Category Archives: Weather Updates


Latest models show high temps about 51-52 Sunday afternoon (based on NBM and EDKMOS).    Over the weekend, I kept hearing about “cold, windy” conditions during the Eagles game.  Breezy, maybe, but winds are forecast to be about 7-9 mph with gusts to 13  — a rather routine wind profile.


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Update: Sun AM  — The models still indicating a faster moving system.  Frontal passage about 12-1 PM  with high wind gusts.  Total rainfall (QPF) has fallen to about 0.5 inches or so, more far north and west.  Clouds break for some sun, possibly as early as 3-4 PM.   High temps near 74!  
Update:  Simulated Radar, clouds and pressure for 2 PM  from this morning’s high resolution WRF-ARW model—

WRF-ARW high resolution simulated radar depiction for Sunday 2 PM showing rain east of Philadelphia

Rain ends and clouds clear early to mid afternoon.

from last night:

As mentioned yesterday, only the statistical models suggested the possibility of light showers (that occurred) Saturday afternoon.  Looking back at this morning’s models, only the NAM Nest model showed the showers. I don’t think I would have changed the forecast based on that one model.  It’s interesting that the other models really didn’t pick that up.

Speaking of today’s models, the timing for tomorrow’s rain has changed somewhat— the rain moves in earlier on Sunday: 5-8 AM and tapers off between 2-4 PM. We may even see some sun late in the afternoon tomorrow.  Rain QPF is coming in lower at about 1 inch or less.

The GFS is still showing high wind gusts when the front moves through late morning into early afternoon.

The cold weather I mentioned in recent posts may be delayed until next weekend. Halloween is looking very wet.


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No showers developed Philadelphia and west, as expected. There were some thundershowers in south Jersey, not as much areal coverage as predicted by the models last night. Dew points were delightfully lower than had been predicted.  

Pop-up, widely scattered thundershowers did develop today (Saturday), but the areal coverage was hardly close to the model precipitation forecast graphics that I posted yesterday. (This morning’s models which came out after 10:45 am had actually cut back on the showers for today.)

Tonight’s model forecast just becoming available shows even fewer showers for the immediate Philadelphia area westward, but a weak frontal boundary passing through sparks some thundershowers, mostly from the city eastward into N.J. mid to late afternoon.

Current WRF 1hour accumulated rain forecast Sunday 4:30 pm

As we’ve seen today, prediction of specific areal location of thundershowers is something models attempt to do with limited and inconsistent success.

Except for these showers, Sunday will be mostly sunny, very warm and somewhat humid— typical August weather. High 87-89.



There are interesting differences in last night’s models regarding the chance of showers/thundershowers this evening. (Sunday evening)

An upper air disturbance drops down into our area this evening, between 7PM and 1 AM.  The NAM has been consistent in keeping any showers far to our north.  One version of the WRF with NAM physics (WRF-NMMB) also does the same.

The GFS  (and its similar physics version, the WRF-ARW) has showers and thundershowers making it in to the Philadelphia area towards midnight, then dissipating.   It will be interesting to see which model does the best here.

Either way, today will be hot and slightly more humid. Highs 91-93 with dew points near 60.