Monday, November 21, 2011

Updating The Tuesday Night/Wednesday Storm

We're still on track for a decent rain event on Tuesday afternoon through early Wednesday, with a stalled front to our south energizing with moisture and the influence of a storm system organizing in the Plains, lifting north as a warm front with a band of rain on Tuesday afternoon and evening before the main cold front crosses the region on Wednesday morning.   The potential for an inch of rain still exists as most computer modeling hints at an average rainfall of around an inch from this upcoming storm.

The first slug of rain on Tuesday afternoon and evening will move north, providing a break later in the evening.  Warm air will march up the coast, with temperatures probably rising Tuesday night ahead of the cold front.  We could see 60's across much of the region in the overnight hours Tuesday night, with low 60's ahead of the frontal passage on Wednesday morning.  There's still some uncertainty on timing the frontal passage, with the Euro and NAM still lagging behind the GFS in terms of timing the frontal boundary passage.  The timing of the frontal passage will probably be during the Wednesday morning rush hour (closer to alignment with the GFS' thinking), accompanied by a band of gusty showers and perhaps a rumble of thunder as it moves through.

Highs for Wednesday (60's) will probably occur with the frontal boundary passage during the morning hours, with a slow decline in temperature expected through the rest of Wednesday.   A brief cool shot ensues for Thanksgiving as temperatures will get into the lower 50's with mostly sunny skies.   With a lack of cold available in Canada to be tapped into, temperatures will generally remain mild through the duration of the week.  A colder shot of air lurks for next week but the pattern does not support a "locked" run of cold air for a while yet.