Friday Forecast

93 Comments

9:23AM

Merry Christmas!

DAYS 1-5 (DECEMBER 25-29)…
Small bubble of high pressure brings fair and mild weather for Christmas Day today. It will be very pleasant if you are traveling about or taking a nice holiday walk! The weather then starts to undergo a more significant change, first starting with a weekend that turns a little more unsettled as a wave of low pressure brings a risk of some rain later Saturday to early Sunday. Then, a push of much colder air, relative to what we’ve seen, arrives by Sunday night and Monday. Finally, a storm system arrives from the west on Tuesday and brings the first significant threat of frozen precipitation this season. Being 4 days away from the issuance of this blog update, it’s simply too early to try to pin point precipitation types and amounts. That will be brought into focus during the weekend updates…
TODAY – CHRISTMAS DAY: Sun filtered by high clouds. Highs 55-63. Wind W to variable 5-15 MPH.
TONIGHT: Mostly clear. Lows 35-43. Wind light variable.
SATURDAY: Increasing clouds. Highs 47-54. Wind light SE.
SATURDAY NIGHT: Cloudy. Chance of light rain. Lows 38-45. Wind light SE to S.
SUNDAY: Cloudy. Risk of light rain early. Isolated rain showers late. Highs in the 50s.
MONDAY: Mostly sunny and windy. Lows in the 20s. Highs in the 30s.
TUESDAY: Cloudy. Snow/mix/rain likely. Lows 20s to lower 30s. Highs 30s to lower 40s.

DAYS 6-10 (DECEMBER 30-JANUARY 3)…
A break December 30 after the system from the previous day moves away. A weak system may bring light precipitation for part of December 31. Looking for mainly dry weather and a more seasonable chill to start 2016.

DAYS 11-15 (JANUARY 4-8)…
Mainly dry weather expected with temperatures near to slightly above normal during this period.

93 thoughts on “Friday Forecast”

  7. Repost

    Here is the Tropical Tidbits 6Z GFS snow map

    http://www.tropicaltidbits.com/analysis/models/gfs/2015122506/gfs_asnow_neus_22.png

    The theme is a bit more warming of the column above, which many have predicted.
    Even though it redevelops to the South.

    The Euro redevelops it to the South, but keeps it relatively weak.

    http://www.tropicaltidbits.com/analysis/models/gfs/2015122506/gfs_mslpa_eus_20.png

    Here is the Euro snow map for a good chunk of it. Need to add 1-3 inches more
    on top of this.

    mgur.com/5PgSQXC

    JMA also wants to redevelop it to the South

    http://www.tropicaltidbits.com/analysis/models/jma/2015122412/jma_mslpa_us_7.png

  8. Repost

    Here is the Tropical Tidbits 6Z GFS snow map

    http://www.tropicaltidbits.com/analysis/models/gfs/2015122506/gfs_asnow_neus_22.png

    The theme is a bit more warming of the column above, which many have predicted.
    Even though it redevelops to the South.

    The Euro redevelops it to the South, but keeps it relatively weak.

    http://www.tropicaltidbits.com/analysis/models/gfs/2015122506/gfs_mslpa_eus_20.png

    Here is the Euro snow map for a good chunk of it. Need to add 1-3 inches more
    on top of this.

    imgur.com/5PgSQXC

    JMA also wants to redevelop it to the South

    http://www.tropicaltidbits.com/analysis/models/jma/2015122412/jma_mslpa_us_7.png

  10. I had a dream that Matt Noyes showed a 10 day forecast with all temps below 30 and chances of snow on almost every day and he said “what an end to 2015 and start to 2016 after what we just went through!” 😉

  11. Here is the Tropical Tidbits CMC snow map for the Tuesday event:

    http://www.tropicaltidbits.com/analysis/models/gem/2015122500/gem_asnow_neus_23.png

    Pretty Impressive, but event the CMC has a period of SLEET.
    Basically the column warms aloft during the transition period where the energy
    transfers to the coast. Then it changes back to snow when the coastal circulation
    takes over.

    Have a look.

    http://collaboration.cmc.ec.gc.ca/cmc/cmdn/pcpn_type_glb/2015122500/I_nw_EST_2015122500_108.png

    http://collaboration.cmc.ec.gc.ca/cmc/cmdn/pcpn_type_glb/2015122500/I_nw_EST_2015122500_111.png

    http://collaboration.cmc.ec.gc.ca/cmc/cmdn/pcpn_type_glb/2015122500/I_nw_EST_2015122500_113.png

    The GFS clearly has some sort of mix/changeover as well. I do not believe the Euro
    shows a changeover, at least in Boston, Perhaps to the South.

    In any case adding it all up here’s my take. Yes it is 4 days out, but this is a discussion forum, so here goes.

    Snow to start, accumulating 3-6 inches before mixing with and/or changing to sleet and possibly a brief period of Rain, followed by a period of snow where another 1-3 inches falls. Total accumulation 4-9 inches with total on the ground post-storm of 2.5 to 7.5 inches. Yes, it’s 4 days off and this could be totally and completely out to
    lunch, but it is my first take on this. I don’t think it stays all snow at this time.
    Will monitor for changes of course. Sorry about the rather large range, but it can’t be
    pinned down and even this might be a stretch.

    One more thought… The Tropical Tidbits uses a straight 10:1 ratio to computer their
    snow maps. The maps from Instant Weather are better as an algorithm is used to take into account temperatures in the snow growth zone. It’s not perfect, but it is better. Point being, Tropical tidbits snow maps need to be interpreted and generally not taken as shown. Sure they’re OK if the column is such that snow would be at
    10:1. How often does that happen? it is generally less or more. 😀

    Thoughts?

  15. Hard to stay away from the models even on Christmas 😉

    Interesting differences between the GFS and Euro. 6z GFS was pretty warm near the surface, showed a period of snow then a pretty quick change to rain. Cold at upper levels though. Euro is cold in the low levels, but warm at 700mb. Would be tons of sleet. Short term trend looks to be warmer.

  16. Once I think I am out you guys pull me back in. I tell my self every year I will it hug the models until I start to read this blog, then I can’t help my self . Lol merry xmass everybody.

  17. 12Z GFS is Warmer Still. Develops coastal farther North and later.
    Oh well, we had something to watch anyway.
    Let’s see what the Euro says a bit later. 😀

    1. It may be moving away from a snow event ….. But, I do think an inland ice or sleet event of some impact is in the cards. By inland, perhaps the Merrimack Valley, rte 2 corridor, CT valley …. Going to be difficult to dislodge the low level cold air.

    1. Confidence is growing on a small slushy accumulation mostly being washed away by rain by late Tuesday morning. North of the pike and west of 495 will be much different!!!! 🙂

    1. It’s going to come down to timing, because the later the precipitation arrives, the more likely any snow is very short-lived, and any rain/snow line will probably move rapidly northwestward later Tuesday.

  21. My concern is that the GFS may be too fast bringing stuff in here.
    If you want snow, you want the faster timing. The deeper we get into Tuesday morning before precipitation arrives, the shorter any snow period would be.

    1. Any thoughts TK on a follow up wave of low pressure, looks like the flow continues to parallel the east coast for a few days after the Tuesday system ……

      1. It looks very weak to me, and strung out as well. I don’t even think the initial bigger wave Tuesday will pack all that much punch. BUT, there may be a good amount of precipitation just from the difference between the warmth just to the south and the cold wedge over New England. Not sure how that plays out quite yet.

        1. Many thanks ! We have a couple trips this week, one early to Cape Cod, I’m not too worried about that direction and then, later in the week to see relatives in Lowell, which is the one I’d be more concerned about. I’ll be following your forecasts. 🙂

  22. If it’s possible, with some dim sun, very little wind and temps still near 60F, I think it feels even warmer out than it did yesterday.

  24. I will look at the 18z’s and the oz’s Lots of time left and also the 12zs were a fluke yesterday lets see if they are again this time.

  25. Timing too late. High in a bad position. And look how WARM the upper and mid levels will be. Not conducive to a snowstorm. Still details to work out with a few days to go.

  26. 12Z Euro takes primary storm over Wisconsin. Not the usual position for us
    to get a snow storm, that’s for sure. 850 temps still good, however, due to big High.
    Next frame has low(s) long gone. Have to wait for Wundermap to see what is really
    going on.

  27. One of the best Christmas’s in a long time. Both family’s are having dinners outside on decks. Absolutely beautiful!!! 60 degrees!!!

    Hope everyone is having a wonderful day!!

  29. Euro develops coastal was too late and too far North.
    Snow = SEE YA! Perhaps a coating, then sleet, RAIN.

      1. So basically whichever model has the least snow and the most rain will be the one you go with, even if they change places? 🙂

        1. No I think the majority of models are leaning more and more to a snow to rain. The euro is most reliable, but gfs can be sometimes right also. I’m sure you already know. 🙂

          1. GFS has been a little better overall through the Autumn with the general pattern and movement of features.

  32. As always, thank you, TK.

    Merry Christmas to all who celebrate.

    And season’s greetings to those who don’t.

    A peculiar Christmas day weather-wise. Bees, yes I said bees, flying from fresh blossom to fresh blossom in the Public Garden. I’ve already been bitten by more mosquitoes in December than I did all summer. Mild is an understatement. It was a late May day, basically. And yesterday, idem ditto. I know some are in their element. I think many are, in fact. The Public Garden was as crowded with families as it is on a typical summer’s day.

    Records were shattered across Europe today as the warmth continues to be the theme throughout most of the northern hemisphere.

    I’ve had my doubts about Tuesday’s storm. I think it’ll be plain rain at the coast after a brief mix. Effectively zero accumulation in Boston. There will be snow – and plenty of it – up north (wide swath of 6-12). However, I doubt anyone in SNE sees more than 4 inches of snow.

    What I do like is the pattern shift. It’s going to turn sharply colder and snow chances will correspondingly increase. Winter has just begun, but we need to be patient. We’ll get our snow. It just won’t be in December for many of us. Maybe New Year’s for all of us, and certainly snow some time in the first week of January.

    1. The pattern shift is only going to be good for 5 to 10 days, then we’re going to put some very warm air into western and southern Canada.

      1. BOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  33. Tk does it become mild, and temps back close to 50 degrees as we go into the 2nd week of January? I’m seeing subtle hints. Thank you!!

  35. Loved hearing the neighborhood sounds of children out playing like it was a Spring evening!
    Christmas Blessings to all!

  36. Just woke up from a 90 minute nap. Now some apple pie. Windows still wide open (have been for over 48 hours now) and temp still hovering around 9pm. Pretty neat.

      1. I really wanted a fire outside but by the time we all got home I think I was more exhausted than the kids…may have been a touch of emotional exhaustion tossed in with physical. Hope you had a great day, Keith

  38. All my nieces and nephews were all outside playing with all there new toys, everyone was happy 🙂 🙂 🙂 🙂

    1. Phew…for a minute there, I thought you were going to say you opened your pool 😉

      Glad you had a nice Christmas, Charlie.

    2. And if it was cold and/or snowy they would have been inside playing with all THEIR new toys and would have been happy just the same. It’s Christmastime. 😀

  39. Alright ….. Thru Dec 25th, Logan sits at +11.4F for the month.

    At midnight, it appears it was still 54F, so that sets today’s high already at +15F and with cloudiness and an eventual light east wind tonight, is there much chance going below 40F? I doubt it, so today’s coming in at +15F.

    Chance of a warm sector tomorrow and a +15 to +20F ….

    Anomaly probably sitting at +12F at end of 12/27 which is about 90% of December. 90% of 12F is 10.8F. I’d guesstimate that’s going to be right around where the final monthly anomaly ends up. Absolutely amazing.

    1. Have fun. I have golfed in every month of the year. Both up here and down
      the Cape. The coldest I played was 10 degrees at Brook Meadow in Norwood, either Jan or Feb, I can’t remember which.

  43. Just about ready to toss in the towel for the 29th. Just too much of a warm surge
    aloft, if not at 850mb, then at 700mb. Still likely to see some flakes and then sleet.
    Probably fairly brief, although it is still possible to have a longer period of sleet.

    We shall see.

    CMC gives us about an inch or 2 of snow/sleet.
    GFS gives us 3 or 4 inches of snow/sleet.
    Euro wants to give us about an inch of snow/sleet.
    Fim about the same, and inch or 2 of snow/sleet.

    Here is the GFS snowmap (Some of this is sleet for sure):

    http://www.instantweathermaps.com/GFS-php/showmap-conussfc.php?run=2015122606&time=PER&var=ASNOWI&hour=111

    I guess we have to wait some more and some more and some more.

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