Friday September 12 2025 Forecast (6:54AM)

30 Comments

DAYS 1-5 (SEPTEMBER 12-16)

High pressure from Canada delivers a cooler air mass today with more dry weather. There’s a slight change to the weekend’s forecast with a faster timing of the approaching and passing trough of low pressure, which guidance has had a lot of trouble handling it seems. Once upon a time much guidance had this feature sauntering in Sunday night and hanging around the first half of next week. Guidance consensus now has shifted to a trough that impacts our region with a shower chance later Saturday (mainly inland / west of Boston) and again Sunday, mainly from the I-90 belt southward. Consensus at this point leads me (hopefully accurately) to lean toward this scenario, which will mean I add a late-day shower threat to the forecast Saturday and shift Sunday’s shower threat focus a bit south, but still include the chance for some small hail to occur due to the cold pool of air aloft. All in all though, not a bad weekend ahead. High pressure builds back in with fair weather early next week.

TODAY: Mostly sunny. Highs 68-75. Wind N to NE up to 10 MPH.

TONIGHT: Mostly clear. Fog patches possible in low elevation locations. Lows 43-50. Wind variable under 10 MPH.

SATURDAY: Mostly sunny through early afternoon then a sun/cloud mix. Isolated to showers possible mainly west of I-95 late in the day. Highs 68-75, coolest in coastal areas. Wind variable up to 10 MPH with coastal sea breezes.

SATURDAY NIGHT: Partly cloudy. Low elevation fog patches possible. Lows 45-52. Wind SW up to 10 MPH.

SUNDAY: Sun / cloud mix. Isolated to scattered showers and a slight chance of thunderstorms in the mid to late afternoon. Highs 68-75. Wind variable 5-15 MPH.

SUNDAY NIGHT: Clearing. Lows 48-55. Wind W up to 10 MPH.

MONDAY: Mostly sunny. Highs 68-75. Wind NW up to 10 MPH with coastal area breezes.

MONDAY NIGHT: Mostly clear. Low elevation fog patches. Lows 43-50. Wind calm.

TUESDAY: Mostly sunny. Highs 71-78. Wind variable up to 10 MPH with coastal sea breezes.

DAYS 6-10 (SEPTEMBER 17-21)

Overall pattern is dry with minor systems passing by in a northwesterly air flow making for variable temperatures, which average out close to normal.

DAYS 11-15 (SEPTEMBER 22-26)

Still no indications of any significant changes to the overall weather pattern heading into late month.

30 thoughts on “Friday September 12 2025 Forecast (6:54AM)”

  4. Thanks TK !

    Nice example and explanation of how ….. timing of systems can change in the (early, medium range) and even short range time frame.

  5. Wordle: 3, I’ll take it. I was sitting on that last guess 3 for a while, having the first 4 letters in the correct spot.

    3. 5 for me. I had first four after three and went with an incorrect guess for the last letter in fourth guess. Great job giving it time, Tom

  6. While Barrow, AK has had a dusting or 2 in the last 7-10 days, this morning’s webcam shows perhaps an inch of new snow.

    This time of year, I like to see it, so long as its up there. 🙂 🙂 🙂

    1. Indeed.

      I also think perhaps 2-3 days from now, a yellow contour (30% or less) may appear off the southeast US coast.

      While very mild, the models continue to try to develop a non tropical low off the SE coast that meanders a bit, perhaps long enough to get a designation for brief subtropical or tropical development.

  9. I’m happy our area was the August exception.

    Climate reports from NOAA and the European Copernicus Climate Change Service identified August 2025 as the third-hottest August in their historical datasets, following behind the record-setting Augusts of 2023 and 2024.

  12. https://www.pivotalweather.com/model.php?m=ecmwf_aifs&p=sfcwind_mslp&rh=2025091212&fh=108&r=conus&dpdt=&mc=

    Here’s the 12z ECWMF-AIFS ……

    Again, about 5 days out now, somewhere south of us, along the east coast, something that is initially non-tropical, but possibly gains some tropical characteristics.

    It doesn’t look like much, until you look at projected QPF

    https://www.pivotalweather.com/model.php?m=ecmwf_aifs&p=qpf_048h-imp&rh=2025091212&fh=120&r=conus&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=gfs&p=qpf_048h-imp&rh=2025091212&fh=132&r=conus&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=gdps&p=qpf_120h-imp&rh=2025091212&fh=150&r=conus&dpdt=&mc=

    The last one, the GDPS actually sends little piece of it up to us.

  16. Yesterday was the 65th anniversary of Hurricane Donna’s impact on New England, and it was a significant impact at that. This storms seems to be forgotten in history for some odd reason. Perplexing. Anyway, here is an excellent Wiki article on the storm.

    https://en.wikipedia.org/wiki/Hurricane_Donna

    Highlights of Hurricane Donna…

    -The hurricane peaked at Category 4.
    -There were 5 U.S. landfalls (Florida, North Carolina, NY’s Long Island, Rhode Island, and Maine.
    -Peak wind gusts of 145 MPH on Blue Hill.
    -To date, Donna remains the only hurricane to deliver hurricane-force wind gusts to every single Atlantic coastal state.

    1. I Rember that one. We were living in Millis and to this day I have never witnessed wind that strong. We missed a week
      Of school due to so much damage,(mostly tree and limbs with wires down) even that far inland.

      1. I remember missing school too. And sitting on an enclosed back porch working on the weather system I built.

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