#Philadelphia #weather #PAwx

Sunny Skies

Posted Thursday 08/22/24 @ 5:20 PM — Sunny skies with a gradual increase in temperatures through Sunday. Here’s the latest NBM temp and dew point forecast in the form of a meteogram —

First chance of any precipitation, may be Monday, late afternoon or evening.

Quiet Week Weather-wise

With an upper trough and corresponding surface high pressure system in place, our weather is spectacular, but a bit cool. (Current seasonal average highs are 82º Blue Bell, 83º Philadelphia.) We’re also seeing a bit of instability cloudiness at times.

As for that storm that threatened on Monday, here is a photo of what looks almost like a shelf cloud associated with a thunderstorm just northwest of my home at 6:30 PM Monday—

Forecast Update

Posted Monday 08/19/24 @ 8:47 PM — Well, a wave has developed on the front and some showers are expanding in coverage just northwest of the city. Apparently predicted by the NAM-NEST and the HRDPS. May move in over the next hour. Very interesting.

Posted Monday 08/19/24 @ 4:37 PM — Today’s forecast line of showers and thundershowers fell apart and went to our north and to our south. Current radar shows some other activity but winds have shifted and I wouldn’t count on any significant showers in the immediate Philadelphia area. Here’s the current radar at 4:30 PM—

For the balance of the week, an upper trough will allow cool high pressure to build in through the weekend. Sunny skies and unseasonably cool weather is expected for the next several days. The NAEFS shows the forecast jet stream position on Thursday—

Mostly sunny and dry through the week. The upper low can cause some instability cloudiness at times, especially in the afternoons and some difficult to time disturbances may rotate around the upper low. But overall, quite nice for an extended period of time.

Just speculation, but I expect the heat dome to return by the end of August or the beginning of September.

Monday Forecast

Originally Posted Mon 8:41 AM — A strong cold front will move through our area late this afternoon preceded and accompanied by showers and some thunderstorms. Gusty winds expected but severe weather not expected at this time.

Prior to the showers/storms, expect some sunshine.

Current timing is between 4 PM and 8 PM. Here’s the RRFS simulated radar forecast for 4 PM—

#Philadelphia #weather #PAwx

Friday-Saturday-Sunday Weather Outlook

Posted Thursday 08/15/24 @ 5:29 PM — As expected, the forecast for the weekend continues to change. The trend is for the next system to approach slower than previously forecast. First, let’s talk about Friday.

Friday is looking sunny with high thin cirrus clouds in the afternoon. (The haze you may noticed Thursday is wildfire smoke and particulates. Friday will likely continue to have haze from smoke.) No rain.

Saturday‘s forecast has changed. Originally, Saturday was expected to have showers during the day. Now, the forecast is for showers moving into western sections late afternoon or early evening. Most of the area will be dry during the daytime. It will be cloudy early but the cloudiness will likely break for periods of sun at times. Showers and thunderstorms will move in late evening or after midnight in the city as a warm front approaches.

Sunday looks to be cloudy with showers and thunderstorms likely. The heaviest and most widespread rainfall is expected later in the day and evening into Monday. The rainfall may not reach the Jersey Shore until later in the afternoon.

I’ll fine tune with my regular Weekend Weather Forecast tomorrow.

Show More

Thursday -Weekend Weather Outlook

Posted Wednesday 08/14/24 @ 8:33 PM — The weekend forecast continues to evolve; the expected proximity of Hurricane Ernesto to our area will likely effect the accuracy of the forecasts. Tropical systems seem to change the weather in ways that the weather models don’t seem to capture correctly. Expect forecast changes.

Some of the current forecast changes and trends—

• Thursday looks to be warmer still, with highs near 87º-88º.
• Friday will have more sunshine than had been forecast earlier in the week. Clouds won’t move until evening. Highs may reach 90º
• Saturday will have a mix of clouds and some sun. Showers and thundershowers will reach the western suburbs during the late afternoon.
• Sunday will have heavy rain and thunderstorms.

---

The Haze You’re Seeing is Smoke

Posted Wednesday 08/14/24 @ 9:22 AM — The haze you’re seeing this morning is smoke from wildfires in Canada. Here’s two views of the HRRR smoke model—

Here’s another view—

Another heavier plume of smoke is forecast to arrive about 6 PM today.

In addition to warmer temperatures today, some models continue to forecast scattered showers early this evening, that dissipate as they move further southward—

---

Tuesday Weather Outlook Update

Posted Tuesday 08/13/24 @ 11:45 AM — Today, Tuesday, is another beautiful day. A few instability clouds are expected at times this afternoon. Some of the high resolution models have consistently forecast a highly isolated shower in a few spots for 5-7PM. A low confidence possibility.

Similar, even warmer days for Wednesday and Thursday. Each day has an increased possibility of isolated showers in the late afternoon.

Friday looks to be dry with an increase in cloudiness from the next system from 3-6 PM.

---

Weather Outlook Update

Posted Monday 08/12/24 @ 7:51 PM — We had a bit more instability cloudiness than originally forecast and some instability cloudiness Tuesday afternoon is also expected.

The weather still looks very nice through Thursday with mostly sunny skies and instability cloudiness in the afternoon.

The next system will be approaching during the day Friday. It looks like some cloudiness is likely by Friday afternoon. Most models keep us dry through the daytime Friday, but some of the ensembles and the ICON model suggest the showers may move in late Friday afternoon.

The weekend is looking less than stellar, with showers and thunderstorms likely.

---

Originally Posted Sun 8:01 PM —We’re currently in a cooler than seasonal pattern from an upper trough and this pattern will likely continue. Indeed, we’ll be transitioning from a trough to a much deeper trough by next weekend. Also, a tropical system will be moving far east of us next weekend as well.

Basically, we won’t be seeing any rain this week (likely changing by next weekend) and the skies will be mostly sunny with some clouds at times through at least Thursday.

Here’s the mid level atmosphere late Tuesday afternoon—

By next Saturday, a deep trough and associated low pressure will affect our weather—

The tropical system in the Atlantic should stay far east of us, unless the trough in the east greatly accentuates or tilts negative. The effects of the system may be rough surf at the shore.