Thursday December 18 2025 Forecast (7:15AM)

DAYS 1-5 (DECEMBER 18-22)

High pressure nearby moves offshore today with fair and milder weather for our region. Low pressure cranks up and heads through the Great Lakes and into southeastern Canada tonight through Friday. Stronger southerly winds develop as this system moves in and its cold front will sweep through with many hours of rain showers preceding it, and a final band or cluster of heavier showers including a low chance of embedded thunder. A wind shift to west takes place and it dries out other than the chance of an additional rain / snow shower as colder air returns Friday night. Saturday, winds slacken and we can expect a sun / cloud mix as a smaller clipper low moves through the Great Lakes. This system will pass north of our region Sunday when we’ll be briefly in its warm sector between a warm front, which may produce brief insignificant precipitation Saturday night, and its cold front, which may produce a sprinkle of rain Sunday daytime and maybe a snow flurry behind it at night. The winter solstice occurs at 10:03 p.m. EST on Sunday. Fair, colder weather is expected behind that low pressure area for Monday.

TODAY: Sun much of the time then clouds arrive late. Highs 44-51. Wind variable to S up to 10 MPH.

TONIGHT: Clouds thicken. Widespread rain showers arrive west to east overnight. Lows 37-44 evening, rising through 40s overnight. Wind S increasing to 10-20 MPH with higher gusts.

FRIDAY: Overcast with widespread rain showers including the slight chance of thunder, then a clearing trend begins west to east mid to late afternoon. Highs 55-62 but starting to fall later in the day. Wind S 10-20 MPH except 20-30 MPH South Coast, gusts as high as 45-55 MPH, strongest coastal areas and higher elevations, shifting to W from west to east midday on.

FRIDAY NIGHT: Partly cloudy. A passing mix / snow shower possible. Lows 22-29. Wind W 10-20 MPH, gusts 25-35 MPH.

SATURDAY: Sun followed by clouds. Highs 35-42. Wind variable up to 10 MPH.

SATURDAY NIGHT: Variably cloudy. A brief period of very light snow possible mainly north of I-90. Lows 22-29. Wind SW 5-15 MPH,.

SUNDAY: Partly sunny. A brief rain shower possible. Highs 41-48. Wind SW 10-20 MPH.

SUNDAY NIGHT: Partly cloudy. A brief snow flurry possible. Lows 21-28. Wind NW 10-20 MPH.

MONDAY: Mostly sunny. Highs 30-37. Wind NW 10-20 MPH, diminishing.

DAYS 6-10 (DECEMBER 23-27)

Clipper low pattern and up-and-down temps, tending to be colder vs. milder. Watching for minor snow or snow shower events December 23 & 25, and a snow / mix / rain chance toward the end of the period.

DAYS 11-15 (DECEMBER 28 – JANUARY 1)

A similar pattern – a couple smaller low pressure systems with mostly minor impact, but causing variable temperatures, tending to slightly colder than normal.

43 thoughts on “Thursday December 18 2025 Forecast (7:15AM)”

  1. Thanks TK !

    Wordle: EPIC FAIL, lol !!!

    I think I had 3 or 4 letters, mostly in the wrong spot by my 3rd guess and I just never saw it or sounded out what I had.

    Obviously, when I saw the word after the fact, I shook my head.

    A Belichekian, “on to tomorrow” πŸ™‚ πŸ™‚ πŸ™‚

  2. https://www.pivotalweather.com/model.php?m=gfs&p=925wh&rh=2025121800&fh=39&r=us_ne&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=925wh&rh=2025121800&fh=42&r=us_ne&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=gdps&p=925wh&rh=2025121800&fh=42&r=us_ne&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=sfcwind_mslp&rh=2025121800&fh=36&r=us_ne&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=sfcwind_mslp&rh=2025121800&fh=42&r=us_ne&dpdt=&mc=

    The magic hr on the winds seems to be 15Z Friday morning. That works for the GFS, with 3 hr panels (1st link), but the Euro and GDPS miss it as their 6 hr panels go from 12z to 18z (2nd and 3rd links)

    The 4th link is the sfc for 12z and 18z from the euro and look at those isobars and can see the pressures dropping along the cold front. Plus, disturbance at 500 mb is strengthening as it approaches.

        1. It’s also the last time Beacon Street, where I live, was plowed. Salted multiple times but not plowed. A remarkable run.

      1. The last one (6″ snowfall or more) was the 2022 blizzard in, especially SE Mass.

        We had at least 2 ft of snow in Marshfield, in 8 hrs and we had blizzard conditions for 8 straight hours. EPIC, it was.

        Should have known it was mother natures way of saying, its going to be a while til this happens again πŸ™‚

    1. That’s a big difference with downtown Boston. My low was 31F, higher than JP and much higher than Sutton.

      Tomorrow’s high could break a record in Boston. I think 60F is possible with the southerly wind.

      I am concerned about the very strong wind – I am MUCH more anxious than my daughter who will be flying into it.

      1. Wow. That is a big difference . It was still 32 at 12:30 but when I woke up briefly at 4:00 there was a thick frost on the cars

  3. Thanks, TK.

    There’s some model mayhem regarding Europe’s long-range. As mentioned, it looks like a blocking high to the north could result in a prolonged period of cold. BUT the Dutch forecasters have not ignored the 30% chance that this does NOT happen and relatively mild or simply normal/typical conditions predominate. One meteorologist even said he thinks the 30% should be more like 40%. I like their no hype approach.

  4. Joshua – I don’t blame you for worrying about your daughter for flying tomorrow. I am the same way with my kids. Hope she has a great flight.

    TK – what do you think the peak gusts will be in the Natick area tomorrow?

    Thanks

    1. Excellent job Julie and Vicki, our co-engineers so far today.

      I got it in 5.

      An interesting thing about the solution is that it’s the only 5-letter word ending with those three letters.

      1. Nice job, both of you. At least I got it and avoid the Push Care or Kalamazoo. I’ll be sure to extend a line to Tom. πŸ™‚

  5. Maybe the one slight change I’m seeing on 12z vs 00z run is a slowing by maybe an hr or 2 of when the strongest winds could occur.

    I felt like on the 00z info, it was squarely centered at 15znand with what’s come in at 12z, perhaps it’s btwn 15z and 18z

    If that’s true, probably not a noticeable change but it helps out the south coast a bit by getting them even closer to low tide.

      1. Indeed.

        Yes, I don’t know what’s happening on pivotal weather with the RRFSA model, some of its recent runs have stopped early in the run.

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