Thursday Afternoon Technical Discussion

Synopsis:  After an unexpected 4 inches of snow yesterday across the commonwealth, temperatures have sprung back into the upper 30's as a low pressure system over the Great Lakes brought in warm air from the south.  A large meridional trough will dig far south for the eastern CONUS that may induce unsettled weather for the eastern portions of Pennsylvania beginning Friday night into Saturday morning. The 18z NAM shows very unorganized development of precipitation for extreme southern portions of the state overnight on Friday.  This solution cannot be ruled out as the 12Z GFS and EURO model agree on a more organized scenario.  The main focus will be the southeastern portions of the Commonwealth within this system, but expect scattered rain and snow showers for now.  Skies will then clear out with strengthening winds on Sunday with below normal temperatures barely making it above the mid-20's. Next week seems unsettled with a  storm potential Tuesday with a threat for rain and or snow.  The long range continues to look unsettled with many threats for rain and snow.  

Short Term:  Tonight's low temperatures are forecasted to be slightly above normal, but with overcast skies and snow cover, these temperatures may drop into the mid-20's .  The storm system that will approach the region on Friday night into Saturday morning appears to be just rain and snow showers as depicted on the 12ZGFS/EURO.  If the 18Z NAM follows through, expect mostly cloudy skies with the possibility of some scattered snow and rain showers.

Long Term:  As the Arctic cold front passes the region Saturday night, low temperatures will drop into the upper-teens, especially in the western portions of the Commonwealth .  Winds will pick up on Sunday causing breezy conditions as high temperatures are expected to sit in the 20's.  The long range 12Z  GFS and EURO have storm systems crossing through the region every few days with a threat for rain and/or snow.  A couple models are showing a possible very strong storm system towards the end of next week.

Michael DiDomizio
The Pennsylvania State University | Class of 2013
B.S. Meteorology | Forecasting and Communications Option
Minor | Climatology