Saturday Forecast

139 Comments

11:15AM

DAYS 1-5 (DECEMBER 23-27)
I know everyone is eager about the Christmas storm threat, but first we have something much more important in progress and that is an icing event for much of the region, save for a few immediate coastal areas and especially Cape Cod where temperatures remain above freezing. As of late morning, temperatures ranged from the upper 20s to very low 30s over the vast majority of the region to the middle and upper 30s along the immediate shoreline to the south of Boston and the lower to middle 40s over Cape Cod. A classic cold air damming situation is ongoing in which the cold air is trapped at the lower levels, most stubbornly over inland valleys. It’s easier to scour out this air, or prevent it from settling in, on Cape Cod, surrounded by water and where even a northwest wind, which keeps ocean influence away, is still able to bring modified ocean air in there. Very gradually the milder air will eat away at the cold, but it is going to take all day for a good part of the region to go above freezing, and some valleys may never even make it that far. The biggest push of “warm air”, in a relative sense, will take place this evening as we rid ourselves of the influence of the series of low pressure waves along the stuck frontal boundary and push a main cold front through from the west. The wind will attempt to turn southwest for a very brief time ahead of this but some of it may still ride up over dense cold air trapped at the surface (valleys most vulnerable, not to sound like a tape loop). During the day, episodes of rain/drizzle will be ongoing, with icing in all areas below freezing, with this area gradually shrinking as the temperature creeps up. A last round of moderate to heavy rain showers and even possible thunder may accompany the main cold front. And then… all of that exits and sets up what will be a rather pleasant Christmas Eve Day on Sunday by late December standards. It should climb above freezing pretty much everywhere, though not by more than about ten degrees maximum. This will be the best opportunity to get rid of the ice and snow/ice layer where it exists, but use caution as a temperature above freezing does not automatically eliminate slippery ground where ice exists. Now, to the next event. Models will be fine-tuning the details and yes, there will be a rain/snow line involved since we’re not going to be in air that is cold enough to guarantee a region-wide snow event from start to finish. The low track will be critical. Some short range guidance has it tracking over southeastern MA, which I think may be a bit too far northwest. My reasoning for this is a colder land mass than the model will “know of” and also that I believe it is over-forecasting the strengthen of the westernmost of 2 low pressure areas. This may look like a small model error if the thought process is correct, but could make the difference by 10 to 20 miles in a rain/snow line, which is significant when it comes to local impact. Also, there are solid signs of a rapid intensification of low pressure as it passes the region. It will be moving rather quickly, so it will not be a long-duration event, but it may end with a hard hit of snow for an hour or 2, even in areas that start out as rain. Can’t rule out hearing thunder in a situation such as this. But what about that rain/snow line? I think when precipitation arrives from southwest to northeast between 10PM and 2AM it will be in the form of rain along and southeast of a line from about Boston through central RI to southeastern CT, mix just northwest of this line, and snow beyond that. This line may waver around for several hours, but the progressive nature of the system and its rapid intensification will likely pull the rain/snow line eastward so Boston and Providence are snowing by or shortly after sunrise, it remains snow everywhere northwest of there, and turns to snow from west to east in the areas that it has been raining prior to the entire area exiting the region southwest to northeast by late morning. With this, I’d expect snow accumulations of 4-6 inches across north central CT, all of central to interior northeastern MA and southern NH, or basically the I-86 belt and central and northern portions of the I-495 belt, 2-4 inches along the I-95 belt including Boston and its immediate suburbs west and southwest, down through northern RI and parts of interior southeastern MA which would be closer to the 2, and then a coating to 2 inches from the South Shore through Cape Cod at the end of the event with the least amount across Cape Cod. The remainder of the day would be windy and colder with a few light snow showers around. Tuesday and Wednesday we will find ourselves immersed in a cold northwesterly fair flow delivering arctic air and presenting the chance of a few passing snow showers in otherwise mainly dry conditions. To the detailed forecast…
TODAY: Overcast. Freezing rain except rain immediate South Shore, South Coast, and Cape Cod, steadiest through midday with dangerous travel conditions, but most significant ice accretion in central MA and southwestern to south central NH where tree damage is possible. Temperatures very slowly rising to 27-34 interior, 34-40 coast, 40-46 Cape Cod. Coldest air remaining in deepest valleys. Wind light NW.
TONIGHT: Overcast evening with one more period of rain which may still freeze in deepest valleys. Slight chance of thunder during the passage of the last batch of rain. Breaking clouds overnight. Temperatures rise slightly to 32-37 interior, 38-43 coast. Wind variable to SW 5-15 MPH, shifting to NW overnight.
SUNDAY: Partly sunny. Highs 35-43. Wind NW 5-15 MPH.
SUNDAY NIGHT – CHRISTMAS EVE: Clouding over. Precipitation arriving late as rain Boston south, mix/snow elsewhere. Lows 26-34. Wind light E shifting to N.
MONDAY – CHRISTMAS DAY: Overcast through mid morning with snow except rain changing to snow southeast. A brief burst of heavy snow possible with a slight risk of thunder. See discussion above for expected snow accumulations. Breaking clouds and passing snow flurries midday and afternoon. Early-day highs 28-35 then falling temperatures. Wind N to NW increasing to 15-25 MPH with higher gusts possible.
TUESDAY: Partly cloudy and windy. Slight chance of snow showers. Lows in the 10s. Highs from the middle 20s to lower 30s.
WEDNESDAY: Partly cloudy and windy. Slight chance of snow showers. Lows from the middle 0s to lower 10s. Highs in the 20s.

DAYS 6-10 (DECEMBER 28-JANUARY 1)
Very cold with fair weather to start the period then 1 or 2 low pressure areas may impact the region with snow/mix (most likely snow). Lots of time to figure out details.

DAYS 11-15 (JANUARY 2-6)
Similar pattern, below normal temperatures, additional threat or 2 of a winter precipitation event.

139 thoughts on “Saturday Forecast”

  2. thank you.am mobile. will digest disvussion i fetsil lster.

    re roads
    main roads are fine.
    parking lots treacherous

  7. Guys I got the call to hear back in at 11 last night and wow everything was completely iced over it was crazy.

  9. Son just pulled in driveway. Put car in park and car slid back out onto atreet. He said Milford nh was snow last night, nothing early am, ice when he reached Ma and rain into RI

  11. Still a degree or two below freezing here. Son is going out shortly to friends house about a mile away…told him to be very very careful…first time driving in weather like this.

    1. If there is it would be a very narrow area and very brief. I actually think the temperature should be at or just above freezing where rain is, but we have the ground which will still have some ice/snow on it, which may be cold enough to freeze some rain on it. And just after the system we’re going to have a large temperature drop. There are folks that would rather see rain from that system, but I’ll tell you right now the best-case scenario is all snow.

      1. I’d rather see snow than this.
        I have to drive to PVD from my house about 1 pm Christmas Day and am wondering how much trouble I’ll have.

          1. I actually went to Walmart then to Millbury about 11:30. Just got back about 1:30. Roads that were treated are fine, just wet. Side roads in my town were passable, but not great. Sutton was very good. They do a better job in Sutton than Northbridge.

            1. You could have stopped for coffee and pepparkakor….I’m a hop, skip and jump from Walmart. Glad younhad safe travels.

  16. 20 years ago today began a storm that in the Boston area was forecast to be a few inches of snow followed by rain. However the computer models and forecasters buying them were in error, including myself, and many areas received 8 to 16 inches of heavy, wet snow. Traffic gridlocked and lasted for hours. A 10 minute round trip to pick up daughter up and grab dinner took 90 minutes.

    1. I usually remember wx events like that especially involving snow, but it doesn’t ring a bell.

      Thanks TK! 🙂

    2. I do not recall that. But Mac had gone to Roma to be with his family for Christmas so I was focused on being sad 🙁

      1. When I get home I am going to check what that 1997-98 winter was like for snowfall. Off the top of my head, I don’t recall getting all that much that particular season. I seem to remember the late 1990s not all that much overall compared to normal.

        1. The 1990s was the snowiest decade in Boston. The last 10 years (mid 2000s to mid 2010s) are the snowiest 10-year period in Boston.

  17. Very tough traveling coning for Xmas . Folks wanted this maybe next year they will think twice . From a professional snow removal essential employee this is going to be an issue

    1. SSK….for what it is worth….wanting it doesn’t make it happen. Not waning it doesn’t make it not happen. It will happen no matter what we do or do not want. However, what we do have control over is how we deal with it. Sort of like life in general. Making the best of something is not always easy…but in my experience, it is far better than making the worst of it.

    2. I just like the atmosphere of some snow falling when waking up X-Mas Morning. I do not think it will be that big of a deal, looks to end mid morning.

      1. ps, rather have the snow X-Mas than Saturday/Sunday next weekend as i have a party, but mother nature doesn’t give a crap, its gonna snow if its gonna snow, its gonna rain if its gonna rain, its gonna be freaking 5 below if mother nature wants to freeze my behind off. I hate this rain/ ice thing though, rather it be snow to cover what I call Crud snow, or rain to keep the roads safe.

    3. Nobody “wanted” an ice storm.

      We need to stop this thing about “rooting for” stuff. If you want something, great. If you don’t, great. Bottom line is the weather is going to do whatever it does. Somebody being excited about a winter weather event does not make the event worse.

      1. I don’t need another lecture from you as it’s quite obviously you and others seem to jump on me any chance you get . I’ll say whatever I want as long as it’s not disrespectful.

        1. “I don’t need another lecture from you”. Care to explain that one to me?

          I did not tell you you could not say it, but I was pointing out how it’s going to be taken.

          Go back and read your initial statement.

          “folks wanted this maybe next year they will think twice”? The insinuation there is that 1) someone wanted ice, and 2) because someone wanted it, it happened.

          And do NOT accuse me of jumping on you any chance I get.

          I don’t jump on anybody. But I will defend my blog if necessary. That said, you were not accused of doing something against the rules. My reply above had to do with pointing out that blaming people for wanting bad weather was not a fair assessment or statement. I’d have told this to anybody that said it.

          1. there is nothing wrong with wanting a white Christmas believe I get it . What Im trying to say is kind of like be careful what you wish for because if we get the snow and it’s more than a dusting it can cause issues that’s all . Merry Christmas.

            1. For the record, I don’t wish for anything, but what happens is still not linked to wishing. But it is what it is. Merry Christmas to you too.

        2. You are certainly entitled to say what you want…but blaming people’s thoughts or somehow shaming them for wanting snow just doesn’t make sense to me. I completely understand you wanting to be home for Christmas but it’s not anyone’s fault if you aren’t. Also I feel bad for people traveling on Christmas but at least it’s one of the most quiet holidays on the road. I could walk down route 3 in my boxers and no would notice (nor would anyone want to). As a quick aside I’d much rather have snow than the crap that’s falling right now. SSK I sincerely hope you get a full day with your family.

          1. I would be curious as to the last time you had to work on Christmas considering we haven’t had much frozen precip on/near that day in a number of years.

            1. Never in 46 years . I’ve been running like a mad man working 7 days a week since before thanksgiving I’m physically exhausted. I think I’m a little over sensitive right now and I apologize if some of my posts may have come out wrong . As far as Xmas goes it is what it is. I’d also rather have snow in the city than ice as last night was serious . I almost fell out of the truck getting out ( very dangerous) .

              1. Believe me there isn’t anyone here that doesn’t sympathize with the difficulty of what you do. Your work is important and appreciated.

                I get the sensitivity and frustration. Nobody is going to deny your right to feel that way. I hope things get easier soon.

    1. It will probably start as rain, end as snow, and freeze rapidly. All snow would be the best case scenario.

  20. Purposely left my driveway coated with 0.8 inch snow to make the ice removal easier. It’s going to work out. It will come off tomorrow midday.

  23. I remember that 12-97 storm. I was on my first job out of college working as an engineering inspector on a water & sewer main replacement job in Chelsea. We were working on a hill, and the contractor kept wanting to do “one more” service connection. Meanwhile, the road is closed, and the snow keeps pulling up and piling up. Couldn’t walk up the hill to take measurements, was freezing and getting soaked. Finally, after about 5″ of snow the contractor gave up and started to close up for the day. Then I had to drive back in the storm to Worcester. Took me about 2 hours, there was about 12″ of snow in Worcester, and it took me about another 45 minutes to find and dig out an on-street parking lot. Miserable would be a kind way of describing my mood by the end of that day.

    Ah good times, good times!

      2. I do remember that. It took Mac and two women from work in their cars who followed him maybe 6 or so hours to get home. He sat in one place on rt 30 over 128 for two hours

        But I also recall the snow squall we had in the early 2000s. I’ll see if I can recall the year. It wasthe worst up your way, TK. I was traveling to a meeting in Burlington. It took me 4 hours from rt 20/128 to Burlington. Over an hour alone was on 128 at rt 2 to the rt 4 Lexington exit.

          1. Many BPS kids didn’t arrive home until 8-8:30 pm IIRC. They had to stay put at their school for the streets to clear.

                3. I love it, MassBay. My parents were 1914 and told me the same.

                  I recall rt 2 being one Lane from belmont to concord and thought it was dirt packed but that may be what my mom told me it was when she was young

  26. Been scrutinizing some of the short range runs regarding positions of features upstream.

    The next 2 model runs should nudge the position of the low east for Monday.

    WRF series already has the rain/snow line further south and east (Boston as all snow) from the 12z data.

  29. 1. Tomorrow will be theo nly time that those with ice will be able to remove most of it, after that, some models are showing temperatures near 0 and highs not getting out of the 10s and 20s. meaning anything that falls on X-mas will be sticking around.
    2. I still have a bad feeling about the weekend storm. I think we will get at least something falling from the sky some where in New England because of it.
    3. We should hope that storm does not happen as big as it was being depicted, even us here in New England can not deal with that much snow all at once never mind the mid Atlantic. That will also effect many on the coast, even if its not going to give us precip, areas along the coast will likely still be effected because of the high tide.
    4. Models been crap past 3 days in determining positioning and speeds of features.
    5 and most importantly its my party and I do not want a big storm, and because I said this, it will happen 😛
    In other news, I do not believe areas west of I95 will see any rain on X-Mas. with a moderate snowfall. Light snowfall EAst of I95, I think the cape can get a few inches out of it as well. I do not believe it will be that big of a deal, should be able to get to your destinations.

    2. My only real concern is areas that start as rain Christmas will have a bigger problem due to dropping temps later. The all-snow areas will be more like “remove it and go about your business” kind of thing.

  30. Re-summarizing current thoughts…

    VERY slow improvement in the icing situation, obviously improvement comes first closer to the edge of the conditions and work toward the deeper valley areas where it may take until sometime tomorrow to loosen it up and get it off the trees/wires. Should have just enough hours of above freezing and a little help from low sun to do it during the day.

    White Christmas is a lock from just west and north of Boston northwestward. Wildcard from the city south and east is the rain/snow line Monday morning and its movement southeastward before the precipitation ends.

    After looking at the 12z guidance, no changes to the forecast above.

  31. Starting to get some branch/wire issues in parts of Worcester County. In Clinton, I can see a number of trees getting droopy (is that the technical term?!?).

      1. Still right around freezing here in Hingham…Roads seem to be better but wires (my 100 ft wire loop antenna) is drooping quite a bit. Except for the roads everything still has a coat of ice.

  37. We’ve lost a couple large tree limbs here in Wrentham. Quarter inch of ice. Very good thing that it isn’t windy, otherwise we’d be dropping tree limbs left and right. Pretty solid ice storm for this region.

  38. A dead tree just fell behind our house. It was well away from the house and needed to come down anyway – so I am not complaining.

    We have a crab apple tree near the house with lots of fruit on it. It is often covered with Cedar Waxwings eating the fruit. Today they are trying to pull the ice-covered fruit off with very little success. We saw one bird get the fruit in its beak and not be able to swallow it. It was even smashing the fruit against a branch in an effort to crack the ice!

  39. winter storm watches are up for Sunday night through christmas afternoon, if you want to call it that, they freakin merged it with the winter weather advisory, If you did not already know, I hate their new “simplified version” of the warning and advisory system, no real weather explanations, how the storm is behaving etc.

      1. 2-3 for me. Doable for son to get here. If not….we have done plan b for so many different occasions that I think we should write the book. I do hope all others arrive safely to their destination and have a joyous Christmas.

  41. Thank you, TK.

    Just finished helping someone move into their apartment. What a day to move stuff. We got it done, and didn’t get into an accident. The main roads were fine, but side roads and sidewalks were treacherous. I haven’t seen glaze like this in Boston for quite some time. Can’t say I enjoy the weather as unlike snow one can’t really walk around and enjoy it. It’s just very cold rain, the air is damp and icy. Feels colder than it would had it been all snow.

    1. The ice on the glass table on the deck started to drip a bit around 2:30. The ice on the metal arms of the chairs was not dripping at all. Now nothing is melting

      It is 32 on the dot

  47. I’d like to start to see the 0z guidance shift east or else I’ll start getting pretty nervous about the wetter solution

  48. Thermometer says 29 degrees im not the lowest of locations in my Town as Billerica is one giant hill, the lower area is be Nuttings Lake to the northwest of me, and a portion of pond street in central Billerica so I am going out on a limb to say those areas are cooler. Nuttings lake also had a bunch of ice on it last time I was in that area.

  52. 18Z GFS wants to give us a decent hit on New Year’s day. Looks like there is much
    to iron out with that time period.

  54. I find it interesting that Worcester and Springfield are not under any watch or advisory.

    Is the Christmas event yet another NNE Special?

    Boston needs 2.8″ to get to normal. May have to wait until next weekend?

    Normal for December = 9.0″

    1. Because they will issue watches etc. for areas they are a little more sure about. It may be adjusted a bit. A WSW is also depending on expected snowfall amounts.

  55. I am remembering a surprise Christmas snow in 1974.
    I seem to remember watching Bruce Schwoegler on the 11 pm Christmas Eve weathercast that year being disappointed with no chance of a white Christmas, and waking up on Christmas morning with a 3-5″ snowfall.

    1. Charles Laquidara on WBCN told his listeners to get up and slowly open the window curtains / blinds.

  58. Models look ugly for the coastal plain. Even out here in the hills I wouldn’t be shocked if it needed up on low end of range with plenty of mixing. The NWS discussion is just ugly for anything but widespread snow in SNE. NAM has been pretty consistently lower on QPF and warm. GFS has been a little colder and more robust but I’m sweating this one.

  60. Dave Epstein says “maybe” a half inch for Boston. AFAIC that isn’t even a lump of coal and it doesn’t even meet the criteria for a white Christmas (1″+). 🙁

    Hopefully we get snow next Satuday so Logan can at least get to normal for the month…assuming not OTS which wouldn’t surprise me with our luck sometimes. 😉

    1. At this point I have GIVEN UP on tomorrow. It is mainly a rain event
      for Boston. I am not pleased, but then again what can I do about it.

      Re: 12/31
      Ha Ha Hardy har har.
      ALL except the EURO have an Out to Sea scenario. Even the Euro has a pass
      well off shore, however, it features some heavy snow due to an inverted trough.
      (Well It looks like that to me anyway)

      Here are the surface showing the trough and the 24 hour snow map

      https://imgur.com/a/BebHP

      It will probably be totally gone by the 12Z run today. 😀 😀 😀

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