Friday, December 28, 2012

Saturday's Snowfall

Winter Weather Advisories are out for much of the region for Saturday as a weak storm system scoots by, spreading snowfall over the region starting tomorrow morning before it tapers off into the afternoon.  It's not a big deal system by any stretch but it will be the first accumulating snowfall for the city this winter after a plethora of trace events so far.  The advisory stretches up into the Poconos, down into the suburban South Jersey counties, and west into Central Pennsylvania.

The good news is that for most locations this event is a pretty cut and dry forecast.  If you're above I-295 or the New Jersey Turnpike, you should be all snow and shouldn't have any problems with mixing with rain.  Those of you below that boundary won't be as lucky but should be able to coax at least something out of this system.

Snowfall starts up during the morning hours from southwest to northeast -- we may have radar indications of precipitation as early as 3 or 4 AM but snow probably doesn't get going in south and west sections until 7 AM, in the city until between 8 and 10 AM, and northeast between 9 and 11 AM.   This  system is a relatively fast mover and it looks like whatever snow that falls should do so over a six hour timeframe, which means this should wrap up during the early to mid afternoon locally and points southwest, and mid to late afternoon northeast of the city.

Modeling has trending towards a wetter system in general -- not substantially more moisture, but enough to continue to justify a general swath of 2-4" in the city and northwest.  However, not only will it be a wetter system but it will likely be a slightly stronger system as it moves through.  This likely draws some warmer air northward along the coastal plain.  I feel pretty confident that everyone above the New Jersey Turnpike in South Jersey (up to I-195) should stay snowy.  If you're between there and about 20 miles inland, mixing *may* be an issue.  You're very much borderline and could waffle back and forth between snow and rain...with areas closer to the NJ Turnpike snow, farther south and east getting rain.

We're generally painting a two to four inch swath of snow across the city, north/west, and northern half of New Castle County, plus the immediate South Jersey burbs.  That in between zone could see an inch of slush...if it's more snow than rain, totals will be higher but one inch zone is the "high bust" zone.  The best chance of four inches, I think, is generally along and just above Blue Mountain across Central into Northeast Pennsylvania.  At minimum, you'll get two inches but it does look like the lower Poconos are the jackpot zone in this system.  Allentown, Reading, Quakertown could also get in the higher end of the two to four inch range.

Snowfall Prediction For Saturday

Coastal sections may see some snow at the tail end and generally should be mostly rain below Long Beach Island.