Sunday Forecast

75 Comments

8:33AM

DAYS 1-5 (DECEMBER 15-19)
And now the wind. No big changes on this discussion so just basically reiterating what I said yesterday and adding a few details. Big low exits via eastern Canada today and we get dry weather but some cloudiness, especially this morning, and lots of wind, although it won’t be particularly cold as there was no arctic air ready to whip in on the heals of yesterday’s rain. We will see colder air settle in more significantly tonight and Monday, however as high pressure positions itself north of the region. And the along comes the next low pressure area, certainly far weaker than its predecessor, and coming more from the west southwest via the Ohio Valley. This one has more cold air to work with so instead of straight rain we’re looking at an event that announces itself with increasing cloudiness Monday but precipitation staying to the south initially, then finally pushing a little more to the north and getting into the region in the form of snow early Tuesday. But enough warm air will be involved aloft and barely enough at the surface for a flip to rain along the South Coast and a mix at least into the I-95 corridor, but anywhere northwest of there will likely stay mainly snow from this event. Snow amounts in the detailed forecast below will reflect this expected scenario. Behind this system a potent upper level disturbance and accompanying cold front will set off snow showers and possible heavier snow squalls Wednesday, but location and timing if obviously impossible to pin down just yet. That will turn into a now-casting event on Wednesday. The theme of cold Thursdays will continue with yet another one thanks to modified arctic high pressure at that time.
The forecast details…
TODAY: Clouds and interals of sun morning. Sun and passing clouds afternoon. Highs 42-49. Wind W 15-25 MPH, gusting 35-50 MPH.
TONIGHT: Clear. Lows 22-29. Wind W 10-20 MPH with higher gusts, diminishing overnight.
MONDAY: Sunshine followed by increasing high clouds. Highs 30-37. Wind variable up to 10 MPH.
MONDAY NIGHT: Cloudy. A touch of light rain/snow possible South Coast Lows 25-32. Wind light variable.
TUESDAY: Overcast. Snow to rain South Coast, snow to mix I-95 corridor which may include sleet and/or freezing rain, snow NW of I-95 area. Snow accumulation a coating to 1 inch South Coast including Cape Cod, 1-3 inches most of southeastern MA and RI to near Boston, 3-5 inches from I-95 area northwestward. Highs 30-37. Wind E to NE 5-15 MPH.
TUESDAY NIGHT: Mostly cloudy with lingering snow showers evening. Clearing overnight. Lows 22-30. Wind N 5-15 MPH.
WEDNESDAY: Variably cloudy. Afternoon snow showers/squalls possible. Highs 33-40. Wind W 10-20 MPH shifting to NW late.
WEDNESDAY NIGHT: Variably cloudy with evening snow showers possible. Clear overnight. Lows 12-19. Wind NW 15-25 MPH, higher gusts. Wind chill 0-10 at times.
THURSDAY: Mostly sunny. Highs 23-30. Wind NW 10-20 MPH. Wind chill below 20.

DAYS 6-10 (DECEMBER 20-24)
The polar jet stream will deliver cold weather for this period, and we’ll have to keep an eye on a piece of energy to the south that develops a storm off the East Coast, possibly close enough to deliver some snow/mix sometime between late December 21 and early December 23. A disturbance may bring a risk of snow showers December 24.

DAYS 11-15 (DECEMBER 25-29)
A little more activity in the subtropical jet stream later in the month but for now leaning toward most of that energy staying to the south or reaching this area in weakened form (possible system around mid period) as the polar jet tries to hang on but weakens slightly. Much of the period will see fair weather.

75 thoughts on “Sunday Forecast”

  2. To Joshua and Scott….So very sorry to hear of the loss and difficulties that you are both currently going through.

    1. At the moment I’m comfortable with 1-3 inches for you and then a period of sleet/ice/rain then ending as flurries.

  5. Thanks, TK…
    The sun sets exactly one minute later today than it did last Sunday.

    Light always conquers the darkness.
    I hope that brings some consolation to all those who are troubled today.

    2. I think that may be a little over amped.

      I like a system a little further south and something happening between high pressure to the north and low pressure to the south. Long way to go though.

      Also think GFS is a tad too warm for Tuesday.

      1. When you say “something happening between high pressure to the north and low pressure to the south”

        Do mean an ocean effect event? Or some other mechanism to produce precip with the center a long ways away?

        The other day the GFS showed something just like that.

  8. Thanks TK.

    I was just about to post the Euro Dave…Wow on that overnight run. Blizzard for a portion of SNE with major accumulations.

    Ryan Hanrahan tweet on that….

    @ryanhanrahan
    2h

    The Euro has a blizzard for next weekend. Don’t get too excited yet as it is an outlier solution… only 15% of the Euro Ensemble members drop over 1″ of snow on Connecticut next Sunday. Something to watch but that’s about it for now. #nbcct

    https://twitter.com/ryanhanrahan/status/1206216849534410752?s=20

  9. I must say that the various models are ready the tea leaves differently for the 22nd.
    Wow!!

    Euro has a bomb.
    GFS has a suppressed bomb well to the south with not a drop of precip here.
    CMC hasn’t a clue and only shows a little clipper dropping down.

    Interesting.

    Can’t wait to have a peek at the 12Z Euro.

    1. Euro has no other model support for that solution. The GFS and ICON solutions have the storm suppressed so far south that it is a miss even for most of North Carolina!

  11. TK – Shouldn’t Vicki be squarely in the 3-5 inch range? And based on your amounts I get the impression that Boston is on the fence between 1-3/3-5 inch, correct?

    Are both Tuesday commutes affected the same or one not quite as much?

    1. I have her in 1-3 for now because of where I think the warm air aloft ends up. I envision a flip to sleet sooner in that area.

      1. I can now see why. Vicki is much further south into Worcester County that I envisioned. In fact, geographically Sutton is further “south” than Boston.

        1. And I am in south Sutton which makes me at risk for falling into either RI or CT. 😉 😉

          I choose CT with no offense intended for RI

        2. But it’s also surrounded by much different topography than Boston. South vs North is only part of the story.

  12. Crappy 12z GFS operational run there. Would have to depend on whatever falls Tuesday/Wed to last till next week for a White Xmas. The 23rd storm is a whiff and Christmas day is dry with highs in the low to mid 40’s. A cutter with rain showers follows for the 27th. Fortunately still a ways off…

        1. It’s a cutter but it’s a break-away system that kind of escapes the subtropical jet and finds its way via a weakness to whatever form the polar jet stream is in. I made the term up myself, actually. They tend to bring brief warm-ups but not a lot of rainfall, then become embedded in the polar jet as a newly developed system somewhere from eastern North America to the North Atlantic, depending on the pattern.

  15. The “December 17 is the snowiest day of December in SE New England” theory is going to be strengthened in 2 days. 😛

    1. Did you ever check the numbers? I recall you said in 20 years when you initially said this. I went back till start of whw (9 years) just comparing 17 and 9…guess why 9. They are pretty even with 9 inching over 17 but….well, inches 🙂

      2010 meh
      2011 17 snow showers
      2013 both snow showers
      2014 9 mix rain snow
      2015 meh
      2016 17 range 7 CT to 4 JP;
      2017 9 range 7 CT to 6.5 JP

  16. Well my B’s won one last night after a 5 game skid and now I want the P’s to do the same. They don’t look great right at the moment, but things should get better … I hope!

    To me the players look colder than what temp actually reads.

        1. you got it! Impressive snow in the south. the animation of this storm looks cool so i posted it. We will probably never see any storm to this magnitude anytime soon.

    2. Not happening. A day or 2 of 40+ perhaps. Overall, not that warm.

      That was based off a GFS run that’s “over-ridging” the Northeast.

        1. Because it is way in the future and he needs to put something out per network bosses. You know this far out that it is no more than a potential.

  20. Wind is crazy and chilly. I had to take down my manger. First time in the four years we have been here. It’s held in with long steel rods but the ground has absolutely no frozen layers so nothing to hold them in

    We’ve had minimal frost layers and massive winds in the past four years …enough so the rods bent at ground level…but this is first year of no frost layer.

  22. The Power was not out for my Dallas Cowboys today. Where was this all season. Finally beat a team with a winning record and play like this next week against the Eagles there going to the playoffs.

  23. Vicki I haven’t gone back all that far to check 17th vs 9th. I’ll have to do that sometime. 🙂

    Kane that loop is an easy one for me. Still the most impressive synoptic scale cyclone I have seen impact the US (and Caribbean & Canada).

    1. All very similar and I’m in agreement with them. The icing is a bit concerning for travel more than any damage. There won’t really be enough accretion to take down trees & wires.

  26. Not a fan of Ryan Maue on Twitter but though folks would like to know this :

    Over the past 30-90 days, ECMWF model skill has been particularly excellent 0.93 – 0.94

    The Euro remains king heading into the 2020s.

    1. While true in the 90 day period, it has struggled significantly at times the last half of that. Luckily for it some of the other medium range models struggled just a bit more. 😉

  27. Operational GFS has made a slight correction toward a colder Christmas week, not the mild one we heard about earlier. Ensembles support a northwest flow and Canadian chill while the milder air is held at bay.

  28. Just took quick peek around. Some maps later, but for now just wanted to say that
    the RPDS and the HRDPS are quite bullish on snow for tomorrow with a 6 inch swath
    Boston Westward. All other models appear to be in line with forecast of a general
    2-5 inches. It all depends upon how far North the warmer air aloft makes it.
    So, we shall see. Waiting on all of the 12Z runs.

    fwiw, here is my F5 Weather Service snow map for the Euro.

    https://imgur.com/a/HiKWqc4

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