6:20 AM

The low pressure system off the North Carolina coast is impressively deepening, and heading east-northeast this morning.  The man area of precipitation is already moving towards the Atlantic and well south of the forecast area.  However, with a stiff northeasterly fetch off the Atlantic, I still can’t rule out a few ocean effect snow showers over the New Jersey coast and Long Island.  I don’t expect anything significant, but I think those snow showers should be kept in mind for this evening.  Otherwise, a partly cloudy and breezy day can be expected with winds from the north and northeast around 10 to 20 mph.  Gusty conditions can be expected along the immediate coast and over the coastal waters as the low passes to the south.

The arctic air mass that has been in place, and that has supported several minor snow events for the forecast area, is on the way out starting tonight.  High pressure of Pacific/Polar origin will move into the forecast area tonight from the south.  The track of this high pressure system, though the Southeast, will support a southwesterly wind pattern from the surface to 850 MB.  However, the moderation of temperatures will only push temperatures back to near normal levels.  Otherwise, dry conditions can be expected through Thursday.

The pattern will be going into a brief state of reloading and relaxation for the last weekend of November, Thanksgiving weekend, and for the first five days of December.  As a result, the storm track I’m expecting will run from the Mississippi Valley to over the coastal plain and into interior New England.  In other words, the center of the cold air will move back towards the Plains, which places the boundary between the warm and cold air over the forecast area through this period, thus the storm track.  

The upper low will lift out of the forecast area on Thanksgiving Thursday with a few isolated snow showers followed by clearing skies.  Temperatures will remain in the near to slight below normal range with the maximum below normal of 4 degrees expected over isolated locations.  

Meanwhile, an area of low pressure will develop along an old cold front boundary over the Mississippi Valley.  I took a blend of the GFS, which is too far east, and the ECMWF which is slightly too far west in my opinion, for the forecast.  This will place the storm track right over the forecast area.  

With a lack of high pressure to the north, any type of cold air in place ahead of this low pressure system will exit the region.  I expect this low pressure system to produce rain for most locations with the possible except of the higher elevations of northeastern Pennsylvania and the Hudson Valley.  However, even in these locations I expect a mix of rain, sleet, and snow.  The accumulating snowfall can be expected over western New York and New England.  Why?  Look at the upper level pattern.  There is no hint (yet) of a negative NAO blocking pattern, which means cold air can not lock in.  

My gift to you for Thanksgiving is a word of advice.  Don’t bother looking at the medium range guidance for potential snow events until around December 4th-6th and beyond.  It is in that time period where I think we will see a negative NAO return as the pattern returns to a cold centered in the East and increased potential for Miller A and Miller B type storms for the rest of December.