#Philadelphia #weather #PAwx #PhillyWx
Thursday through Friday
Posted Wednesday 05/14/25 @ 5:28 PM —Following some scattered showers Thursday morning, many of us may finally see some sun Thursday by mid afternoon. Unfortunately the upper air will be cold and thermal instability will lead to scattered showers and thundershowers between 2 and 6 PM. A mix of clouds. sun and scattered storms sums it up for the afternoon.
Friday, a strong impulse rotating around the upper low near the Great Lakes will result in potentially some strong fast moving storms here around noon. Here’s the RRFS, which suggests a bow-echo formation around noon—
The potential for damaging winds Friday with this impulse needs to be watched.
Posted Wednesday 05/14/25 @ 12:14 PM — Opted against going to the afternoon Phillies game. The morning models support a dry slot developing, and current radar/water vapor imagery shows dry slot advancing northward—
The hold-out for improving conditions is the experimental RRFS. It still shows some showers during the afternoon game. (Perhaps we’ll see why it’s still ‘experimental.)
What about the Phillies Games today?
Posted Wednesday 05/14/25 @ 9:10 AM —It does look like there will be a relative ‘dry slot’ develop beginning about 2-3 PM today in the city. The latest HRRR (11z) shows rain exiting to the northwest.
Here’s the simulated radar forecast for 1 PM. There may be some showers at the scheduled game start—
The latest HREF model, which is a statistical ‘ensemble’ of the HRRR, NAM-NEST and RAP models shows minimal rain for the hour preceding 2 PM —
Additional rain is expected during the evening, but the models are leaning towards it being somewhat west of the city.
As for total rainfall so far for this event, this has been the most significant widespread rainfall we’ve had in a long time. Here’s the latest 48 hour total estimate—
Wednesday Forecast Update
Posted Tuesday 05/13/25 @ 5:19 PM — The weather is unfolding as forecast, with a stream of increasingly heavy showers moving up from the south southeast around a closed upper low to our west.
The latest ECMWF-AI model has rain continuing tonight and becoming quite heavy by early morning Wednesday. Some thunderstorms may be in the mix on Wednesday. A total of almost 2″ of much needed rain is forecast for our area through midnight Wednesday.
It looks like some rain/showers continue on Thursday as the upper trough axis moves over us. Thunderstorms also possible.
Tuesday Forecast Update
Posted Monday 05/12/25 @ 5:56 PM — The forecast appears to be generally on-track with rain expected in the immediate Philadelphia area on or before 5 AM Tuesday morning.
Here’s the current satellite water vapor image—
Light showers to start, then bands of heavier rain move in later in the morning and continuing, with some breaks, through the afternoon and Tuesday night. Rain tapers off somewhat on Wednesday, but thundershowers will likely develop during the afternoon.
Total rainfall around 1 inch possible in and around Philadelphia, by Wednesday morning. more west of the city.
Posted Monday 05/12/25 @ 7:40 AM — This week’s model forecasts continues to evolve, with a shift towards some heavier rain in the immediate Philadelphia area by Wednesday. (I’ll have to see it to believe it.)
For today, sunshine through high cirrus clouds, with clouds thickening between 4 PM and 7 PM from southwest to northeast. Rain begins here before daybreak Tuesday, but much of the rain will be showery in the morning.
The chance of more moderate to heavy rain waits until later on Tuesday and most likely Tuesday night into Wednesday morning.
Originally Posted Sun 8:17 PM —Monday will have sun through high clouds, then increasing cloudiness by 4PM. High temps similar to Sunday, near or just above 80º. Rain begins after midnight early Tuesday morning.
An active weather week ahead, where another upper level closed low will bring good chances for rain from before daybreak Tuesday through Friday.
Despite this forecast, it’s not entirely clear whether the needed heavier rain will be in and around Philadelphia, or continue a long standing pattern for the heavier rain to remain to our far north and west. Some models are showing heavier banding right over Philadelphia, but others (Canadian and various runs of the German ICON model and the RRFS) show the heaviest rain to our far northwest.
The latest GFS shows this west-northwest trend—
Some models show just intermittent showers on Tuesday, while others are forecasting periods of moderate, continuous rainfall here. Too early to be sure.
There will also be the possibilities of thunderstorms during the week; the higher dew points, available moisture aloft and instability will set the stage for these storms, especially late afternoons and evenings.
Stay tuned.
