Category Archives: Philadelphia Area Weather Forecasts

Philadelphia Area Weather Forecasts

WEEKEND WEATHER FORECAST

#Philadelphia #weather #PAwx

Sunday through Wednesday

Posted Sunday 06/16/24 @ 9:23 AM — Sunny skies today with highs 87º Blue Bell and 88º Philadelphia with a average confidence level of ± 1.6º.

Looking at the latest NBM just available, forecast high temperatures for Monday through Wednesday have come down a smidgen— instead of mid 90s, the highs are closer to the low 90s.

MONDAYTUESDAYWEDNESDAY
BLUE BELL89.092.392.8
PHILADELPHIA89.793.193.6
Today’s 12z NBM model high temp forecast usually reached between 3PM and 4PM. All temps have average confidence with an sd of ± 1.5º

Higher temps into the mid 90s expected by the end of the week into the weekend.

Relief from the heat appears to come from a cold front not expected until next Monday afternoon or evening according to the ECMWF and the NAEFS. That’s eight days away and that forecast may change.

ECMWF forecast for Monday June 24th. Cold front moves through (Click on image for a larger view.)
Yesterday’s Rain

Posted Saturday 06/15/24 @ 10:32 AM — As a follow up to yesterday’s forecast review, I wanted to post the 24 hour MRMS rainfall totals. Some areas received significant rainfall while many others in our area received very little. The location and timing of the heavier rain axis was not forecast by any of the models.

MRMS combined rain gauge & radar-based measurement of actual rainfall received. Color shading is in inches. Line contour numbers are in mm (25.4 mm= 1 inch) (Click on image for a larger view.)

With the building upper ridge and heat wave expected beginning Monday, this rainfall appears to be the last until next Sunday into Monday, (June 24th) when another cold front may come through.

Posted Friday 06/14/24 @ 7:38 PM —I’ve posted an important Friday forecast review here.

Previously Posted Fri 3:59 PM —A cold front slowly moves through Friday night. The main batch of showers and thunderstorms move through to our north and to our south, with weak low pressure developing over Philadelphia about 11 PM. Some additional showers/rain towards midnight possible in the immediate Philadelphia area. Total rainfall will not be that impressive in some areas, while other areas, especially far north, may get some heavy downpours.

Everything clears out by morning for Saturday and Sunday. Sunny skies with very pleasant temperatures and low humidity for this entire weekend. A simple forecast, not needing any more details here.

The big story will be the change in pattern starting late Monday into Tuesday, with a shift to an upper level ridge and possible development of a heat dome bringing 90º+ weather here for next week and beyond. It will also be dry with no significant rainfall in the picture. The latest long range forecasts have backed off a bit on the 95º temps and have them closer to low 90s.

The NAEFS captures this change—

Today’s 12z NAEFS shows high pressure on Tuesday. Note the 576 thickness line (brown-orange contour) (1000-500m thickness) which outlines the heat dome as it extends in the central US and well into Canada and the east coast.. (Click on image for a larger view.)
Philadelphia Area Weather Forecasts

WEEKEND WEATHER FORECAST

#Philadelphia #weather #PAwx

Sunday Forecast Update

Posted Sunday 06/09/24 @ 8:41 AM — Few of last night’s models captured this small line of showers moving through early this morning.

Line of light showers (1) moving northeastward at 8 AM, not forrecast by the HRRR, NAM-NEST or RRFS. Line #2 of showers is forecast to move through between 1-3 PM today. A mix of sunshine and clouds before and after. (Click on image for a larger view.)

Posted Saturday 06/08/24 @ 4:40 PM — It could not have been a nicer day on Saturday.

There are some timing changes for the weak frontal passage and light showers possible on Sunday.

Today’s models have moved these showers to the morning hours. Scattered, light showers possible as early as 9-11 AM. Somewhat heavier showers far northern suburbs. Additional lighter scattered showers possible 2-3 PM. Not everyone will see a shower. In fact, there’s a wide range of model forecasts with some models showing almost no shower activity here.

Saturday’s 18z NAM-NEST cloud/rain forecast for 11 AM Sunday. The NAM-NEST is more robust with the showers than the HRRR and may be over-done.) (Click on image for a larger view.)

Cloudy in the morning, a mix of clouds and sunshine during the afternoon Sunday.

No significant rainfall this coming week. Increasingly warm (hot) by the end of the week. By next weekend, eyes will turn to the Gulf of Mexico and Florida where some tropical development is suggested by the extended range models.

Previously Posted Fri 4:48 PM —Our area remains under the influence of an upper level low in Canada and a cool flow around this low. Daytime heating will result in some instability cloudiness, but most of the Saturday will be sunny.

Current satellite water vapor image (Friday afternoon) with superimposed RAP model 500-1000 mb thickness lines (yellow), Mean Sea Level Pressure isobars (black contours) potential vorticity (fine violet contours). Cool circulation around the upper low in Canada will be with us. (Click on image for a larger view.)

By Sunday, a weak disturbance and weak cold front moves through, bringing a bit more cloudiness and the chance of very light scattered showers in the afternoon.

ECMWF forecast for Sunday at 5 PM shows a weak disturbance with some light showers, especially South Jersey late afternoon. (Click on image for a larger view.)

Saturday

Partly to mostly sunny. Still somewhat cooler than seasonal average temperatures. Highs 80º (Blue Bell) to 83º (Philadelphia)

Sunday

Partly cloudy/Partly Sunny. A chance of light scattered showers during the late afternoon, mostly in South Jersey. Highs 81º (Blue Bell) 84º (Philadelphia)