Sat 08:20 AM Update —The current GFS model has it a bit hotter (95º Blue Bell) but dew points much lower, in the low 50s, today. The model blend (NBM) maintains a high today of 93.3º sd 1.3º with dew points near 61º.
A typical July hot weather pattern with a Bermuda high and a southwesterly flow of air will be with us over this weekend.
It will be sunny and dry both days.
High temperatures 93.5° sd 1.7° on Saturday and 96.5° sd 2.1° on Sunday.
Some fog likely early Sunday morning in NJ.
The latest GFS model keeps dew points in the relatively comfortable upper 50s on Saturday (during the afternoon) and in the more uncomfortable mid 60s on Sunday in the afternoon. Winds will be light.
The model blend (NBM) keeps the heat index in the high 90s on Sunday.
Fri 12:48 PM Update — Today’s models continue with the forecast of temperatures in the 90s (Saturday 93º) Sunday (96-97º) but dew points will slip back into the 50s for Saturday and mid 60s for Sunday during these peak temperatures in the afternoon hours. That’s different than what you’re hearing from the TV weather entertainers.
A weak frontal system will move through late Friday with some very light widely scattered showers preceding the frontal passage. A few areas might have a heavy thunderstorm.
As mentioned earlier in the week, we are transitioning from an upper air trough pattern to more of an upper air ridge pattern this weekend. A Bermuda High will pump in hotter and more humid air. (The ridging predicted earlier in the week will be less pronounced than previously thought.)
SREF model forecast for Sunday 12 PM (Click on image for a larger view.)
This afternoon’s models have continued to forecast temperatures in the 90s for Saturday (93º) and Sunday (96º) afternoon. Here’s the current NAM temp forecast for Sunday—
NAM Sunday 3 PM Forecast High Temps (Click on image for a larger view.)
At the maximum heat of the day, dew point temperatures above 70º will be south and west of the immediate PHL area.
So with the high July heat, there will be no corresponding increase in water vapor; relative humidity and dew points will correspondingly drop to the somewhat less oppressive 60s during the maximum heat of each afternoon in our immediate area—
NAM Forecast Dew Point Temperatures Sunday afternoon. (Click on image for a larger view.)
Little or no chance of rain over the weekend.
As is often the case, dew points will increase at night, so it will be very humid during the evenings and night time hours. Some fog is likely in NJ Saturday night and early Sunday morning.
