We’re entering the climatologically hottest summer period for Philadelphia this week and weekend;  the current GFS forecast appears on track to support that climate statistic.

The remnants of Tropical Storm Barry are expected to bring heavy rains Wednesday night, although the exact placement is always difficult to determine.  The current GFS bullseye is right over Philadelphia.

After that time, oppressive heat and humidity is expected for much of the end of the coming week.  Temperatures and heat indices get possibly extreme on Saturday, where temperatures in some areas may approach 100, according the latest GFS.  (That’s temperature, not the Heat Index. Heat indices will be higher. )

Here’s the current GFS forecast for Saturday afternoon, about 2:45 PM:

The forecast specifics may change, but the weather will likely be very hot and humid for Thursday, Friday and especially Saturday.

A front may move through Sunday, reducing temps and humidity.

A cold front will gradually move through later today (Thursday) and tonight.  It may be slow to move out Friday morning areas east of the city.

Showers and thunderstorms will accompany the frontal passage, indeed, they have already started around noon in some areas in the city.

[su_note note_color=”#d9f2da”]What’s interesting is that most (but not all) of last night’s models didn’t have showers moving through early and had delayed them until late afternoon or evening today.

Strangely, last night’s RAP model (RAPid Refresh) was the only model to show the early showers and thunderstorms we had today and this afternoon. Even last night’s HIREF was slow to move the showers in today.[/su_note]

High pressure will build in for Friday, Saturday and Sunday.  Sunny skies and somewhat above average temperatures expected.  Daytime highs about 90 in the city.

The track of Tropical Storm (or Hurricane) Barry is still uncertain.  It’s also unclear where all that tropical moisture will end up.