Thursday, November 17, 2005

Cool Regime In Place

After Wednesday's record highs and significant rainfall (over an inch of rain in the Western Suburbs), we are entering a period of cooler-than-normal weather. We are entering into a dip in the jet stream which has tappped into some pretty chilly air up over Canada.Temperatures yesterday afternoon just north of the Minnesota/Ontario border were in the single digits with teens common throughout a good portion of Minnesota.

For Thursday, expect temperatures in the mid 40's with upper 40's not out of the question in the city. Winds will gust to 25 mph earlier in the day but subside later in the afternoon.

Friday will likely be the coldest day of the forthcoming few as temperatures will struggle to break 45 in Center City and likely sneak past 41 or 42 in the burbs but not much more. We will start the day with temperatures in the low to mid 20's and the cold start will help keep us cold.

The weekend will be nice, sunny, and temperatures will be moderating towards 50 in Philadelphia. The trough will flatten some over the eastern US but we will still be seeing a flow that originates from Central Canada.
On the horizon, the GFS model is hinting at a coastal storm developing Monday night and into Tuesday. Something to keep an eye on and if anything does develop, snow is not out of the question for the higher elevations inland with a mix into the N/W burbs. This model has been trying to spit something out in the Tuesday time frame for a while so the concept of the storm or something impacting us and places NE of us such as New England should not be ignored or downplayed YET.The EURO has a system developing at 5 AND 6 days out off the coast. Seems a touch odd but I think the EURO may trend towards being on board as well for a precip event (see below for Tuesday night model projection).
The other thing to see is that this cold stretch looks to be much more persistent in nature. After our weekend modify to near 50, temperatures will drop back down with a reinforcing shot of cold coming in as both the EURO and GFS hint at a reinforcement near Thanksgiving. Long-term, some metorologists are looking at a similiar setup to December 1983 or 1989, both of which were tremendously cold Decembers for the Eastern seaboard of the US.