Sunday, December 30, 2012

Cold But Generally Dry Week

In the wake of yesterday's storm and today's winds is a cold week ahead. This isn't an arctic or abnormally or historically cold stretch upcoming but it is a reminder that winter is here and that it occasionally does get cold around these parts. The coastal storm that's generating today's winds is going to get hung up along the east coast of Labrador in Canada, setting up a -NAO regime for the week and pushing a healthy dose of cold air into Quebec, Ontario, and New England.

We will get in on some of this cold but the core of cold will generally be to our north and northeast over the coming week.  Temperatures across New England could run eight to ten degrees below average through the coming week, with our region generally a few degrees below average on the whole.

Thanks to a fast moving jet across the country around the base of the cold trough, it looks like we're going to be generally dry this week as well.  A couple of storm systems will cross the country over the course of the week.  The first moves through Virginia and the Carolinas on New Years Day but as of now looks like it is probably more noted for spreading clouds over us than precipitation.  There could be a few flurries or sprinkles (along the coast for the latter) as the system nudges on by and drags a reinforcing shot of cold down from Canada.  However, because our airmass is dry to begin with and main storm system is farther south it could be tough to see much more than a few stray flakes around here.

The second storm system, for Friday, pushes through the Carolinas and Georgia.  Some older runs of the GFS tried to bring the northern edges of this storm up to Philadelphia before turning it out to sea but more recent guidance has nudged the storm farther out into the Atlantic as the core of cold over Southeast Canada and New England exerts a stronger lock on the pattern over us.

That means a cold, generally dry week around here, with the Thursday-Friday timeframe featuring highs in the lower half of the 30's in the city and probably not getting above freezing in a number of locations northwest of the city.  This pattern, like any pattern, will not last.  The core of cold will relax over the weekend and a milder regime may be in the offing for the early half of next week.  The warmth over Western Canada will dump southeast into the Plains and slowly ooze east as we work into the first full week of 2013, which means our cold week this week becomes a milder week next week.