Daily Archives: Wednesday, May 15, 2024 10:06 am

Philadelphia Weather Outlook

THIS WEEK’S WEATHER

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Things have stabilized somewhat with my family medical situation, and I hope to be posting some thoughts and commentary about the current weather over the coming days. For the time being, postings won’t be as frequent or comprehensive as they have been in the recent past.

Posted Thursday 05/16/24 @ 4:03 PM — Just a quick update to yesterday’s note about the upcoming weekend weather. Many of the models, particularly the ECMWF and to some extent, the GFS, have moved towards a more southern track of the next low pressure system moving east near our area this weekend. As a result, they have little in the way of rain for us on Saturday and even less for Sunday.

Looking at the NAEFS (which combines the Canadian and NOAA’s GEFS), a measurable amount of rain is still forecast here for both Saturday and Sunday.

So there’s uncertainty with the weekend forecast at this time. I’m leaning towards the NAEFS with some light rain, but I’ll be the first to tell you I could be wrong here.

NAEFS forecast for Sunday at 2 PM. While the system is forecast to be further south than previous model runs, it still brings some rain to our area both Saturday and Sunday. (Click on image for a larger view.)

Previously Posted Wed 10:06 AM —

It’s been over a month since I last posted here. After weeks away bicycling and traveling in southern Spain, I’ve returned to a what appears to be an highly unusual weather pattern.

A few features of this pattern have caught my attention:
• Extremely hot wet weather in the southern US for early May
• Very dry and cooler far north of the US into Canada
• A persistent storm track that takes low pressure systems across our region with low pressure systems persisting repeatedly along the coast.
• Recurrent northeasterly surface winds resulting in cool temperatures for us.

Patterns that are a concern for our region:
• The extreme heat in the southern US will eventually push towards us.
• Forest Fires in central and western Canada have smoke trajectories that will enter the US, as they did last summer.
• I’m not sure but I think the excessive rainy pattern we’ve had will be replaced by very dry conditions here over the summer.

In the short term, the coming weekend looks to be wet. Here’s the latest NAEFS forecast for Sunday—

The latest NAEFS forecast for Sunday shows another rainy weekend. I’ve annotated the map with some of the features and patterns I mentioned above. Of interest is the orange 760 thickness line (500-1000mb thickness) that pokes into Texas and southern Florida. This is very hot for mid May. (Click on image for a larger view.)

Regarding the smoke from fires in Canada, the latest HRRR smoke model shows some beginning to spill towards us—

HRRR smoke forecast is showing some building smoke to our northwest. (Click on image for a larger view.)

More weather to follow…