Technical Discussion 1-31-11

Synopsis:

 

A potent winter storm will begin to take shape over the next couple days that will impact just about everyone across the state. A mixture of wintry precipitation is possible for many across the state as the storm moves through tuesday and wednesday. Cold air will again infiltrate following the storm for thursday and friday.

 

Short Term (Mon. - Wed.):

 

Partly cloudy skies will remain for much of the state today, but clouds will build after nightfall with snow showers developing for the western and central parts of the state. This first wave of precipitation will move eastward bringing snow to the northern half of the state and a mix of precipitation to the southern half during the day on tuesday. The models are showing a general uniform total of up to a half inch of liquid water equivalent of precipitation with this first wave, which could be 3-5 inches of snow for the northern half of the state with smaller amounts in the south where sleet and freezing rain may mix in. The precip. will die off for a short time tuesday evening and overnight before the next slug of moisture moves in with the main center of low pressure overnight and into wednesday morning. The models are showing the critical 540 line moving up into southern New York state tuesday night and wednesday morning, which means much of central and northern PA will see freezing rain and sleet with areas to the south getting plain rain during the day on wednesday. The 09Z SREF shows this as well. A major threat for significant icing is possible with this second wave of moisture, so be prepared for some hazardous conditions. The storm will move out of PA overnight on wednesday ending with some snow showers for the western mountains as cold arctic air works its way in.

 

Long Term (Thurs. - Fri.)

 

The skies should clear for the end of the week, but cold arctic air will infiltrate much of the state as high pressure moves in for thursday and friday. Single digit low temperatures for thursday night are possible for much of the state with temperatures in the teens and 20's for the daily high on thursday and friday.

 

Josh Aikins