The arctic front has moved through the area and very cold air will filter in for the weekend and much of next week.

Saturday will be sunny but will also  have some instability cloudiness, especially during the late morning and mid day hours.  It will be windy and cold.  High temperatures near 31.

Sunday will be similar to Saturday with windy conditions and some periods of instability stratocumulus, especially mid-day. High temperatures near 35.

Following a cold weekend, attention will be turning to a strong coastal low pressure system that is expected to develop late Monday night from an upper air disturbance dropping down from the northwest and interacting with an inverted coastal front off the southeastern coastline.   This potential system was remarkably predicted by the GFS model as much as two weeks ago.

If things continue to play out, this system will be the most intense to affect our area this entire winter.   The current question is how close to the coast will it develop; too close and we will have mostly a mix of snow and  heavy rain, with high winds.   Slightly off-shore and we might have a major snowstorm.  The latest GFS model favors a large snowstorm, with up to 15 inches of snow around PHL.

That said, the devil is in the details and the long range experts at the NWS feel this one is going to be tough one to predict accurately, even in the short range.

This storm will differ from today’s snow maker.   The ground temperatures will be cold and the QPF values will be much higher.  The March sun angle is an issue, but a large portion of the snow may occur before daybreak on Tuesday.     Stay tuned.