Sunday, March 28, 2010

Another east coast storm brings all rain to VT followed a season ending thaw

In the end, the storm early this week will be a microcosm of the season. The cold air which returned in time for the recent weekend has become stale and will receive little re-enforcing help. As a result the storm which will refuel along the North Carolina coast will have little cold air to work with and will spread rain into Vermont Monday and lots of it. There is in fact legitimate concern about flooding when you combine the nearly 2 inches of rain that is expected to fall Monday and Tuesday with the snow that will melt across the high country. The periods of rain should persist through Tuesday with temperatures generally in the low 40's. On Tuesday, the summits could see some limited snow before precipitation moves east and out of the region Wednesday.

Once the sunshine returns the weather will turn spectacular as promised late last week. It is a mammoth upper ridge which is expected to build across the eastern third of the country and this will allow for weather more typical of early June in Vermont as opposed to early April. The only competing force will be some marine air which could back in to interior New England sporadically; otherwise, temperatures will surge into the 70's on at least 2 and probably 3 days in the period between Friday of this week and Tuesday of next week. The warm air will be accompanied by some great visibility and plenty of sunshine. So long as the snow survives, the skiing will be great but the warmth is strong enough to put a mortal dent into the snow cover and will likely render parts of MRG unskiable by April 5th or 6th. With all that in mind the SCWB will probably get one more update before we call it a season.

Thursday, March 25, 2010

Winter makes a brief return but will fade quickly by late next week

Cold air has made its southward push in time for the weekend and a brief period of snow will whiten the mountain by Friday first tracks. The weekend however will be a dry one and will be preceded by a rare day of below freezing temperatures (Friday) and single digit temperatures in the morning Saturday. Light winds and full sunshine during the day Saturday should allow for a rapid recovery and slightly above freezing temperatures by Saturday afternoon. Sunday morning will be considerably warmer and the day should feature more clouds but relatively light winds and temperatures slightly above freezing during the afternoon hours.

As one of the warmer and snowless March's I can remember moves forward, the SCWB updates have gotten more sporadic but we continue (consistent with the last update) to watch a weather system on Monday. It is a potent southern branch piece of jet energy which will exit the central Rockies Sunday and make its way to the east coast by Monday. Its track is favorable for some MRG powder but the amount of cold air remains a question. The European model indicates a rather stale supply of cold air and thus limits the accumulating snow to the high elevations of the Green Mountains and the snow itself would be of the wetter variety. The American GFS model indicates that a fresher surge of cold air will become entrained in this system and we would thus look forward to several inches of powder across the entire span of the mountain Monday. The differences between the two models might seem small but have huge consequences. It involves a small piece of energy in the polar jet, a branch of the jet which has largely been confined to Canada this month. The GFS model however allows some arctic air from this branch of the jet to get involved in Monday's system while the European simply confines all the polar jet energy to the north. We can settle for a compromise for it too would yield snow on Monday.

If Monday's system fails to materialize it will be lights on the the winter. Not to say we can't get more snow in Vermont come later in April but the thaw that is to come by late next week will be massive. It will result from ridging in the Central Pacific and unsettled weather across the west. This will allow a Bermuda high to form and the warm air to surge northward. And when I say warm I mean "warm" not "mild". Temperatures in the valley locations will surge to 70 degrees and beyond across the low lying areas by late next week and into the weekend. It will make for incredible spring skiing so long as the snow survives but those temperatures will obliterate the base and likely put an end to the MRG season in short order. I would take advantage of the warm temps early while the snow lasts. It will also be a terrific time to head up to Tuckermans Ravine as there should be several days of fantastic visibility and tolerable winds to accompany the soft snow.

Sunday, March 21, 2010

Storm system to bring lots of moisture to Vermont but cold air is lacking

The cold air has been lacking for much of the month and the first 21 days has averaged an astounding 10 degrees above normal. The warmth has certainly corned up the snow quite nicely and the sun and relative lack of wind has made it pristine for outdoor activities. The snow, however is melting fast and a storm is very much needed in order to extend the winter season.

A storm is on the way and one which could have very much extended the season with the support of any cold air. Unfortunately, the cold more or less spent itself into bankruptcy across the western U.S. and will do little more than return temperatures to within the ballpark of normal. Meanwhile we have a storm system in the southern half of the U.S. which is spinning eastward and bringing rain to the 2010 snowbelt (Washington D.C.). This storm will grab Atlantic moisture as it moves northeast and spill it on much of Vermont and interior New England. Temperature profiles reveal a relatively warm lower 6000 feet of the troposphere and I would expect nothing more than rain below 2,500 feet. The rain will begin rather lightly on Monday but gain intensity by early Tuesday and should fall moderately and occasionally heavy through much of the morning. Above 2,500 feet we could see some snow mix in but temperatures should remain slightly above freezing so it will be a wet day for sure. As the storm continues to gain intensity and pull away to the northeast, colder weather will allow for more snow at the summits and for rain to change to snow at the base. This could lead to a few inches by Wednesday but the accumulations will be very wet at the base with only the summits having any chance for real powder. This is another storm which could have been a real winner for MRG but this winter has produced a litany of events where at least one puzzle piece always goes missing. In this case we have the moisture and we have a relatively favorable track but have little cold air. The event could bring 1-2 inches of rain to much of the Green Mountain spine which will damage the remaining bases to a degree but should not eliminate them entirely, particularly across the summits.

Snow showers and flurries will continue most of Wednesday and into Thursday although temperatures at the base should remain above freezing for the most part and any precipitation could be rain in the valleys. Late on Thursday, we should see a fairly good "punch" of cold air make a push into New England. This could bring a burst of snow to the mountain and finally bring temperatures universally below freezing on Friday. We will be watching a more organized storm system by the weekend but I don't think its impacts (rain or snow) will be felt until later on Sunday leaving the weekend free of any big precipitation. Temperatures will rebound to above freezing levels during the day and 20 degree readings at night.

The storm mentioned above does have some cold air as an ally but it track is a question mark and thus so is the precipitation type. At the very least we should see some terrain induced powder in the wake of whatever does evolve. It will mark a 3-4 day stretch of relative cold but it won't last as ridging in the central Pacific will again shift the storminess into the Western United States. It will thus likely be a rather mild end of March and early April and should set the region up for more spring conditions on whatever snow remains.

Sunday, March 14, 2010

Quiet weather to encompass region in the wake of the departing storm

Consistent with March traditions the weather has gone from very quiet to very stormy and will again go back to quiet. It has been a weekend of wind swept gails which have not only impacted many east coast locations but also the beloved single chair at MRG which is ashame but it yet again proves nothing is as effective at closing the single as the wicked east wind.

The duration of this storm will feature snow at high elevations and rain in valley locations. With little available cold air this is a system that is ever so sensitive to elevation and the threshold elevation for snow as opposed to rain will lower late Sunday into early Monday. This will allow the mountain to pick up a few inches of snow although the "powdery" stuff will be confined to the upper half of the mountain. All precipitation will be over with by the middle of the morning Monday and clouds may give way to a bit of sun. Monday should be the only real blustery day but temperatures should still creep above the freezing mark across most of the mountain.

The only disturbance of note for the upcoming week will pass well to our south west and this will set the state for a dry and "quiet" week as I mentioned above. Temperatures will climb to above freezing levels every day of the week and in most cases get well into the 40's. We should see an additional surge in temperatures Friday afternoon setting the stage for a very mild and spring-like weekend on the 20the and 21st of March. The push of warmth is a direct result of surge of upper level energy which will dive into the eastern Rockies late in the week. A weather producing system will develop as a result of all this along with an accopanying push of colder weather. Until this system reaches MRG, it will remain mild and the storm is not expected to impact Vermont until early in the week of March 22nd.

The NAO will remain negative but the effect of this teleconnection will be mitigated by blocing across western Alaska. This will allow cold and unsettled weather to focus itself in the Rockies while cold an unsettled weather although not totally absent from Vermont will transition through the region only to give way to milder temperatures. This is more or less what I expect March 22nd and beyond. Rain followed by some colder weather and perhaps a bit of snow followed again by a quick return to milder weather. I don't think unsettled weather of any sort will "persist" across the region until very late in the month or in April.

Thursday, March 11, 2010

Most of the rain stays south of MRG this weekend...

and this news would be the best we have received this week. In the end the middle of March will be very much on the tranquil side much like the European Ensemble predicted it would more than a week ago. After a calm Friday with clouds and some sunshine, temperatures will graze the freezing mark Friday night but should quickly rise into the 40's Saturday as easterly winds usher in milder temperatures. Clouds should thicken Saturday but the rain should hold off and remain well to our south. The rain and wind will in fact be quite a problem further south as low pressure along the eastern seaboard intensifies but the weather at MRG will be on the quieter side and the snow should remain soft thanks to a solid day of above freezing temperatures.

Sunday could turn out very similar to Saturday but models continue to show moisture gradually encompassing more of interior New England and ultimately bring a brief period of rain to the mountain during the day Sunday. Sunday will turn out to be the cloudier day and a solid night of above freezing temperatures should precede the ski day so the snow should remain soft. Temperatures should remain rather steady during the day Sunday either in the high 30's or low 40's depending on elevation. Overall rainfall amounts now appear to be in between a quarter and a half an inch. This is far less than I would have expected a few days ago and represents the key change in the weekend forecast and a good one as far as the telefest weekend activities are concerned. Rain should also be a middle to late day phenomenon and persist into at least part of Sunday night.

The other change of not involves much of next week. The forecast has warmed significantly in this time frame and the forecast of a "below normal temperature bias" appears to be not a good one. It should nonetheless remain dry however and this will allow temperatures to fall back to below freezing levels Monday night following some rain early in the day. Day time temperatures between Tuesday and Friday should have little trouble eclipsing the freezing mark. The week will start out on the blustery side thanks to the intense east coast storm but gradually winds should subside and the afternoons will be very comfortable for all outdoor activities. The shift in expectations was a fairly large one fundamentally. Although some evidence exists of blocking at some key high latitude locations, the focus of unsettled weather will shift into the west by late next week and this will allow temperatures to remain on the mild side through the weekend of the March 21st. We should see some cold weather return thereafter but by that point much of the support from our teleconnection indices will be lost and I am skeptical weather we can produce a weather pattern capable of delivering even a week of winter weather late in March. It perhaps may wait until April.

Monday, March 8, 2010

Late week storm shifts north but so does the cold air

With that news, I can't help but to resign myself to the thinking that Vermont has simply failed to own the 2009-2010 winter. As of Monday March 8th, our limited amount of winter cold was expected to receive some reinforcements. To a degree, this will happen but not on a noticeable scale and the cold weather this week does not appear strong enough to withstand a surge of warmth that will accompany the moisture from the next storm.

The weather system in question is a southern branch piece of jet energy with plenty of moisture. As Vermont continues to see dry and seasonable temperatures in the Tuesday to Thursday time frame, this storm will track out of the Rockies and into the central plains. From here, the storm will dance and spin its way toward the Atlantic Coast and position itself near the New Jersey coast by Saturday. This would seem to be a very favorable path but the storm will mature very quickly in the plains and ultimately occlude before reaching the eastern seaboard. The occlusion process, much like the powerful storm two weeks ago, has the impact of allowing warmth to wrap from the eastern flank of the low pressure center to the northern flank. The moisture which is likely to make its delayed arrival in north-central Vermont sometime on Friday, will arrive after much of the limited amount of cold weather is scoured out. At the very least I was hoping the high elevations could salvage something out of this event but preliminary temperature profiles across the region during this time frame suggest even this may be a stretch. In summary, unless we get a big fundamental shift in the way this storm evolves late this week, it will be rain for Friday, Saturday and rain and snow showers for Sunday and Monday. I know this is disheartening news given that the big telefest weekend is upon us and adds to the frustrations that seem to be way too common this winter in our parts.

The general period between March 14th and March 21 still appears favorable as far as winter weather is concerned. I expect temperatures to be biased to the cold side as a consequence of a positive surge in the PNA index. The departure of the storm this weekend may allow snow showers early next week and we will then hope the storm track remains far enough to the north to get in on the next weather system which will probably be around the time frame of March 20th and 21st.

Friday, March 5, 2010

Winter loosens its grip a little but not entirely

Temperatures, with the help of lots of sunshine, have been allowed to warm above the freezing mark during the day time hours but fall well below that at night. I am told that is excellent for the maple syrup folks although I am hardly the expert. This general trend will continue for the next several days and temperatures will be allowed to reach the 40 degree mark across the low lying areas Saturday with the help of more sunshine. A few clouds and perhaps a few snow showers may mitigate the temperature rise Sunday and Monday but it will for the most part stay dry and we should see some sunshine Monday and more on Tuesday

One of our readers, "Cowbells" pointed out a few days ago that the middle of the month might not be the sea of tranquility I had indicated in the last post. It was the American GFS model then and continues to be the American GFS model now which indicates a rather interesting finish to next week including snow from a juicy looking storm system followed by terrain induced for the weekend. The European model is showing much of what its ensemble members showed a few days ago. More storminess to our south and dry weather across the Adirondacks and interior New England. The differences are derived from the handling of the jet stream blocking across Canada. The GFS and its ensembles allows the blocking to shift to the west, opening the door for storm systems to move up the Atlantic Coast as opposed to out to sea. The European maintains that much of this blocking remains across the central part of Canada and this forces much of the available jet energy to remain well to our south much like it has for much of the winter. This one is a very close call however and although the weather could turn out just as benign as I would have indicated in the last post, it was right of Cowbells to widen the possibility spectrum a bit. At this point we certainly have at least a chance at getting in on the action late next week and into the weekend and it will be worth watching over the weekend since I know telefest is St Patty's day weekend and plenty will be keeping an eye on the weather.

Moving beyond the weekend, no spring thaws are evident although the major ensembles are arguing about the extent to the wintry weather. The GFS ensembles produce a rather cold week in the wake of telefest that would certainly include a few powder days. The European would indicate that temperatures are on the below side of normal but with a more stable pattern. With the 50-60 inches of snow over the past 10 days, the weather should allow for the MRG season to continue strong through the official start of Spring and beyond.

Tuesday, March 2, 2010

More juice in the south

As flurries continue across the high country of Vermont another in a long list of southern branch storms is poised to make a run up the Atlantic Coast. The storm will be embraced by the expansive east coast trough currently in place and will move from the panhandle of Florida Tuesday to somewhere east of Cape Hatteras by Wednesday. From there its track is expected to continue in an east of north trajectory and this will make it difficult for its moisture to reach much of interior New England. Areas that will see snow from this will be areas that have already seen record snow during the winter season. The track of the storm will be a bit too far east and thus snowfall across the bigger cities may avoid the record books but it will be nonetheless snow that MRG will mostly avoid. Both Wednesday and Thursday will feature temperatures in the 20's and snow flurries but nothing of real merit aside from a flurry inch or two.

Thereafter, a more tranquil stretch of weather should settle into the region. Healthy amounts of sunshine and the high March sun angle will also allow temperatures to warm considerably and we may get a few days of spring conditions before the next shot of cold arrives sometime next week although there is still some disagreement about this. The warm up results from some structural changes in the ridging and blocking across Canada. The ridging had shifted back into western Canada and had thus allowed the PNA to turn positive but over the next 5 days, the blocking will shift into eastern Canada and will extend south into New England. A real spring thaw consisting of 50-degree temperatures is possible but the warmer of possible scenarios. The European has suggested 1 or 2 days of garden variety warmth followed by a turn to colder weather during the middle of the week. This return to colder weather would mark our next chance for snow but this will have to be clarified in a later update since it is a bit early for details.

The middle of March weather pattern appears somewhat familiar. A ridge or a block across central Canada will likely keep arctic air from spilling into the U.S. in large quantities and will also suppress the southern branch energy which has already been suppressed for much of the year. This set-up thus threatens to allow for a relatively dry middle of March but we will continue to keep an eye on it.

And lastly, a congratulations need to go out to the Canadians and the hockey team that represents them. In one of the most thrilling games I have ever watched, Canada prevailed in a extra period and won the gold medal in spite of a very gritty effort from the United States. It was a great moment for the great sport of hockey and it might be wise to remind the less than stellar NHL commissioner, Gary Bettman of this before the next round of Olympics when NHL players might again be playing in meaningless regular season hockey as opposed to representing their countries.