Pages

Wednesday, March 4, 2009

Spring-like temps for the next week to ten days but winter isn't done

And the most deceiving thing about March can be that initial blast of mild temperatures. They can arrive very abrubtly, can last a week and sometimes beyond, and seem to always give the inclination that winter has had its final encore. But rarely is the latter the case. Winter usually makes a comeback and indications are it will again.

The forecast warms
The forecast in the short term however has warmed quite considerably. The pattern appears more amplified than it did a few days ago and the cold and snow will be isolated to the western United States while a strong upper level ridge brings warmth to a huge part of eastern North America. Over the next week temperatures will reach the 70's across many of the same locations that just saw the biggest snowfall of the season Monday. Vermont is unlikely to see temperatures that warm, but high temperatures in the 50's should occur on multiple occasions through the end of next week and this means corned-up spring conditions even at the summits.

Some rain or ice late this weekend and perhaps more rain next week
As far as specifics go, we sould see the cold weather maintain its grip on the region through Thursday. At that time the warm front marking the swing toward the milder temperatures will help induce a period of snow, perhaps enough for a light accumulation. Whatever falls however will be forgotten by Friday as temperatures make a run at 50 with the help of some sunshine. Saturday's temps will start mild but clouds and the possibility of rain late in the day could dampen the spring fever. Saturday's late day rain marks the approach of what appears to be the most organized weather system of the upcoming 10-day period. It will track out of the southern Rockies and into the St Lawrence Valley of Quebec. This storm will be working with very little cold air and it may take more than a change in track to save us from a round of rain or freezing rain either Monday or Tuesday.

Winter makes a return around mid-month ??
Sunday's rain or ice event is likely not the last of the spring intrusion. More mild weather and more rain is likely at some point later in the week. Whatever days turn out to be rain-free and sunny will be the real winners. As the mild weather continues to prevail through next week the NAO index will drop and turn significantly negative. This should utimately lead to another twist in the pattern and a return to winter prior to the St Patty's day. Even the PNA, which will itself turn very negative over the next few days will eventually erode and may turn postive sometime around the middle of the month. History, as I mentioned in the first paragraph, would also suggest that mild periods in March rarely mark the end of winter's demise. My guess is that it returns in a big way for at least a week during the last half of March and yields a few powder days in the process.

2 comments: