Wednesday, April 10, 2013

April 11th, 2013 Forecast

Forecast trickiness tonight and tomorrow as a frontal boundary to our north begins to sag on south, tugged down from its perch to our north by a disturbance that is pushing east in the atmosphere.  Today's upper 80's will give way to much cooler weather during the day tomorrow as the front slides south of Philadelphia.  The questions are how quick does the front slide south and how quick do temperatures drop once it does.  As of now, we're thinking we can coax a few hours of decent weather in the morning before the trend south in temperatures takes hold, which means your drive home from work may be cooler than your drive to work.

Before that, thunderstorms are in the forecast for tonight, especially north of Philadelphia where two or three lines of thunderstorms are pushing east in association with the aforementioned disturbance.  Some thunderstorms will produce gusty winds, perhaps hail, but most of the thunder activity passes north of Philadelphia.  Lows by morning drop into the 50's north, 60's from the PA Turnpike (or thereabouts) on south.  The Shore will hang in the 50's overnight.

Thursday features the front sliding south and falling afternoon and evening temperatures.  Highs may not be much higher than morning lows in Allentown (and in fact, Midnight highs are possible north of the city), with temperatures topping out (hopefully) around 70 before the effect of mid 40's ocean-influenced air begins to air condition the city.   Clouds increase as the easterly flow pushes in low clouds off of the Atlantic...and clouds from the storm system over the Midwest approach.  By dinner, temperatures could be 10-20 degrees cooler than the midday highs in some spots along I-95.  The Shore won't budge much on temperatures, generally starting in the 50's and then sliding south after midday.

Since Thursday's forecast is tricky, we're going to provide a pretty decent update on it tomorrow morning with our daycast.