Friday, January 20, 2012

Dry Friday

Flurries and light snow fell last night -- in the atmosphere locally and in the Poconos in reality.  Dry air at the surface and in the lower atmosphere pretty much zapped the flizzard and clipper of any ability to bring snow to the surface outside of the highest of elevations.  Last night's clipper is exiting stage right, bringing in dry air in the wake on northwest breezes for the day.   Temperatures will be pretty similar to yesterday across the region -- mid 30's northwest, upper 30's city and southeast, with a 40-42 type reading possible along the coast for good measure.

Skies today will feature a mix of sun and clouds -- the most sun regionwide will be later on this morning through mid afternoon before clouds increase from the west with the storm system.   Precipitation should start up after Midnight (generally in the 1-4 AM timeframe from west to east) so travel in the evening hours should be fine.

 Tonight's event is still on track with no real significant changes -- this is a snow to slop event for the city and the immediate suburbs.  The only nudge if you will is that modeling from last night has nudged this event into more of a "front end thump" of snow that ends as a period of drizzle/sleet/freezing drizzle for the outer Pennsylvania suburbs (Quakertown, Pottstown, Upper Chester County) and the Lehigh Valley.  A changeover to rain remains an issue for New Jersey (at least an issue for the snow starved), with perhaps some freezing rain in the transition out of snow on the front end of the event.   Our forecast numbers from last night look realistic -- if anything, we might nudge an extra inch of accumulation across the northern burbs and across the Lehigh Valley corridor, but the city is still on track for a general 1-3" event.   Because of the myriad of precipitation types, the NWS has a Winter Weather Advisory for the immediate Philly metro, Southeast PA, and Berks County.  Winter Storm Watches were nudged into the Lehigh Valley.

This isn't an epic storm by any stretch but it's our second legitimate winter event -- and first since October.