Daily Archives: Sunday, October 12, 2025 5:49 pm

Philadelphia Area Weather Forecasts

THIS WEEK’S WEATHER

#Philadelphia #weather #PAwx #PhillyWx

Quiet Weather through Most of Sunday

Posted Thursday 10/16/25 @ 7:47 PM — Not much happening weather-wise over the next three days. Cold front in upper midwest will slowly advance towards us. Warmer flow of air ahead of the front will bring
temperatures into the low 70s by Sunday.
Showers associated with this front will likely waituntil Sunday evening (6-10 PM) before moving into the immediate Philadelphia area.

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.)

Rainfall with the front late Sunday evening through around daybreak Monday will be light. The NBM shows rainfall totals of 0.3″-0.5″

18z NBM total rainfall by Monday Black Contours are 0.1″ spacing. (Click on image for a larger view.)
Wednesday-Sunday

Posted Wednesday 10/15/25 @ 8:31 AM — High pressure at the surface and an upper level ridge builds in for the next several days, giving us beautiful Fall weather. On a more granular level, an upper level jet streak moves through later this morning (Wednesday); some models have a brief period of cloudiness here, some don’t. A difficult call.
Temperatures are expected to be in the upper 60s and maybe low 70s.

Earlier this week, it appeared that some near-80º temperatures would be with us Sunday. That’s no longer the call, but still mild in the low 70s. A strong cold front moves through Sunday night into Monday morning with some rain. The Eagles game will see nice weather, but it may be windy ahead of the cold front.

ECMWF-AI forecast for Sunday at 8 PM

Tuesday -Wednesday

Posted Monday 10/13/25 @ 5:33 PM — Plenty of clouds on Tuesday with some brightening possible mid to late afternoon. We’ll finally see the sun on Wednesday. It will be windy both days. Tuesday high 67º Wednesday high 67º-69º

Forecast Review
Mon 4:50 PM —Forecast Review — The storm isn’t over yet, but a number of things stand out— the forecast wind gusts and rainfall accumulation were much lower in magnitude than originally forecast in and around Philadelphia.

What looked to be a drought buster was simply a bust as far as meaningful rainfall. Of course, a different story at the NJ Shore which was was more accurately forecast.

While the storm is not over, here’s the multi-day total of actual rainfall—

4 PM – MRMS rain-gauge measured rainfall combined with rain-gauge calibrated and interpolated radar-based summary of ACTUAL RAINFALL RECEIVED. Color shading is in inches. Line contour numbers are in mm. (25.4 mm= 1 inch)      (Click on image for a larger view.)

The current radar around 4:30 PM shows what’s been happening for the past two days: rain drops along the coast and there’s not enough lift and dynamics to continue the rain inland—

Radar image with superimposed RAP model maximum Omega (vertical motion). The rain doesn’t make it much past I-95. (Click on image for a larger view.)

You might ask why? While there’s a surface low and even a mid level low over our area, the upper air (jet level) is anticyclonic in shape and the I-95 corridor lies in an area of descending air from the jet streak to our west. Here’s the RAP model output that demonstrates this—

Jet stream level winds (colorized) with white arrows The red rectangle is an unfavorable location for the upper motion needed for rain. The fine concentric blue contours are favorable areas. (Click on image for a larger view.)

Forecast Update

Posted Sunday 10/12/25 @ 10:05 PM — For Philadelphia and westward, very light rain overnight. Somewhat light to moderate rain moves in from the southeast about 10 AM Monday and tapers off around or after midnight Monday into Tuesday. For the NJ Shore, moderate rain tonight becoming heavy again Monday with high winds.

18z REFS probability matched mean precipitation. (Click on image for a larger view.)

Originally Posted Sun 5:49 PM —This week’s weather picks up where the weekend’s coastal system left off. Heavy rain and high winds have been battering the New Jersey Shore, but as forecast here last night, the amount of rain inland, from the I-95 corridor westward, has been minimal.

The coastal low has elongated and split into two systems, notably forecast by the ECMWF yesterday—

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.)

The northern system will intensify and bring rain and winds further inland tonight and especially Monday.

Here’s the current conditions using the RTMA. I’ve drawn the track of the two lows based on the ECMWF forecast—

5 PM RTMA wind streams with 3 hour surface pressure tendencies. Track of the lows is based on the ECMWF. (Click on image for a larger view.)

The models continue to over-forecast rainfall for the immediate Philadelphia area and west of the I-95 corridor. The latest model forecasts range from 0.20″ to 0.50″ rainfall by daybreak Tuesday morning. I’m leaning towards the lower range for most locales based on the RRFS which correctly forecast the paucity of rain we had here today.

Winds will continue to increase.

Winds and Gusts Meteogram for Blue Bell PA

This is an interesting storm. Check back for updates.