Friday, February 01, 2013

Clipper Mania

The combination of pretty insane snow ratios (perhaps up to 20 to 1 in parts of South Jersey) allowed for convective banding of snow to explode into a nice South Jersey snowstorm this morning.  Modeling indicated the potential of a couple to perhaps three inches in parts of Delaware and Cape May in New Jersey -- they got the placement right but underdid the intensity and the "fluff factor" which helped produce a rather robust snowfall across these areas.

The dynamics with this morning's clipper were pretty robust, especially with the intense banding setting across Central Delaware through Cape May County and providing for the robust snowfall seen this morning -- and a small mesoscale band of snow fired up across Reading and shoved quickly southeast between 8:30 and 10:30 AM, spreading a quick coating to half inch of snow across the 422 corridor and through the Main Line.  The quick hitting nature of this band of snow fed into making these areas a traffic "treat" across the western burbs for a time.

Snowfall rates across Cape May and Central Delaware averaged in the two to three inch per hour range over the 7 to 10 AM timeframe, resulting in a rather amazing little snowfall for these areas.  These little events -- mesoscale, small-banding snowfalls, have a tremendous ability to generate lots of snow in small geographic areas.  They are tougher to predict and in many cases are "nowcast" type events.

Onto the next event, which is tomorrow night into Sunday.  This storm will have a bit more moisture on a widespread basis over the region but should not have as intense as dynamics associated with it that this morning's snowfall had.  That said, modeling does indicate the potential for another small scale band of snow to fire up as the clipper intensifies once in the Atlantic.  The NAM from mid afternoon today shows the potential for some two plus inch amounts over Central and North Jersey's coastal sections, plus the Poconos, with one or two inches common elsewhere.  This is assuming ten to one ratios...if we get higher ratios on the order of 15:1 we could see some four or five inch snowfall totals across Ocean and Monmouth County if this particular run of the NAM is right.

Timing for this suggests a Saturday night into Sunday morning move through, although some snow showers and flurries are possible as late as mid afternoon tomorrow to the city's west and northwest.  The bulk, however, is geared for tomorrow night.

We'll provide another update tomorrow morning on this.