Category Archives: Philadelphia Area Weather Forecasts

Philadelphia Area Weather Forecasts

THIS WEEK’S WEATHER

#Philadelphia #weather #PAwx #Drought

A Few Drops of Rain

Posted Friday 11/01/24 @ 8:17 AM — I set up today’s forecast as a “model test”, with the ECMWF consistently forecasting some light shower activity and the GFS moving through with no showers.

We have light shower activity moving through, as forecast by the ECMWF—

MRMS radar image 7:45 AM. Very light showers, likely not exceeding 0.01 or 0.03 inches. (Click on image for a larger view.)

Today’s front will take time to move through and we’ll continue with mild temperatures for Friday. Cooler, more seasonable air doesn’t filter in until Saturday.

The ECMWF-AIFS model continues to show a hurricane moving towards the Gulf Coast next week. The track has trended a bit further westward. Here’s the latest forecast for next Friday—

11-01-24 06z ECMWF-AIFS forecast for next Friday. (Click on image for a larger view.)

The GraphCast GFS AI forecast doesn’t show this, but the operational German ICON model consistently does.

While not a sure thing, the track of this storm may be enough to break our dry weather pattern.

Another Hurricane?

Posted Thursday 10/31/24 @ 4:45 PM — The latest ECMWF-AI has become available. Here’s its forecast for next Friday—

10-31-24 12z ECMWF-AIFS forecast for next Friday morning (Click on image for a larger view.)

Not a good thing for the Gulf Coast, but we may eventually get some rain from this system .

Model Test for Friday

Posted Thursday 10/31/24 @ 2:56 PM — No significant change in the forecast for Friday; the ECMWF continues to spit out some light sprinkles in the mid morning hours while our GFS has us cloudy but dry.

An “interesting” development: The extended range forecasts are beginning to show a strong signal for another hurricane to develop in the Gulf of Mexico and for it to move northward along the western coast of Florida next week. (Updated- possibly westward into Texas) The ECMWF-AIFS, which had been so skillful forecasting Milton, is showing this storm, as is our GEFS, Also of interest is the German ICON model, which has been showing distinct development for a couple of days, somewhat before the AI models—

10-31-24 06z German ICON model forecast for 10 PM Monday (Click on image for a larger view.)
One More Thing

Posted Wednesday 10/30/24 @ 9:00 AM — The near 80° temperatures for Halloween have been well-advertised. One more thing: it looks like it will be quite windy and gusty on Thursday and even more so Friday.

An Interesting Test for the Models

Posted Wednesday 10/30/24 @ 8:29 AM — I think we’d all like to see a little rain on Friday with the upcoming cold front passage. As we all know from recent months, any shower activity to our west has dissipated as it moved eastward through Philadelphia due to persistent blocking high pressure.

Current NOAA model forecasts are showing the same highly diminished rainfall. The same as true from the Canadian models.

Interestingly, the ECMWF and German ICON models have been consistently showing a line of showers moving through Philadelphia late Friday morning—

ECMWF forecast for 11 AM Friday morning (Click on image for a larger view.)

This shower forecast has been supported by the ECMWF-AIFS model but not the GFS AI model (Graphcast GFS). It will be interesting to see how everything plays out. We could use the rain.

Update

Posted Tuesday 10/29/24 @ 9:36 AM — As mentioned in my earlier post today, the conditions conducive to rain here next week have disappeared from the latest extended range and AI models. In fact. it’s hard to imagine a more accentuated upper level ridge over us that impedes development of rain—

ECMWF-AIFS forecast for next Tuesday. Incredible upper level ridge over us! (Click on image for a larger view.)
Hoping for Rain

Posted Tuesday 10/29/24 @ 8:40 AM — Our current very dry period is not going to go away easily. A cold front moving through Friday morning into the afternoon had been promising to bring some showers. The latest GFS and GEFS have backed off considerably on that promise, although the ECMWF is still showing some light shower activity Friday morning. The AI models are showing very light shower activity, but the trend is towards little rain. The model blend (NBM) has trended towards no showers.

On top of that, the unsettled, possibly rainy period that’s been promised for the first week in November is also looking less of a sure bet.

Temperatures still look incredibly warm for Halloween. The latest NBM has moved back towards the low 80s in many areas!

NBM high temps for Thursday
Increasingly Warm

Posted Monday 10/28/24 @ 9:30 AM — Increasingly warm temperatures expected through Thursday. The NBM has backed off on some of the 80º temperatures a bit with much of the region in the upper 70s.

10-28-24 12z NBM high temps Thursday. Most models in the mid to upper 70s. (Click on image for a larger view.)

An increasing signal for some showers with a cold front early Friday (GFS) or afternoon Friday (ECMWF). Maybe 0.10 to 0.20″ rainfall, although still not a sure bet in all areas.

Originally Posted Sun @ 7:14 PM — —An upper air ridge will build through Thursday, bringing us sunny skies and increasingly warm temperatures. Indeed, temperatures may approach or exceed 80º on Thursday, Halloween.

10-27-24 18z NBM high temperatures for Thursday, Oct 31. (Click on image for a larger view.)

High pressure moves off late Thursday, as a cold front brings a chance of some showers here—

NAEFS forecast for Thursday 2AM High pressure still in control. (Click on image for a larger view.)

Any showers we receive after midnight Thursday into pre-dawn Friday morning will be light, less than 0.25 inches according to the latest GFS. It should be noted that the ensemble models and the AI models show even less rain here in Philadelphia, perhaps very little, during this cold front passage.

For those hoping for some rain, things still seem somewhat optimistic for some rain here during the time frame Monday Nov 3rd through Thursday Nov 7th. Stay tuned.

Philadelphia Area Weather Forecasts

WEEKEND WEATHER FORECAST

#Philadelphia #weather #PAwx #drought

Posted Saturday 10/26/24 @ 4:45 PM — Still keeping an eye on the potential for some rain here in Philadelphia, but we’ll have to wait until November 3rd though November 6th, according to the statistical ensemble models and the GFS, ECMWF AI models.

The latest GFS Graphcast Machine Learning-AI model is the most aggressive with some rain and low pressure development—

GFS-GRAPHCAST AI model forecast for Monday Nov 6th.

The latest ECMWF-AIFS is less aggressive with low pressure development and rainfall here—

ECMWF-AIFS forecast for Monday November 4th. Of interest is possible tropical development near Cuba. Some of the ensemble models show moisture from this tropical development moving up the coast towards us. (Click on image for a larger view.)
An interesting article in today’s Washington Post on AI weather models —

“AI is transforming weather forecasting. Is the U.S. falling behind?“

Originally Posted Fri @ 5:41 PM — —Our dry sunny weather continues…

A cold front will make a dry passage through the area tonight. It will take some time for the cold air to filter in, so Saturday will be in the mid 60s and temperatures drop into the mid to upper 30s Saturday night.

Sunny skies will continue Sunday with highs dropping to the upper 50s to near 60º in some spots. Cold temperatures Sunday night before things warm up again into next week. Indeed, we may see temperatures near 80º on Halloween!

With so little happening weather-wise in the short term, I’ve been checking the extended range models and newer AI models for any signs of some rain here, Our next chance of any rainfall appears to be between November 2nd and November 5th. Some of the extended statistical ensemble models hint at some unsettled weather during this period and perhaps a pattern change.

Here’s the latest ECMWF-AIFS forecast for Sunday, November 3rd—

10-25-24 12z ECMWF-AIFS forecast for Sunday November 3. A cold front moves through. Much of the heavier showers stay to our northwest, but there are signs that low pressure may form along the front, giving us more rainfall during the following days. (Click on image for a larger view.)