Think Snow, Tweet Snow !!!

Wednesday, February 28, 2007

Lots of fresh powder for Friday morning then a little sleet

The Valentines Day Blizzard was the strongest winter storm to impact the region this season without question but the runner-up may be the upcoming March 2nd to 5th event. This is an entirely different beast but the news with this system is mostly positive since above all, its effects will be felt beginning Friday and persist into Monday or perhaps even Tuesday of next week. This is the second in a succession of huge winter storms for the Upper Midwest, an area which has been snow starved most of this decade. Usually, systems which strike the Midwest hard with snow bring a combination of snow and ice to Vermont and New Hampshire and the forecast challenge becomes predicting all of the precipitation types, amounts and the timing of all precipitation changes.

Storm details - 6-10 inches of powder for first tracks Friday
As the storm continues toward the eastern Great Lakes and brings a push of warmer temperatures with it, a second low pressure area will form near Long Island and re-concentrate the heaviest precipitation over Northern New England. More importantly, this second low will prevent some of the warmer temperatures from invading MRG and changing precipitation to freezing rain and rain. So here are the specifics as best as I can see. Snow will develop at MRG within a few hours of midnight Friday and quickly become moderate to heavy in the pre-dawn hours. Based on some of the latest higher resolution model data, a quick 6-10 inches of powder is likely by the time the single chair begins churning Friday morning at 9 am. This of course means some dynamite runs early in the day. Cross section profiles however show above freezing temperatures overspreading the region during the morning which would quickly change precipitation to sleet which is then indicated to continue through the duration of the ski day. Sleet although less than ideal is not terrible to ski in but can feel like needles driving in to your skin while skiing at higher speeds. Freezing rain may be less painful on your skin but I would hate to see a one inch glaze of ice atop the 3-6 feet of snow currently on the ground at MRG. This deplorable situation will be mostly avoided in northern Vermont since the above freezing layer is above 8,000 feet with well below freezing temperatures remaining in place below this layer. All in all, I think skiers will be happy with Friday's results. The heaviest precipitation is indicated to fall as snow and the icy precipitation is shown to fall as mostly sleet. Total accumulations snow/sleet by Friday evening will range between 8-14 inches. And by the way, precipitation goes back to snow Friday evening and may add a few additional inches to this total by Saturday morning.

Terrain induced snow for the weekend
What I am especially excited about is the set-up in the aftermath of Friday's precipitation. The upper low which is closely associated with the original Midwest winter storm will push slowly toward and through the region during the weekend and early next week. As a result, low level instability will increase and set the stage for a long duration terrain induced snow situation. Winds will be west-southwesterly and it will not be especially cold over the weekend. It may very well turn out to be one of those early spring situations where sunshine and near 35 degree daytime temperatures prevails in the valley locations while snow showers in the mountain locations are occasionally producing heavy snow. The highest snow totals strictly from the terrain induced snow are most likely to fall in the north but the additional snow between Saturday and Monday could very well exceed a foot at MRG and this would include significant amounts of fresh snow at first tracks time both Sunday and Monday.

Rest of next week/Telefest weekend
The terrain induced snow could very well persist through Monday Night into Tuesday since at this time a reinforcing shot of colder weather is expected to make a push into the northeast. Dry and cold weather will temporarily prevail for a time during the middle of the week before another system takes aim at the region, again threatening to bring a signficant push of warmer temperatures with it. We have stiffened our differences on two different occasions and will avoid rain in both instances but in this case (late next week) we are in hot water. The upper trough in the western provinces of Canada has been a persistent negative driver and with each passing system we are risking a bad outcome. The days leading up to telefest weekend are appear especially troublesome since both ensembles show a strong signature for zonal flow with the anomalous warmth centered over the northeast. Sorry to be the bearer of bad news but we may be forced hope to minimize the damage. Such a task is feasible if the warm weather is accompanied by sunshine and minimal rain and the jury on that is still out.

Is this it for winter ?
Actually, I think winter still has something left. I am still watching the Arctic Oscillation carefully and although it is forecast to go positive briefly it may not remain as such. For much of the country this may not mean much but I do think the weather remains interchangeable or more specifically, I don't think that any warm weather late next week or on Telefest weekend is permanent across the North Country. Unfortunately the pattern looks something short of sustained cold and snowy which simply means that after March 8th, we may have to look individually for the warm and sunny or occasionally snowy days. Remember the healthy MRG base when combined with the warm weather is a nice and welcomed combination late in the season.

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