Thursday, March 17, 2011

Spring conditions have arrived but winter plans to fight back

Many areas in Vermont have seen a long awaited day of 50-degree temperatures. The warmth has corned up the snow and melted a large percentage of it in low lying areas. At high elevations however the snow depth remains healthy and well above average for this time of year and colder weather over the next week will ensure it remains that way. The question involves our chances for a late season snow.

As far as organized systems go, it's a mixed review. Cold weather will arrive in time for the weekend but the prevailing airmass is a dry one and the weekend will feature great visibility, a good amount sunshine and temperatures which dip into the teens during the early morning hours before rising close to or above 40 during the afternoon. By Monday another push of warmer temperatures will accompany the arrival of the next storm system. This low pressure center will travel up the St Lawrence Valley and will thus ensure that any snowfall is minimal at least initially. The moisture however will be moving quickly east and this could mean a period of freezing rain Monday. Colder weather will quickly become entrained in the storm as it moves east. This combined with some lingering instability could mean accumulating snow showers Tuesday as temperatures fall below the freezing mark.

Another system is likely to quickly cross the country during the middle of the week and it will be energized by a fairly violent clash in airmasses between the southward push of cold and the lingering warmth in the southern states. The moisture with this storm system is likely going to impact areas well to our south unfortunately. After a round of what we hope will be some accumulating snow showers Tuesday, dry weather will win the day for the later part of the week. It will however remain very cold with temperatures on the mountain remaining below freezing for an extended period of time. The cold weather will continue through next weekend which should provide the opportunity for another shot some new snow. Overall the teleconnection indices are very mixed. They are favorable at the moment but the NAO and AO will become conflicted within a week or so with the AO turning positive and the NAO remaining negative.

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