Wednesday December 18 2024 Forecast (7:24AM)

80 Comments

DAYS 1-5 (DECEMBER 18-22)

A weak, fast-moving low pressure area will deliver its slug of precipitation to our area tonight and early Thursday while it’s mild enough for rain, however it can both start and end mixed with wet snow well northwest and north of Boston, with no additional impact. It starts to turn colder Thursday after the low exits, and the coldest air of the season so far moves in during Friday lasting through the weekend. This can be accompanied by some ocean-effect snow showers as a northeasterly air flow will set up between Canadian high pressure and offshore low pressure to our southeast. Potentially, some of the precipitation shield from the low can make it far enough north for a steadier period of snow (rain to snow Cape Cod) in southeastern MA late Friday. A more northerly air flow will confine ocean effect snow showers to Cape Cod Saturday, and dry weather will dominate the region on Sunday. The winter solstice occurs at 4:20 a.m. Saturday.

TODAY: Increasing clouds. Highs 41-48. Wind variable up to 10 MPH.

TONIGHT: Cloudy. Rain arrives early, possibly mixed with wet snow briefly well north and northwest of Boston. Lows 35-42. Wind N to NE up to 10 MPH.

THURSDAY: Cloudy start with rain ending, possibly mixed with snow, especially north and west of Boston. Clouds decrease thereafter. Highs 38-45. Wind NE to N 5-15 MPH.

THURSDAY NIGHT: Mostly clear. Lows 21-28. Wind N 5-15 MPH.

FRIDAY: Variably cloudy – most sun north and west / least sun southeast. Snow showers possible to probable Cape Ann to MA South Shore, especially afternoon. Steadier rain/snow possible Cape Cod and a chance of steadier snow into southeastern MA late-day. Highs 30-37. Wind NE 10-20 MPH, higher gusts especially coastal areas.

FRIDAY NIGHT: Cloudy. Snow or snow showers most likely southeastern MA. Lows 20-27. Wind NE 10-20 MPH, higher gusts in coastal areas.

SATURDAY: Partly sunny. Additional snow showers possible favoring eastern coastal areas especially southeastern MA early then just Cape Cod by midday on. Highs 25-32. Wind NE to N 10-20 MPH.

SATURDAY NIGHT: Partly cloudy. Lows 11-18. Wind N 5-15 MPH.

SUNDAY: Partly sunny. Highs Highs 22-29. Wind NW 5-15 MPH.

DAYS 6-10 (DECEMBER 23-27)

A weak low pressure area from the west can bring some light snow or snow showers (rain or snow showers South Coast) at mid period, otherwise a fairly benign pattern is expected around the holiday with temperatures starting below normal then moderating to above normal.

DAYS 11-15 (DECEMBER 28 – JANUARY 1)

Pacific-dominated air flow brings milder weather but minor precipitation threats as we wrap up 2024 and welcome 2025.

80 thoughts on “Wednesday December 18 2024 Forecast (7:24AM)”

  2. Good morning and thank you TK.
    models still back and forth regarding Friday into Saturday. I guess we’ll find out.

    1. #MeteorologyNotModelology

      Always liked Bernie and his analysis. His old Accuweather.com bloopers are hilarious.

    2. Just Bernie’s usual “wishcasting” I’m afraid. That scenario rarely happens if ever. Another Christmas will go by without a White Christmas. ❄️ 🙁

      1. Well, we don’t know that just yet, do we? 🙂
        Perhaps, then again, one never knows.
        Watching the 12Z runs for changes. Hard to say so far.

  8. I am looking at the 12z NAM if that area just west of me could shift a little to the east I could get in on some snow. So close yet so far.

  11. I keep looking at the 850 mb and 925 mb winds and for a few hrs, there is some modest NE flow off of the ocean.

    I think, at this point, its reasonable most of the synoptic, deep lift, rain and snow misses SE of us.

    But, there is a 3-6, maybe 9 hr window, where somewhere northwest of the synoptic snow, there should be some light moisture moving in off the ocean somewhere in eastern MA, but the models are REALLY struggling with this more micro part of the event.

  12. Thanks TK.

    No comments from anyone on the Christmas DAY snow that the GFS has been showing??

    This was from the 6z GFS:

    https://www.pivotalweather.com/model.php?m=gfs&p=prateptype_cat-imp&rh=2024121806&fh=180&r=us_ne&dpdt=&mc=

    Kuchera Snow:

    https://www.pivotalweather.com/model.php?m=gfs&p=snku_024h-imp&rh=2024121806&fh=186&r=us_ne&dpdt=&mc=

    Might have a better chance for widespread accumulating snow from that one vs. this next system, although the other models werent as robust. We’ll see if it is still there on 12z.

    3. Been watching that. Totally been ignoring the short term. The Christmas Day possible mood snow has been on the runs for a bit.

  20. Thanks TK

    Mood snow is great on Christmas Eve or day. But those may be the only two days of the year that I would not wish for a storm.

  21. CPC too warm again on the 6-10 & 8-14. I figured it out. They are focusing solely on 500mb heights for the base forecast. You cannot do that. There are too many regional quirks that will undermine the generalities.

    1. Regional quirks and microclimates within a forecast area are the downfall of smart, but inexperienced or unfamiliar forecasters. As so many young mets come into local media, or NWS offices its never been more apparent.

    1. Hi SSK. I would say that lines up with TK’s forecast of passing snow showers. Thankfully nothing big since a lot of folks have last minute shopping, like me. 🙂

  29. The Friday and Christmas Day events will have temperature boundary issues (30s) along the coastline. Boston may very well yet go another Christmas bare with a cold rain along with a lump of coal. ❄️ 🙁

    Last White Christmas = 2009 (15 years)!!! ❄️

    I also have a bad feeling that we are being set up for 3 straight SNOWLESS winters, especially Boston. Our very dry fall likely already sealed winter’s fate long before fall was even half over.

    We will see.

    1. I have Boston down for a very low amount of snow this season, we shall see. Pretty much uneventful weekend coming up , except it will be colder .

  30. Jeez, come to check out the weather and all I read is how bad winter is going to be. So glad folks can say winter is over already on December 19th. How many times have we seen this, I also believe that December generally warmer and less snow than it used to be. March seems like the new December.

    2. +AMO
      Milder autumns, colder springs (in general)

      This December will be an exception, as it will end up colder than average at the end.

          1. I will never understand that reasoning. To use the past several decades which have been the hottest of all time skews the normal.

  36. .97 here in my part of JP for this event. Definitely more than I anticipated. Good drink for sure.

    NWS is keeping a close on tomorrow night into Saturday and boy does it look really cold for a few days. Single digits overnight Saturday.

    Can I ask a favor of folks, for those who hate winter or love winter can we just not constantly say it’s not going to snow etc… some of us get excited and there is no reason to always be telling people it’s not going to and vice versa. Thanks and much appreciated.

  37. From Bernie on X

    its the 6z nam & one run so I am not even going to post it. However, it does show my concern about more backside precip from the coastal storm Fri night from NYC to eastern Maine (accum snow). Not a NAM fan, but one of its strengths is East Coast cyclogenesis. More on this later

  38. Also from Bernie Rayno
    Very tricky call. I have seen this set-up many times in my 35 year career and have seen it go both ways (and have busted on it as well)

  39. Tricky forecast. I’d say we’ll see “some” snow. How much is the bigger question. Models range from an inch or so up to 6 inches or more. First one up will be the 12Z HRRR, WAITING……..

  40. I am rooting for the NAM as that gets me into the action. Eastern areas of SNE is looking good for some accumulating snow at the moment.

Comments are closed.