Monday December 21 2020 Forecast (8:32AM)

43 Comments

DAYS 1-5 (DECEMBER 21-25)

Welcome to winter! Last year’s solstice sunrise was brilliant, whereas this one was obscured by low clouds and fog. in many areas the temperatures have been below freezing and some of that fog has contributed to icing on untreated surfaces so use caution if you are outside this morning. Some drying between an offshore storm system and an approaching trough from the west should result in partial clearing at times today and early this evening. This leaves us still with a chance to see the conjunction of Saturn and Jupiter low in the southwest sky between 5:00 p.m. and 7:00 p.m. The system coming from the west may produce some snow showers on Tuesday and behind it comes a reinforcing shot of cold air as high pressure moves in on Wednesday. I believe we are still seeing model corrections on going for the situation on Christmas Eve and Christmas Day. High pressure offshore will allow milder air to flow into the region on Christmas Eve. An approaching front from the west will bring rain showers to the region that night and into the early hours of Christmas Day before a rapid temperature drop which may end the rain as snow in some sections. Still have some fine tuning to do on this forecast for future updates.

TODAY: Clouds and areas of fog to start. Early rain Cape Cod. Clouds break for sun at times. Highs 35-42. Wind variable up to 10 MPH.

TONIGHT: Clouds return west to east. Lows 23-30. Wind variable 5-15 MPH.

TUESDAY: Mostly cloudy. Snow showers likely, except rain or snow showers South Coast. Highs 34-41. Wind NW 5-15 MPH, higher gusts.

TUESDAY NIGHT: Clearing. Lows 15-22. Wind NW 5-15 MPH.

WEDNESDAY: Mostly sunny. Highs 31-38. Wind W 5-15 MPH.

WEDNESDAY NIGHT: Mostly clear. Lows 18-25. Wind SW up to 10 MPH.

THURSDAY: Partly sunny. Highs 38-45. Wind S 5-15 MPH.

THURSDAY NIGHT (CHRISTMAS EVE): Cloudy. Rain showers likely. Temperatures rise to 48-55. Wind S 10-20 MPH, higher gusts.

FRIDAY (CHRISTMAS DAY): Cloudy start with rain showers possibly ending as snow showers, then a sun/cloud mix with a possible snow shower. Temperatures fall to the 20s. Wind W 15-25 MPH, higher gusts.

DAYS 6-10 (DECEMBER 26-30)

Fair, chilly weather expected for December 26-28 and then a risk of a wintry weather threat to end the period.

DAYS 11-15 (DECEMBER 31 – JANUARY 4)

Tranquil weather for the last day of 2020 before a quick-moving system brings some unsettled weather to greet 2021, followed by a shot of colder, dry weather.

43 thoughts on “Monday December 21 2020 Forecast (8:32AM)”

  2. Thanks, TK…

    A Happy Winter Solstice to all!

    I just noticed that Google has wonderful Google Doodle celebrating tonight’s Great Conjunction…not to be confused with the Great Conjugation which is what I am doing with my Spanish students this morning. 🙂

  4. Good morning and thank you, TK.

    Fingers crossed for tonight. Thank you for both time and direction.

    We finally settled on Christmas. My oldest and family will have self quarantined for two weeks so we can see them. Highly exposed daily we will have to zoom with my son but he seems ok with that with helps me feel ok. I’m still hoping for weather that lets people gather outside even though that is moot for us now. First, because family is vitally important, especially this year. Second, because it may force people who just don’t do what is best to go inside.

    1. According to a Ch. 7 met, most will lose 100% by the end of Christmas Day. 🙁

      Hope TK’s outlook verifies instead.

  9. Re : snowcover

    The good news is we’ll get to the morning of Dec 24 with a lot of snow on the ground

    If a second low, later on Christmas Eve Day develops in the vicinity of NY state and is intensifying, that could be close enough and strong enough with its associated pressure gradient to bust inversions in most areas, save for maybe the CT river valley and perhaps the Merrimack valley.

    We see many examples of how cold air can build in southern Canada and how impressively cold it can be.

    Well, a couple hundred miles to our south-southeast is the Gulf Stream. In it and south of it, the whole ocean is 70F + and unfortunately, it can deliver an impressive 60F temp and dewpoint airmass to most areas of southern New England for several hours if the push is strong enough.

    I hope TK is correct too !! We’ll see 🙂 🙂

  10. Non weather.

    Barr is speaking now finalizing the investigation into the pan am Lockerbie bombing 1988. As you may recall, Macs sister, Jenny, flew over on flight 103 but by the grace of God did not fly back on it. It was two days before we knew she was not on the plane

      1. Mac’s mom had just had her second quintuple bypass. We were very worried about her. I kept calling pan am understanding how horribly busy they were. We got a voice message at 4 am two days later and damned if we could understand whether the man said Jen was or was not on the flight. Jen was an amazingly kind soul. I suspect you also remember she volunteered to fly into Iran to get the hostages and often flew into Vietnam for wounded

        Thank God that finally, after 32 years, the families have some form of closure. I just cannot imagine how difficult it has been for them

        1. Thanks Vicki. I don’t recall your story as I may have simply missed it along the way. I actually thought the PanAm bombing was already finalized a number of years ago.

          Thanks for remembering.

  11. I am somewhat surprised that very little if any window since last week’s storm departed. Unusually quiet in the wind department. Not even a good breeze.

  13. We better hope the 18z NAM is wrong (and I think it is). That’s gotta be one of the strongest, maybe the strongest, LLJ I’ve ever seen depicted on a model at the end of its run. Nearly 100 kt at 925 mb off the NJ coast at the end of its run, and those values would likely increase by the time it’s over SNE. Along with a beefy squall line to mix most of that down.

    Just for fun, if you extrapolated that run out I would wager on wind gusts of 90-100+ mph at an elevated site like Blue Hill, and 60-85 mph for most other places. But again, I think that is wrong/overdone…

  14. The 18z NAM has been drinking the egg nog. I agree way overdone. Even if we don’t see those kinds of winds going to be turbulence for Santa.

  16. Again, I’m surprised at the loss of snow in my area as it hasn’t been that much above freezing past couple days. I’m down to 6” from 15”in the most exposed portion of my yard

    1. Eric Fisher
      @ericfisher
      54m

      There should be plenty of storms. Snow is always a product of exact track but opportunities will certainly be there

    1. More promising news as we had into January with the Euro now joining the GFS and projecting a significant PV weakening. IF these models are correct, we could be seeing a continued overall favorable pattern for winter weather right through mid January.

      1. Actually, Judah often mentions that the maximum effects of a PV disruption are typically realized a few weeks after the event happens. If indeed January 7 were the date, we would more realistically see the impact the second half of January.

    1. It already isn’t. I think we are going to see a lot of winter snowfall forecasts bust again this year (in the opposite way from last year). And I am not referring to TK’s. I’m liking the above normal snow forecast, but thinking we will end up with more snow chances in Jan/Feb and get there sooner than March.

  23. 14 more inches and Eric Fisher’s forecast will bust. Janice Huff of WNBC in NYC said this winter is going to be just like last winter. NYC has 10.5 inches compared to 4.8 inches all of last winter so that forecast already busted.

  24. 00z models looking worse and worse for the Christmas storm. Further west track with the parent low pressure, less progressive, and longer period of heavy rain and wind. They are popping a second wave of low pressure along the front which enhances and prolongs the precip. This sucks!

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