Philadelphia Weather Outlook

THIS WEEK’S WEATHER

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Friday Forecast and the Weekend Preview

Posted Thursday 11/06/25 @ 7:51 PM — A cold front will approach and move through after midnight Friday into the predawn hours of Saturday morning. Friday will be cloudy in the morning, becoming sunny through high cirrus clouds by noontime. Clouds will return mid to late Friday afternoon into the evening with rain showers after midnight. It will be quite WINDY on Friday. Rainfall generally less than 0.20″

Saturday looks to be sunny, breezy and quite nice.

Another slow but sharp cold front approaches Sunday. Low pressure develops along the front bringing rain by Sunday afternoon into the night. An additional wave of low pressure may extend the rain into early Monday morning. Rainfall may approach 1 inch.

A highly amplified jet stream caused by an influx of cold air will bring winter-like cold late Monday into Tuesday. There will be snow near the Canadian border and northward.

Today’s 18z ECMWF-AI model shows an extremely sharp, amplified jet flow on Monday as captured by the RED 500-1000mb Thickness line. (Click on image for a larger view.)
Wednesday Night and Thursday

Posted Wednesday 11/05/25 @ 7:46 PM — The cold front is expected to arrive here in the immediate Philadelphia area around 10-11 PM, earlier north and west, with strong wind gusts and a broken line of showers. From 0.00″ – 0.04″ of rain expected in our area.

Update- 8:20 PM : latest RRFS just available shows greater rain coverage between 10 PM and 1 AM. Amounts~ 0.10″

7:35 PM Radar and MRMS radar with superimposed RAP model 700 mb wind streams (green) and low level vertical velocity pressure (yellow- Omega). Moderately strong dynamics but low on moisture. (Click on image for a larger view.)

Earlier today, signs of the approaching front were visible in the wavelike cirrocumulus undulatus

Cirrocumulus Undulatus about 3:45 PM associated with the instability of an approaching front. As a kid with just a barometer and a wind vane, cloud types were an important part of creating a ‘forecast’. I could never have imagined the technology we have today.

With the frontal passage, temperatures will be about 10 degrees colder on Thursday. Windy with sunny skies.

Another front Friday night will again bring little in the way of precipitation.

A storm is expected to form over us on Sunday with moderate rain ahead of a strong cold front that will bring morning temperatures by Tuesday below freezing.

Wednesday Forecast

Posted Tuesday 11/04/25 @ 6:02 PM — A “dry” cold front will move through Wednesday evening. Prior to this frontal passage, some cloudiness will move in during Wednesday afternoon. The main impact of this front will be windy/gusty conditions in the afternoon and especially Wednesday evening.

12z RRFS Wind/Gusts meteogram for KLOM Wings Field, Blue Bell. The arrow points to the expected actual frontal passage, about 8-9 PM. Wind gusts approaching 35 mph. (The 18z HRRR shows wind gusts near 50 mph).
Wednesday & Friday & Sunday Night Cold Fronts

Posted Monday 11/03/25 @ 7:58 PM — Following very typical sunny weather on Tuesday for early November, the following days (nights actually) will feature a series of cold fronts moving through Wednesday night, Friday night and Sunday night.

Wednesday’s cold front will have much of the rain pass us to our north.

18z ECMWF-AI -Thursday 1 AM – cold front has moved through. Much of the rain has remained to our north. (Click on image for a larger view.)

Friday night into Saturday looks to have a wetter cold front passage with likely clearing in time for much of the day Saturday. Yet another cold front on Sunday night will usher in a brief period of very cold weather with temperatures likely below freezing by Tuesday morning.

Monday Forecast Update

Posted Monday 11/03/25 @ 8:59 AM — The latest NAM-NEST has joined the other models forecasting minimal to zero rainfall from the city westward today. Here’s the current water vapor image—

Water Vapor Satellite image with superimposed HRRR pressure and 3 hour pressure change. Low pressure off the coast of NC will move northeastward. Drier, warmer air to our south will move in during the afternoon hours. (Click on image for a larger view.)

While there’s still a chance of a few widely scattered sprinkles late morning, most areas will see clearing skies from west to east during the afternoon. Here’s the GFS cloud cover forecast for 3 PM today—

06z GFS cloud/precip forecast for 3 PM. (Clouds are black/grey) (Click on image for a larger view.)
Monday Forecast

Previously Posted Sun @ 8:11 PM — —As mentioned over the weekend, there’s been uncertainty regarding coastal system that may bring rain into our immediate area.

Sundaty 6:30 PM Current satellite water vapor image with superimposed RAP model 500-1000 mb thickness lines (yellow), Mean Sea Level Pressure isobars (black contours) potential vorticity (fine violet contours) with superimposed MRMS RADAR. Water Vapor Imagery reveals emitted water vapor infrared temperature, NOT reflected light from clouds as is the case with visible satellite imagery. (Click on image for a larger view.)

There’s been relative continuity in the forecasts about rain/showers affecting the Jersey Shore and only somewhat inland. Here’s the ECMWF-AI forecast light precipitation extending almost to the city:

ECMWF-AI total rainfall Monday. The total rainfall will be very light near the city with none westward. (Click on image for a larger view.)

Of interest is the latest NAM-NEST, which has a band of precipitation into the immediate PHL area. (I should state that the NAM-NEST is an outlier forecast compared to the other models) —

Today’s 18z NAM-NEST which has considerable rain for our immediate area. (Click on image for a larger view.)

Based on my comparison of current (RTMA) and forecast conditions, it would not surprise me if the NAM-NEST is correct tomorrow.

Unfortunately, the RRFS and REFS have not been available this weekend. The government shutdown is the likely reason. I would have leaned in their direction for this forecast.