Category Archives: Philadelphia Weather Outlook

THIS WEEK’S WEATHER

#weather #paweather #wx #pawx #philadelphia #phillywx

Update Wed 05/17 @ 9:39 PM — The dry weather and somewhat cooler than average temperatures will continue through Friday.

Some showers are looking increasingly likely for Saturday, especially Saturday afternoon. There’s a wide range of forecasts regarding precipitation amounts.

It doesn’t look like we’ll get much rain and the spread in the models varies from 0.2″ to as much as 0.8″. I think we’ll see the lower end.

The current NAEFS, which is a blend of the GFS and Canadian Global, captures the scenario, with the heavier rain shearing off to our north and west and another area of heavier rain well to our east—

Today’s 18z NAEFS forecast for Saturday late afternoon. The heavier rain looks like it will miss us. (Click on image for a larger view.)

Update Tue 05/16 @ 8:16 PM — The dry weather continues…until Saturday. It doesn’t appear that we’ll get much rain on Saturday, possibly a few tens of an inch. Then more dry weather. Delightful, but the trees, flowers and grass are probably getting thirsty by now.


Update Mon 5/15 10:59 PM — Tuesday looks warm with high temperatures approaching 80°. Sunshine through high cirrus clouds. It looks like the showers Tuesday night will pass us by, even further to our south. Our dry weather continues.


Previously Posted Sun 9:14 PM —

An uneventful weather week is in store for us. Nice weather is expected Monday and most of Tuesday before a cold front moves through Tuesday evening.

This afternoon’s 18z NAEFS forecast for Wednesday. The red line (540 thickness line) captures the general position of the air masses. with a cold dip in the jet stream to affect our weather Wednesday through Friday.

It’s been about two weeks since we’ve had any substantial rainfall, especially from the city northward.

We’re in a very dry weather pattern right now, with any precipitation moving just to our south. This was the case this past Saturday and it will likely be the case this coming Tuesday evening. It was also the case last summer when the word ‘drought’ came back into the local lexicon. Hopefully, this dry pattern will be a temporary situation.

For late Tuesday, the Philadelphia area will again be the dividing line between some rain (0.15+”) to the south and almost zero rain in the northern suburbs. Heavier rain is forecast for southern parts of South Jersey and Delaware.



THIS WEEK’S WEATHER

#weather #paweather #wx #pawx #philadelphia #phillywx

Friday Update

Update Fri 5/12 1:01 PM — A quick mobile update. The latest NBM is insistent on showers in the PHL area on Saturday. Several models keep them to our south, only affecting southern Chester and Delaware counties. Update this evening.


Forecast Update

Update Thu 5/11 9:57 PM — Hazy sunshine through a high thin cirrus cloud layer on Friday. High 85°-87°.

NBM forecast high temps for Friday (Click on image for a larger view.)

There’s still uncertainty with the northern extent of the light rain on Saturday. Philadelphia remains on the northern edge of the rain shield. Typical rain totals range from zero to 0.3 inches, depending on the model. The Canadian models and the latest HRRR consistently keep us dry. Tonight’s Model Blend (NBM) has 0.2-0.3 inches.

I’m leaning towards the drier forecast at this time.

Tonight’s 00z HRRR shows light rain to our south, no rain for the immediate PHL area. (Click on image for a larger view.)

Thursday Forecast Update

Update Wed 5/10 10:47 PM — After today’s blue skies, Thursday will have sunshine through high cirrus clouds for much of the day, as moisture aloft moves over the upper ridge.

I’ve been keeping my eye on Saturday. The longer range global models have rain showers Saturday morning into early afternoon. The few higher resolution models whose forecasts extend that far (NAM, RGEM) keep the showers to our south, even further south than the RGEM graphic posted immediately below. I’m leaning towards the drier forecast for Saturday at this time, but with much above average uncertainty.


Wednesday Forecast

Update Wed 05/10 @ 8:22 AM — No change in the forecast for Wednesday (today) through much of Friday. Friday will have hazy sunshine through increasing high clouds (cirrus); mid-level clouds move in late afternoon Friday.

In keeping with our new pattern of dry weather, most of the showers on Saturday will be to our south, in Delaware and South Jersey. Areas from north of the city and northward may be just cloudy.

CMC-RGEM shows most of the rain to our south on Saturday (Click on image for a larger view.)

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Our weather this coming week will be controlled by an upper air ridge with a disturbance moving over the top of the ridge towards us on Tuesday—

Today’s 12z NAEFS forecast for Tuesday shows the upper ridge in the middle of the country with a disturbance moving across the ridge and giving us some showers/rain on Tuesday. (Click on image for a larger view.)

This Tuesday system doesn’t look like a big rain maker. In fact, after the major rains (3-5″) of 8 days ago, it appears that we may even be entering into a much drier pattern for awhile.

Following Tuesday’s showers, high pressure builds in and fairly nice and tranquil weather is expected into at least Saturday.