Thursday December 31 2020 Forecast (7:37AM)

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DAYS 1-5 (DECEMBER 31 – JANUARY 4)

On this final day of 2020, we won’t see much sun, but after morning rainfall exits the South Coast region, it will be a dry day. High pressure building across eastern Canada and pushing down into New England will bring some clearing tonight and 2021’s first day will dawn with sunshine, but clouds will advance steadily as the day goes on and another low pressure area approaches from the southwest. This system will have colder air to work with so snow & sleet are likely to be at the leading edge of the precipitation shield of this low pressure area when it arrives on Friday evening, but warmer air aloft will change that to rain during the night and into Saturday morning. However some colder air trapped at the surface may result in some pocket of freezing rain mainly over interior valley locations before temperatures rise sufficiently to eliminate that issue. By Saturday afternoon, low pressure will have crossed the region and drier air will be moving in behind it. But this dry interlude will also be short-lived, as a follow-up low will pass by the region Sunday night into Monday with another period of precipitation, the details of which still need to be worked out.

TODAY: Mostly cloudy. Rain South Coast region this morning. Highs 42-49 this morning, then slowly falling temperatures during the afternoon hours. Wind W 5-15 MPH with higher gusts.

TONIGHT (NEW YEAR’S EVE): Clearing. Lows 18-25. Wind N 5-15 MPH evening, diminishing overnight.

FRIDAY: Sunshine fading behind increasing high cloudiness. Highs 32-39. Wind N up to 10 MPH.

FRIDAY NIGHT: Thickening overcast with snow/sleet northwestern areas and mix/rain southeastern areas arriving from southwest to northeast, changing to rain except possible freezing rain interior valley locations. Lows 30-37. Wind N to NE up to 10 MPH inland and 10-20 MPH coast.

SATURDAY: Cloudy with areas of fog and a chance of rain in the morning. Breaking clouds in the afternoon. Highs 45-52. Wind NE to variable 5-15 MPH becoming W.

SATURDAY NIGHT: Clearing. Lows 25-32. Watch for black ice formation. Wind W up to 10 MPH.

SUNDAY: Increasing clouds. Chance of rain/mix/snow by late in the day. Highs 36-43. Wind N up to 10 MPH.

SUNDAY NIGHT & MONDAY: Cloudy with rain/mix/snow possible. Temperatures 35-45. Wind NE to variable 10-20 MPH shifting to N.

DAYS 6-10 (JANUARY 5-9)

High pressure builds in with fair weather January 5. Weak system may bring a few rain/snow showers, milder on January 6. High pressure builds back in with fair weather January 7. Next threat of unsettled weather comes from passing low pressure about January 8 before dry/cold weather ends the period.

DAYS 11-15 (JANUARY 10-14)

Stronger indications of a blocking pattern setting up during this period. Will have to watch one or two low pressure areas, strongest chance for unsettled weather around January 12-13.

60 thoughts on “Thursday December 31 2020 Forecast (7:37AM)”

  2. Thanks TK!

    If New Year’s Eve the wind blows south
    It betokens warmth and growth.

    If west, much milk and fish in the sea.

    If north, cold and storms there will be.

    If east, the trees will bear much fruit.

    If northeast, then flee it, man and brute.

    -New Year’s Weather Folklore

  4. All of the arctic air is over all of Siberia. The Euro’s projection of it looks impressive for that side of the northern hemisphere. Simply none on this side though.

  9. 12z GFS really intensifies the Sunday night system and as such, provides a decent wrap around hit of snow, perhaps a projected comma head ???

  10. back to depending on dynamics again, struggling to have cold enough air in the column. In early January ……….

  12. I think we have a reasonable chance at a moderate snow event
    Sunday night into Monday. Precip type near the coast may
    be an issue at times, especially early on in the event.

    Anxious to see today’s 12Z versions of the UKMET but most
    especially the EURO.

    You will note that the GFS has joined the UKMET in keeping
    this system hanging around for a while. 🙂

    1. It definitely slowly intensifies the 500 mb feature as it is passing through. If this projection is correct, then I am in agreement that there´s opportunity for something up to a moderate event.

  14. If snow materializes in the next 2 weeks, it will be accomplished within an overall warmer than average pattern. Canada will have crazy temperature anomolies (above average).

    Following any snowfalls, daytime temps will be above freezing on the non-stormy days, so retaining snow cover long term may be a challenge.

  16. The Sunday night into Monday 12z CMC takes right over southeastern MA. Needs to track more to the south and east to bring that snow area western MA down to get more of us into the snow.

        1. All we need is a bit of a shift to the south and east to bring that accumulating snow into more of SNE. There is plenty of time where that is in the realm of possibility.

  20. TK I look forward to your 2021 weather predictions tomorrow. It always a good read as you look into your crystal ball on what your think will happen weatherwise in 2021.
    Looking back at my predictions for the year I got two things right.
    New England once again goes another year without a direct hit from a Hurricane
    Middle of December will have the first widespread snowfall for SNE but unfortunately the snow will be gone and we won’t have a White Christmas

  23. So as you see, and no surprise, our guidance will continue to struggle with solutions. Just have to take everything fairly lightly until we get into short range zone, then fine-tune.

    No changes to overall thinking. Same for the Friday night / Saturday morning system.

    The Sunday night & Monday system does not impress me. However, if it’s slower to exit it may play a role in the set-up for something one week from tomorrow. Stay tuned…

    In case any of you depart the comments section early, or I don’t get a chance to return to it myself before today runs out of time, then I wish you all a safe, happy, & healthy New Year! I know we are coming out of this year in a position we didn’t imagine ourselves being in just one year ago, but reality is, we are. It can only help us to try to be as optimistic as possible in our own way, and to those around us. We’ll get there……….

    Peace to all!

      1. Some, but I may take a short ride this evening to visit a few more. It will take the place of the fireworks display I usually go to (8 p.m.) at Hampton Beach, which, of course, is cancelled this year.

    1. Although that run gives a 1/4 to 1/2 inch ice storm to the Worcester Hills and 1 to 3 inches of snow from just northwest of Boston through the Merrimack Valley.

  25. According to Pete, a “plowable” snow for Sunday night/Monday. At least 2” to as much as 6” as it may hang around awhile into much of Monday.

            2. The NAM doesn’t go out far enough to see the end of Monday’s event, and it’s probably under-estimating the cold air before that point as well. Not only is the NAM unreliable beyond 60 hours, but after its run time we may see a dramatic temperature drop in all levels of the atmosphere as that low deepens offshore. It’s obviously too soon to get detailed, but that system has some decent potential to deliver a snowfall to the city that will require removal of some kind.

              2. Didn’t you just say above Sunday/ Monday not looking impressive. It doesn’t matter to me what it does . Have a safe night

                2. It does change old salty but I’m going all rain Boston / south coastal areas . Happy New year old salty .

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