Sunday, November 17, 2013

Priming Tonight's Late Night Squall

Tonight's squall line is a ways off from hitting us as of 5 PM -- the line has produced lots of tornado warnings and a squall of straight line winds. The latter of these twin threats is pushing towards us for late tonight, with the potential for winds above 50 miles per hour as the front approaches and moves through late tonight.

As we stated this morning, the threat is generally timed for 3-5 AM locally. The radar shot below is from 3 AM, showing the line moving in on Pottstown and West Chester to our west. This line will not be as potent as it presently is in the Midwest but will still pop some bite as it marches east.

The reason for that is the robust low level jet -- winds at 5000' in the atmosphere continue to be modeled at 60-75 miles per hour on the NAM, GFS, and other higher resolution modeling out there. The bulk of this wind threat is generally confined to city and points north if you look at the GFS and high res modeling. Winds could gust to over 50 mph, especially north of the city.

The result is potential for some power outages, downed tree limbs and branches, and blown over trash cans and other assorted outdoor stuff that easily blows over.

The line is fast-moving, heading east at over 50 miles per hour. It will not mosey through the region overnight -- it will probably clear the coast by sunrise and the result is a drying, but breezy, Monday in the region.

More: Current Weather Page