Monday, December 12, 2011

Small Chance of Some Freezing Rain Wednesday Evening Up North

The next storm system will approach us in a couple of days and bring a chance of rain on Wednesday night to northern parts of the region, with showers for everyone on Thursday as it crosses the region.
Computer modeling from the NAM shows a shot of warm air advection showers (essentially warm air aloft working over a cooler, retreating airmass) moving across Northern and Western Pennsylvania on Wednesday evening.   Those showers should generally remain confined to areas north of I-78 or I-80 as they cross through as the airmass over our region as less favorable for precipitation.  Temperatures at the surface on Wednesday evening may be cool enough to support freezing rain or freezing drizzle as this area of precipitation moves through.   The air aloft will be mild enough to support rain but at the surface some lingering cold air in place (thanks to a weak cool front that crosses the region tomorrow) could help yield some freezing rain across the Poconos on Wednesday evening.   Even if temperatures do rise above freezing, travel for a time could be a bit slick.

None of that is really expected around here as most of the light precipitation should stay north of the city and temperatures will be a bit too mild (generally in the upper 30's or low 40's during the evening hours).   For those longing for winter, though, at least there is some "there" there on the map.  After this upcoming system moves through Thursday night, the next shot next week could bring more wintry fun a bit closer to home.  It's still several days away but modeling is hinting at some potential freezing or frozen precipitation a bit closer to the city (Lehigh Valley, Berks, perhaps the outer parts of Bucks, Montco, and Chesco) for a week from Tuesday or Wednesday.   Again, a way's off and a ton could change but it's better than tracking 70 and a flood if you're a fan of winter!