E PA/NJ/DE Autumn 2026 Obs/Discussion

[JTA66]

Not sure, but I think I just heard thunder.

[pl0k00n111]

Yes thunder in pennsauken nj, a short burst of heavy rain. 

[ChescoWx]

Extended Ensemble outlook (not a forecast) shows a cooler trend than normal for last week of October and into the first couple weeks of November.

 

[ChescoWx]

Not much rain this AM 

[ChescoWx]

How does the ChescoWx East Nantmeal forecast stack up against the National Weather Service? After 7 weeks of scoring every forecast against what actually happened, the temperature results are pretty clear!

Since August 22 we have verified 50 days and about 2,800 high and low temperature forecasts, each one matched up against the NWS forecast for the same day issued at the same time.

ChescoWx was closer on temperatures on 45 of the 50 days. The NWS was closer on 4 and 1 was dead even.

The typical ChescoWx miss was about 1.8 degrees. The typical NWS miss was about 3.0 degrees.

For tomorrow's forecast the gap is widest... about 1 degree for ChescoWx vs about 2.5 degrees for the NWS. The edge holds out through day 6 and the two are basically even by day 7.

About 8 in 10 ChescoWx forecasts landed within 3 degrees of the actual temperature vs about 6 in 10 for the NWS. Much of the NWS gap is a warm lean on daytime highs of about 3 degrees in our backyard.

Rainfall is a different story. On the 10 days with measurable rain the NWS did a bit better, and both forecasts badly missed our two biggest rain events (1.66" on September 3 and 2.42" on October 11). Rain is where we are focused on improving next.

Fair caveat... 50 days of late summer and early fall is a start, not a final verdict. We will keep scoring every forecast through the winter, and snow will be the real test!

The live scorecard is on the Current Weather page here:
https://chescowx.com/current-weather/

Let me know if any questions!

[JTA66]

Slight risk day 2 west of the river. We'll see. 

[ChescoWx]

Of note 72 years ago today back in 1954 Chester County was on the last day of a 2 day storm that left as much as 1.60" of rain at Coatesville 1SW. This was the remnants of Hurricane Hazel which tracked within about 80 miles of the county. Today we should see highs in the upper 60's to near 70 which is about 5 degrees above normal with lows tonight in the 50's. Temperatures will run about 11 degrees above normal Friday but by Saturday we drop to 4 to 9 degrees below normal, before we return to near normal by Tuesday. By Sunday morning lows will be in the low to mid 30's with a freeze possible in the colder valleys! Our best chance of rain is Friday with around 0.30" according to the ChescoWx model.