Tuesday December 8 2020 Forecast (7:56AM)

75 Comments

DAYS 1-5 (DECEMBER 8-12)

The circulation around an offshore storm brings some rain/snow showers to the South Shore of MA and Cape Cod for a while today before the storm moves away to sea. A weaker low pressure area will move rapidly east southeastward across the region Wednesday but at most will produce a few flakes of snow with its warm frontal passage during the day and a few rain and snow showers with its cold frontal passage during the evening. High pressure brings fair weather Thursday-Friday before the warm front from approaching low pressure brings cloudiness and a chance of some rain by Saturday. We’ll probably stay north of that frontal boundary but it will be too warm aloft to support any frozen precipitation.

TODAY: Mostly cloudy to partly sunny. Chance of snow and rain showers MA East Coast especially South Shore as well as Cape Cod. Highs 35-42. Wind NE to N up to 15 MPH, a few gusts to 25 MPH possible Cape Cod.

TONIGHT: Variably cloudy. A lingering snow flurry near Cape Cod early. Lows 18-25. Wind N to NW 5-15 MPH.

WEDNESDAY: Variably cloudy. Brief very light snow mainly north of Boston midday. Passing rain and snow showers possible, mainly late-day favoring areas northwest of Boston. Highs 35-42. Wind NW to W 5-15 MPH.

WEDNESDAY NIGHT: Variably cloudy with a risk of snow or rain showers early, then clearing. Lows 20-27. Wind NW 5-15 MPH, a few higher gusts.

THURSDAY: Sun and passing clouds. Highs 38-45. Wind NW 10-20 MPH, diminishing.

THURSDAY NIGHT: Clear. Lows 20-27. Wind W under 10 MPH.

FRIDAY: Sun and high clouds. Highs 40-47. Wind SW up to 10 MPH.

FRIDAY NIGHT: Increasing clouds. Lows 30-37. Wind SE under 10 MPH.

SATURDAY: Mostly cloudy. Chance of light rain. Highs 45-52. Wind SE up to 10 MPH.

DAYS 6-10 (DECEMBER 13-17)

Low pressure passes north of the region Sunday with a frontal boundary bringing a chance of rain showers, followed by clearing and a gusty breeze. High pressure is expected to bring fair and seasonably cool weather early next week. Next storm threat with rain/mix/snow comes late in the period.

DAYS 11-15 (DECEMBER 17-21)

A cold front may bring some mix/snow showers early or mid period. Next storm threat comes later in the period.

75 thoughts on “Tuesday December 8 2020 Forecast (7:56AM)”

  5. Thank you.

    I just woke up. Late for me but roads are a mess with black ice here. It’s too cold I think to snow. 27. What caused black ice ?

    10 car accident on 146 millbury. 146 shut down. 495 Milford area was a parking lot

    1. I think a bit of light freezing mist ?

      It generated at a height too low below where the snow crystals are made, so it fell as mist in an area well below freezing ?

      Could see he thinnest line of light echoes in that area on the radar.

      Thats a guess. I´d feel better if TK or others confirmed.

  6. Good morning, everyone, and thanks, TK…

    I concur about the black ice this morning. Road conditions really deteriorated into Middleborough. My students told me that a bus carrying students to the local voc-tec school crashed. I can’t find any report on that.

    I was listening to Rob Carolan on WSAR and he said that the obs and radars weren’t picking up the mist or fog that was freezing to the roadways, but he was getting reports of spinouts, crashes, etc.

    1. Oh no. I just gasped Captain. Millbury had a two hour delay. Sutton is full remote and teachers got an email not to go in

      A friend said freezing fog.

  7. I am somewhat surprised regarding black ice that far inland where Vicki is. From what the tv mets were saying, even Boston is not expected to see precip falling today. Only the South Shore/Coast/Cape.

    Of course TK does have precipitation in his forecast above. 😉

    2. Philip
      It was freezing drizzle . I was out in it at 3 am . I posted it earlier today on yesterday’s blog Freezing on my windshield. It was slippery

  8. Thanks TK
    From Judah Cohen
    After yesterday’s model runs intensified the calls to cancel #winter (I am looking at you EPS), there is some hope from this morning’s GFS ensembles. Another impressive signal for new #snowfall next week for New England.

  11. Cindy from channel 5 got a spotter call from pembroke ma the measurement was just under 1.5 inches of snow .

  13. 0z EURO has that feature around that time as well. Being so far out those will go poof but hopefully will reappear as we get close to late next week.

  14. I can confirm that there was pretty widespread freezing drizzle in the very early morning hours.

    In fact I didn’t realize how widespread it was until sometime later this morning because it was not on radar and the station distribution doesn’t really show what was going on. We even had a bit of minor glazing up in my area but it ended soon enough with the air done drying out enough that most of it was gone. That was not the case in areas for the south and southwest. So one can say that aspect of the forecast was kind of missed. Otherwise today’s forecast is on track.

  15. Thanks TK.

    No issues in my area this morning but lots of crashes and school delays reported in eastern CT and RI. I-395 was closed at one point with several vehicles off the road.

    The storm threat late next week (around the 18th) looks interesting on both the 12z GFS and 00z Euro.

    Dave posted the GFS…this was the Euro for the 17th:

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=prateptype_cat_ecmwf&rh=2020120800&fh=234&r=conus&dpdt=&mc=

    Euro had a near miss with an of shore coastal storm about a week from today as well.

    2. “Large differences are shown to occur in the numbers and sizes of sea-salt particles in marine air over the sea as the altitude, position, and the time of sampling are varied. Increases in the amount of air-borne salt near cloud base are related to increases in wind force at the sea surface. The greatest proportionate increase in particle number occurs at the large end of the weight range. Most of the samples reported here were taken near the Hawaiian Islands. The differences in nuclei number and size with increasing altitude in the lower atmosphere are similar in pattern in Hawaii, Florida and South Australia.

      It is suggested that bursting air bubbles in “white caps” on the open sea are a major source of the salt nuclei, and that a greater portion of the sea surface may act as a source of these particles during average winds than might be judged from the relatively small area usually covered by white caps.”

      So Scott mentioned above ‘no salt nuclei in Metro West” – I wonder how far this influence travels inland. Or when it is strongest.

      1. That’s not a given with the active pattern upcoming the next few weeks and a potential threat around the 18th.

      2. Above normal temperatures do not necessarily mean below normal snowfall.

        I repeat this numerous times.

  21. Most people reading that tweet you posted Mark with above normal temps no chances for snow. Wintry outcomes can not be ruled out in a warmer than normal pattern if everything comes together just right.

    1. Exactly. And that map looks like a torch but if you look closely we are in the area of “greater than 50% chance” of above normal. Some uncertainty there and even if it pans out, it does not mean it is above normal the entire two week period. Bottom line is the pattern looks active through Christmas and there will likely be opportunities for frozen precip mixed in there.

    1. I have been skeptical from the start with all these snowless/torch forecasts for January/February. So many other factors besides just your “classic La Nina” at play that can turn things around on a dime.

  23. Judah in his latest blog with increasing confidence of PV disruption in January and potential for colder weather in the East.

    -AO with Siberia and northern Eurasia getting very cold with building snowpack this month. This is a stark contrast to the last couple of years, especially last year when we had the very strong PV .

    1. Oh yeah, I remember you mentioning that at one point! I have posted other tweets from him before. Seems like a talented guy.

  26. Well that was interesting 12z Euro run…

    1. Farther south track with the weekend system and now hinting at some coastal redevelopment on Sunday which locks in the cold air and creates a mostly snow scenario for VT, NH, and ME. Who was it that said this might happen ?? 🙂

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=prateptype_cat_ecmwf&rh=2020120812&fh=120&r=conus&dpdt=&mc=

    2. Nor’easter on the 15th a week from today:

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=prateptype_cat_ecmwf&rh=2020120812&fh=180&r=conus&dpdt=&mc=

    It appears the latest Euro, CMC, and ICON are now focusing the threat next week around the 15th. Euro not showing much on the 17th/18th.

  28. Reasons for not trusting the blow torch snowless winter forecasts.
    La-Nina is moderate guidance now pointing to rapid weakening later this month/early January
    Looking at the ENSO region deep water anomalies you can see some warmth developing that could break to the surface
    TNH Pattern is positive 😉
    Asia looks to rapidly build snowfall this month,
    Possible disruption of the AO

    So many pieces of the puzzle and so many people focus on La-Nina but don’t look at east/vs west based, when does it peak, how quick does it weaken etc which all are important aspects of La-Nina. We have seen in the past 10 years that just because we have La-Nina or El-Nino or Neutral we might not see the so called “typical” weather patterns of that ENSO events as other factors are starting to become more influential due to climatic changes (I hypothesis this as I do not have any data to back it up). Such as the Blob which is not the PDO.
    .

  29. Thanks TK.

    This pattern is starting to look more typical of La Nina as the Southeast ridge shows some occasional signs of life, such as what’s coming for the weekend. However, so long as we hold this +PNA/-AO pattern, there will probably be occasional chances for wintry weather. As the tweet from Eric implies, it’s really other areas of the Northern Hemisphere that are cashing in on this pattern from a cold/snow perspective. But it still keeps the Northeast US in the mix for winter potential. This could end up being a long duration back-and-forth type pattern before the warmer, Southeast ridge dominated pattern becomes more dominant somewhere towards late this month or early next.

      1. I don’t know.. I’m usually a wise-ass. Not sure about just wise. 😉

        HAHA yes I will practice this myself.

        I have said over and over and over…
        Above normal temperatures in a winter month IS NOT AN AUTOMATIC below normal snowfall. That’s not how it works. Hypothetically, we could have a December that’s 10F above normal and 10 inches above normal on snowfall. All it takes is one event if it’s large enough.

        1. Ok, so is one of these upcoming events going to be large enough????? Ah, that is the question. At this point, I’d be happy with a medium event. 🙂

          1. Well I meant in terms of getting above normal snow for a month from one system. 😉

            And since the models have been and continue to be sucktastic I wouldn’t trust ANYTHING on them beyond a very short period of time. The only had to adjust about 500 miles on the system that went by this weekend. 😉

        2. Well, I am neither “wise” nor a “meteorologist”. 😉

          It is hard though to picture “above normal temps” and “snow” in the same mindset. But I suppose there have been Great Lakes Cutters with well below normal temps as well?

          1. One of our coldest months (February 1979) featured a series of Lakes Cutters. Snow was below normal yet it was a fairly active month.

  31. Long way to go, but the 18Z GFS has the 18th system
    as an Eastern Lakes Cutter and the 20th System as off shore.

    Just Can’t win. We’ll see how future runs handle all of this.

    1. I just hope I get one solid snowstorm before I go back to work so I can enjoy it at home with no stress .

    2. * Refer to TK comment above *

      For a 10-14 day forecast, I’ll take what the 18z GFS is offering at this point. The pattern looks good for chances the next couple weeks.

      BTW, it looks to be gearing up for a Christmas Day snowstorm at the end of that run as well 🙂

      1. I’ll still be off Xmas & everyone should be celebrating in there own home with who resides there so this would work for a lot of folks right .

        1. Agree. As much as I love snow, I have never wished for a big storm on Christmas Day. Too many families might not be together, including mine. But this year a snow might be nice. And as I write that I think of our first responders and front line workers who work that day and might well get tapped for a second OT shift if others can’t get in.

          So never mind …a dusting would be nice though

  32. The Wednesday forecast update won’t be available until later this morning or noonish after server reset.

    No big changes to the forecast anyway. Keeping the weekend forecast cooler than most media forecasts, and no big changes or new details to reveal about next week, but will send the update asap!

  33. Good morning. Guidance continues to be all over the place.
    Sit back and watch things unfold over the next couple of weeks.
    Just maybe, we get a white Christmas this year. Emphasis on
    Maybe.

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