatures into New England. Barring a late inning change, we  have have to endure some less than ideal stuff (Perhaps we should call in the 2013 vaunted Red Sox bullpen or David Ortiz for some heroics) Arctic cold will put up a massive big fight on our behalf to maintain some control on our weather; in fact, by Sunday I can almost envision one of those epic battlefield scenes in a movie as the appropriate metaphor for the clashing of these air masses. The big consequence of all this is of course, a lot of weather. 

 

A decaying wave of low pressure will provide the region with the initial taste of precipitation Friday. The boundary responsilbe for the upcoming warm push will reach central and northern Vermont but will stall during the day and precipitation is likely going to be a wintry mix, starting as snow and going to a sleet/freezing rain mixture. At some point we could get a period of plain rain also but at least on Friday, this problem will be minimal. Mountains such as Jay Peak and points north will be positioned north of this aforementioned boundary and are likely to get mostly snow and minimal sleet/freezing rain from Friday's more benign system.

 

I expect some occasional light freezing rain/drizzle or some light rain or drizzle but much of the day Saturday will just feature clouds and some areas of fog.  As this is happening our bigger storm will move out over the southern plains, gather moisture from the Gulf and begin to head northeast toward the eastern Great Lakes. Since the last update, models have suggested that this storm will deepen (strengthen) quicker and track farther north right into the heart of the St Lawrence Valley. This will put the onus on a potent artic high pressure center in northern Quebec to dam  whatever is left of the cold air across interior New England, a challenging task considering the track of this storm.  There is time for some late inning changes, and even a slight shift south in the trajectory of this strorm could have a serious impact impact on the results. As it stands now however, a major of intrusion mild air between 5,000 and 10,000 feet in the atmosphere takes out the possibility of snow. The inversion is so strong in fact, that it could create a situation where many of the summits on the Green Mountain chain are noticeably warmer than valley locations. It could, during a significant part of the precipitation event, be the difference between ice or plain rain.

 

Precipitaiton over the mountain becomes more intense Saturday night and there is a threat for some serious icing if temperatures are at or below the freezing mark. It is very close call but since we are anticipating 1-2" of liquid precipitation, the icing situation could rival anything we have seen in the last decade or so if temperatures stay below freezing. If the storm would track over Vermont, it would open the door for more sleet with is a much more ideal early season scenario since it would provide a big anchor to our early season base. Although this is still a remote possibility, I think the more likely scenario is freezing rain or rain. Even this less than ideal situation should not become a complete debauchery, temperatures across most of the mountain should stay in the 30's, mostly in the low 30's so although there will be some melting, it will not be a total melting. The rain or ice should end during the afternoon Sunday and temperatures will gradually return to normal by Monday afternoon along with some some snow flurries.

 

The Christmas holiday week will feature a cold day Christmas Eve followed by moderating temperatures Christmas Day and the 26th. This could go one of two ways  at this point. Around the time of the 26th, we could see a weaker storm system, maybe even a clipper, spread some light snow into the region ahead of what should be a reenforcing shot of cold weather very late next week or into the the last weekend of 2013. We could also see something more along the lines of what the recent European model indicated which was a more organized storm system another round of a wintry mixture of snow sleet or freezing rain. After a glance at the ensemble data, i didn't get the sense that the Euro solution was a true representation of the model conensus so I would expect that the 26th is our next chance for at least a light accumulation of plain snow followed by colder temperatures on the 27th.

 

There are signs around the new year that the Arctic Oscillation will finally turn negative but this will compete somewhat with the evil empire in the Pacific. We saw a lot of this in 2012-2013 and the results are all over the place. For the time being though, the upcoming weekend represents the only major elongated threat of above freezing temperatures and in the end, temperatures may not get above freezing by too much.