Daily Archives: Monday, March 23, 2026 8:37 am

Philadelphia Area Weather Forecasts

THIS WEEK’S WEATHER

#Philadelphia #weather #PAwx #PhillyWx

Update Thursday through Early Friday

Posted Thursday 03/26/26 @ 9:43 AM — A distubance along a cold front is poised to drop down into our area later this evening between 10 PM western sections and midnight east of Philadelphia.

Water Vapor image at 9 AM with superimposed RAP model MSL pressure (black contours), GFS/NAM potential vorticity contours (yellow & violet fine contours) with MRMS Radar and surface wind barbs, (Click on image for a larger view.)

Most of the instability and kinetics associated with this disturbance will be at their height long before the rain starts, so it appears that little in the way of severe weather is expected. One severe parameter suggests some strong thunderstorms possible about 2 AM, although the NBM is not on-board with this.

With the enhancing kinetics missing with the frontal passage, total rainfall is now expected to be in the 0.3″-0.5″ range instead of the 1″+ forecast by the HRRR yesterday.

High temperatures have a wide standard deviation between models (± 4.4º) but with that large spread the high of 78-79º in the city is possible.

12z NBM highs + standard deviation at 5PM Fine Black Contours are near ground (2m) temperatures in 1º increments. (Click on image for a larger view.)

Slow clearing late Friday, in fact, most of the day looks to be quite cloudy windy and colder.

Rain Possible Thunderstorms Late Thursday into Fridayg

Posted Wednesday 03/25/26 @ 5:59 PM — A cold front will drop into our area from north to south late Thursday night, similar to our last system. Before that time, southwesterly winds will bring very mild temperatures ranging from 73º to possibly 76º on Thursday. Thursday will be mostly sunny after some early cloudiness. It will be increasingly windy.

Water Vapor with RAP model MSLP and radar at 6 PM (Click on image for a larger view.)

Rain moves in from the west and as the front drops through from the north about 10-11 PM and continues through a large part of Friday morning. Heavy rain is possible with some areas seeing in excess of 1″. Like our last system, there will be very low CAPE, so any storms will be driven by high kinetics- wind shear and helicity. Most of the heavier activity will stay to our far west, possibly affecting Berks and Lancaster counties and areas to our southwest in Maryland.

More about severe potential Thursday morning.

Posted Monday 03/23/26 @ 1:31 PM — Finally, some RRFS data is available. Clouds won’t clear until this evening. The forecast light rain and drizzle seems correct and is ending around Philadelphia at 2 PM or so.

Originally Posted Mon 8:37 AM —Low pressure today (Monday) will move off the northeast. Clearing will be slow with plenty of low clouds through early afternoon. We may see some brightening and breaks of sun at times mid afternoon onward.

High pressure will be with us Tuesday through the beginning of Thursday. Then, a frontal system very similar to what we had on Sunday will drop south late Thursday into Friday with low pressure again forming just south of us.

The weekend looks good!

I’m still waiting for the reappearance of new RRFS model data, which disappeared from the NOAA-AWS repository on Friday morning. Could it be moving to “parallel” operational status on NOMADS soon? (Or could they be delaying it for version 2 with MPAS geometry?) No update is available.