Category Archives: Philadelphia Weather Outlook

WEEKEND WEATHER OUTLOOK

The snow-free winter continues…

A cold front moves through on Thursday and cold high pressure moves over us for Friday and Saturday. The National Blend of Models (NBM) is showing highs of 33° for both Friday and Saturday although some statistical models (ensemble models) show highs to be a bit colder.  Skies will be sunny both Saturday and Sunday.

The pattern is fast moving and progressive; temperatures rebound into the mid 40s on Sunday as winds shift to southerly with the departure of the high.

The Extended Range GFS model attempts forecasts 384 hours (16 days) into the future. No potential snow storms are currently predicted, except a possibility the last day in February.  Don’t change your plans.

This winter has been characterized by a lack of large, dense, cold air masses sinking straight south in the middle of the country.  

There is a  common misunderstanding, perpetuated by TV weather entertainers, that the jet stream determines where the air masses go.  Actually, it’s really the other way around— the size, shape and temperature-density of the cold air masses in winter determine the position, shape and configuration of the jet stream. The ‘valley’ between the polar air mass and the tropical air mass is where the jet stream is positioned and where major low pressure systems develop and track.

The current pattern has been with us for almost three months. Like bull stock markets, weather patterns don’t last indefinitely. Weather patterns tend to change as the seasons change.

WEEKEND WEATHER OUTLOOK

Updated Thurs 11 PM —Tonight’s models are showing very high winds starting 9-10 AM Friday morning, especially from Philadelphia and east into NJ.


The fairly uneventful winter weather season continues here for the weekend.

Deep low pressure will be departing our area on Friday, and high pressure will build in for Saturday morning, giving us sunny skies but seasonably cold.  High 42.

Fast moving weather flow will be evident as clouds build in during Saturday afternoon ahead of a series of weak disturbances that will approach our area.

These weak disturbances have been handled differently by several models; the latest GFS suggests the chance of light snow flurries early Sunday morning as a result of one of these disturbances.  This feature has been inconsistent, with several models having shown this earlier in the week, then backing off.

Either way, Sunday’s morning clouds should break for sunshine by the afternoon.   High 46.

Another front approaches Monday with more clouds and showers.

WEEK WEATHER OUTLOOK

Saturday night’s model runs briefly showed the possibility of snow, however subsequent model runs have all moved to predicting mostly rain for our area Thursday into Friday.

A slow moving cold front in the Midwest will have waves of low pressure move up along the front, bringing rain, possibly heavy for Thursday into Friday. The precipitation starts late Wednesday evening or Thursday after midnight.  Some areas to the northwest of Philadelphia will have a period of freezing rain or sleet before daybreak, before changing to all rain.

NAM  forecast Simulated Radar for 1 AM Thursday morning – north and west of white line is below freezing at surface- possible freezing rain/sleet. The warm air advances northward by daybreak.

No snow seen in the current forecast.