Saturday Noon Update: Heavy rain is falling around the shore in NJ at this hour and much of the activity was east of PHL this morning. Sunshine has broken out in PHL (more than forecast) and the rain in PHL was over-forecast for the morning.

Current short-range analysis has a significant bullseye of deep moisture convergence in the immediate PHL area.

Mesoscale Analysis 12 PM -Deep Moisture Convergence (RED contours)

Showers and thunderstorms should re-develop this afternoon in the immediate PHL area.  

A wet Saturday appears to be a certainty, as even the NAM has joined the other models with significant rain. The details were outlined in this morning’s early edition post.

Rain and showers are expected on or before daybreak Saturday and should become heavier in the afternoon.  It will be warm and humid with highs near 83 and dewpoints in the 70s.

There’s still some uncertainty about the amount of rain and showers on Sunday, but the current thinking is that showers will be more widely scattered with more breaks than Saturday. Highs near 85 and continued humid.

That said, the latest GFS shows quite a bit of rain for Sunday.  I’ll need to update over the weekend.


A wet scenario will setup for this weekend. It’s a setup we’ve seen several times this summer season— an upper low pressure system is expected to close off to our west and a stream of moist unstable air will flow into our region.

Showers and thunderstorms are possible Friday evening, but the models have increasing chances of showers and thunderstorms throughout the daytime hours of Saturday into Saturday evening. Some of the showers could be heavy.

The skies will be mostly cloudy on Saturday, although some breaks or brightening skies are possible, especially mid-day hours. Highs about 81 with high humidity.

A similar situation is expected for Sunday, although the shower activity is expected to be lower than Saturday. Brighter skies and some sunny breaks possible on Sunday, but widely scattered showers possible any time, especially later in the afternoon.  High again about 81,

Regarding forecast confidence, the GFS, ECMWF and the NBM are in good agreement. The NAM is significantly less robust with the shower coverage, especially for Sunday.  I’ll update later.