Sunday, February 26, 2012

More where that came from ?? Maybe a lot more

Sure !! sign me up. Its been a few days since the last update but not much has changed. Two systems will travel from the Rocky Mountains toward New England over the next 5 days or so. Both will be guided by a very typical La Nina upper level pattern. The first system, which should bring 1-2 inches to northern Vermont Monday, will not generate much excitement. This storm does not have significant amounts of moisture and its track up through the St Lawrence Valley is hardly ideal. It will however play an important role in the story and set the stage for a much more potent mid-week storm with lots of potential.

The Monday system, as it passes, will generate a critical confluence area in the jet stream over the Canadian Maritimes. A confluence area can be described as an area in the jet stream where wind speeds accelerate as one moves from west to east. Imagine traveling down a calm river in a kayak and suddenly encountering class 5 rapids. Its more or less like that. The mid-week system will move out of the Rocky Mountains Tuesday and threaten to follow the track of Monday's storm up the St Lawrence Valley. It being a stronger system, such a track would bring the threat of warmer temperatures and rain. The confluence zone will prevent such an occurrence and allow cold and dry Canadian air to establish itself over interior New England in advance of the clouds and the arrival of precipitation Wednesday. The result will thus be snow which should arrive Wednesday and persist through a good period of the day.

There are some questions regarding this storm even though I think the threat for rain and ice is greatly diminished as of Sunday morning. The various models show a varying degree of impact from this so called "right entrance" region of the jet stream. The European shows a profound impact and although it suggests a period of snow Wednesday, the snow is ultimately pushed south Thursday and total snowfalls would be in the lighter 2-5 inch territory. Other indications however show a much more significant period of snow and the possibility for a real "epic" style event. Snow would persist for a 24-hour plus period and could snowfall totals could approach 2-feet. It would be a heck of a way to start March.

Ironically, this is all happening as the teleconnection indices have all turned unfavorable. The pattern for much of the eastern seaboard south of New York city has been in fact very non winter-like. Washington D.C. is reaching 60 degrees it seems every day and parts of Virginia have seen readings approach 80. Much of this will continue through this week with a sharp divide between winter which will be confined to interior New England and spring which will continue to prevail in the Mid-Atlantic States. Looking out beyond the storm, this is shown to generally continue and there are continued threats for "thaws" and bouts of mild weather even across interior New England. So far this pattern has put us on the right side of the battle but we are living on the edge. If we strike gold with this storm Wednesday/Thursday take advantage of it because our good fortune might not hold up.

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