With all the thunderstorms that have moved through Philadelphia this afternoon and evening, there are areas to the immediate northwest that have barely gotten anything.

Showers and thunderstorms should continue tonight, ending before daybreak.

Sunday should look today, with a mix of clouds and sun. Essentially dry for much of the day.  An easterly wind will make things much cooler with a high of about 67.

Clouds increase late in the afternoon with showers developing late afternoon.


I thought it was going to rain?  Me too!  So what’s with the forecast?

Last night’s NAM data (which comes out later, between 10 and 11 PM due to daylight savings time), showed some changes with the forecast and I tried to patch my forecast with a quick update at 11 PM.  I failed to fully examine the changed humidity fields— which showed this sunshine for the morning hours today.

So the models continue with some sun and essentially dry conditions for this morning .  Things change after 12PM  today,  as low pressure develops to our south and things become more unstable.  Scattered thunderstorms can form almost any time after 12 PM today and the probability increases considerably during the late afternoon.

Afternoon simulated radar
HRRR 4PM Saturday simulated radar forecast

Like last Saturday, these storms will not move in as a line, but will develop in place and be slow movers.  Most areas will have had showers and thunderstorms by 6 pm, although the areal coverage won’t be large at any one time.

The chance of showers persists into the evening.