Friday Forecast

245 Comments

7:27AM

DAYS 1-5 (DECEMBER 8-12)
A wave of low pressure will move up along a front offshore and will come close enough for the region’s first widespread snowfall of the season on Saturday and Saturday night. An upper level disturbance will bring additional snow showers during Sunday. The next storm threat is Tuesday but the track of this one remains uncertain. Detailed forecast…
TODAY: Sun and high clouds. Highs 38-45. Wind light SW.
TONIGHT: Clouding over. Lows 28-35. Wind light variable.
SATURDAY: Cloudy. Snow/rain developing in the afternoon, turning to snow most areas but remaining as mix/rain Cape Ann, immediate South Shore through Cape Cod. Highs 33-40. Wind light N.
SATURDAY NIGHT: Cloudy. Snow likely except mix/rain immediate coast especially outer Cape Ann and Cape Cod. Snow accumulations under 1 inch outer Cape Ann and Cape Cod, 1-3 inches South Shore and Logan Airport, 3-6 inches elsewhere. Lows 25-33. Wind N to NW 5-15 MPH.
SUNDAY: Partly sunny. Scattered snow showers. Highs 33-40. Wind NW 10-20 MPH with higher gusts.
MONDAY: Variably cloudy. Lows in the 20s. Highs in the 30s.
TUESDAY: Overcast. Chance of snow/mix/rain. Lows from the upper 20s to lower 30s. Highs from the middle to upper 30s.

DAYS 6-10 (DECEMBER 13-17)
Much colder early in the period, temperatures still below normal but not quite as cold later in the period. Best opportunity for additional snow is around December 15 probably from a clipper type system.

DAYS 11-15 (DECEMBER 18-22)
Still looking for the dominant trough, colder than normal temperatures, and a couple clipper systems.

245 thoughts on “Friday Forecast”

    1. At least that far since yesterday, more like twice that over 48 hours. Basically, we’ve gone from the western edge of the snow shield being at Boston 36 hours ago to being at Albany as it looks now, over 150 miles difference.

  5. Thanks TK.

    Would love to know the odds of Houston, Corpus Christi, and Jackson, MS getting their first accumulating snow before Boston. Thunder snow in Corpus Christi. Impressive. Still looks like we’re next. I think 3-6″ remains a good range for most of SNE, favoring the higher end for most places but closer to 3″ towards Logan and 1-3″ southeast MA. If 12z models bump the QPF up at all, might go to a 5-8″ range for some, but not confident enough on that yet.

    1. Quite rare since for many areas down there this is their second earliest measurable snow on record.

  6. Good morning and thank you TK. Looks like all systems are a go.
    Models are all in pretty good agreement. Looks like the snowfall forecasts
    are in line. I think that TK’s numbers are really good. I like his reference to right
    along the coast. Eric mentioned that last night as well and I totally agree.

    There was A December event a few years ago, where I thought it would NEVER
    rain at my house in JP, but it did for a couple of hours before flipping back to snow.
    I hope that doesn’t happen again, but I am prepared for that possibility. I love it when
    it is snowing here and raining at the airport.

    No need to post all of the snowfall maps as they are all very similar, however, I think
    it is worth noting the 3KM NAM Ferrier snow map as it is UP from yesterday, but
    still shows the effects of that warm ocean. Have a look:

    https://www.tropicaltidbits.com/analysis/models/nam3km/2017120806/nam3km_asnow_ferrier_neus_61.png

    It has “about” 2-3 inches for Logan and about 4-5 inches here in JP with 6 or a bit more farther inland. This looks to be the most realistic snow map of them all.

  7. Several high profile mets posting this morning about the lack of upper air soundings over Alaska right now. No 12z soundings there anymore due to NWS staffing shortages. I very strongly suspect that this has hampered model forecasts of the Arctic shortwave component of this event. It may lead to continued lower skill model forecasts than normal going forward this winter unless the problem is fixed.

        1. I assume you know this…NOAA IS the government. They are a federal agency under the Department of Commerce.

  8. Thanks TK

    Great forecast. Beautiful morning

    MamaMia, if you are reading, tonight we would all be at your snow hotel in Lexington for the rehearsal dinner.

    Tomorrow…..well, I never doubted the snow. Some things just are and I truly believed from quite a while ago this would be one of the, Kind of like the day of Macs memorial when a special friend and one whose forecast I trust implicitly told me that most had no idea how big a storm we had just missed 🙂

    Sorry…I will probably be full of memories for a couple of days and you all know I like to share them.

  12. One thing I would be guessing for immediate downtown is that system isn’t too strong thus keeping the impact of the warm ocean at bay.

    Still think it’s really exciting nonetheless!!

  14. 12z NAM hints at one concern I have, which is lift not being strong enough to generate heavy precip on the NW side of this system. If intensity is lower, that could also drop the ratios.

    1. This new snowfall calculator will get a big test during this event. IF it is correct, I can see us using it as the go-to snow tool this winter

      1. I spoke with one of my cousins a few years ago and she lives in Richmond VA and they received 14″ of snow and their schools were closed for an entire week. 🙂

  17. The chukchi sea, which is the sea just north of where the Bering Strait enters the Arctic Ocean is ice free, where there should be ice ……… and its snowing in places like Corpus Christi and Brownsville, TX in early December.

    2. The ice-free area is a long term thing, whereas the snow in the South is part of a shorter-term pattern.

  18. The NWS snowmap makes no sense to me. The “expected” snowfall for Boston is 6″ but a 1-10 chance it hits the high end which is listed as 7.” Then in places like Providence, the expected and high end are exactly the same. Way to confuse people.

    1. Those NWS maps should be taken with a HUGE grain of salt, to say the least. I can’t recall them ever being even close to accurate.

  19. It would be ironic if cities in the Deep South end up with considerably more snow than Boston…and all due to our ocean temps.

      1. I’m back! Remember me?

        I work with a guy in ‘Bama…has 3″ so far and thinks it will hit 4″ before it wraps up in the next three hours.

          1. Yup. Thanks! I am a known snow hater on this blog…BUT…since I am in between houses right now (great time to sell, not to buy), I am not worried about it like I usually am. No roof raking or added stress this year. So while I won’t say “Bring it on” I will say “No worries!”

  21. Correct. I was just commenting on the fact that the high end amount (10% chance of occurring) was only 1″ greater than the expected.

  22. TK how goes it? I moved during the summer so you won’t be in my backyard anymore, but I am still somewhat close (same town). Let me know when you are doing another Dunks meet.

  23. 12Z GFS KUCHER snow from College of DuPage site.
    These are down and really reflects the effects of that warm ocean.

    https://imgur.com/a/mq9zF

    Logan may be lucky to see 3 inches. They may come in at TK’s low range for them of 1 inch. 😀 😀 😀

    At my house in JP may only see something like 2-4 inches, according to this run.

    Of course we are not there yet and this could change a bit.

    I sure wouldn’t want to be giving numbers out to the public.

    I guess there is really good reason for the ranges.

    2. On the other hand, this morning’s CMC-RDPS / North America (mesh: 10 km)
      Has amount up there, granted this is 10:1:

      https://www.tropicaltidbits.com/analysis/models/rgem/2017120812/rgem_asnow_us_16.png

      But looking at this run, it keeps the R/S line South and East of Boston.
      I know the amounts are inflated, I post to show the R/S demarcation.

      Looking at precip type, it keeps it Snow in Boston. This is the closest the RAIN gets. It clearly marks the line:

      https://www.tropicaltidbits.com/analysis/models/rgem/2017120812/rgem_mslp_pcpn_frzn_neus_13.png

      So, we have some variability. There will be a R/S line. Where it stops, no body knows. 😀 😀 😀

  25. If anyone knows how to …..

    copy the frame from Instagram for the 12z GFS ….. surface temperature map … hr 36

    Its interesting to see where the 5c (about 40 – 41F) contour on the Massachusetts east coast is projected to be by tomorrow night at 7 or 8 pm (not exactly sure what time 00z is now after the time change)

    Many thanks !

  26. WeatherWiz…
    Irony: the house I hang at on Zion is going up for sale and the days there are numbered. I’m still at that DD off and on.

    1. HA that sucks. I am looking in that area…is it an active listing? If so I have likely seen it. I am on the Burlington line now.

      1. Oh sorry I saw your said “is going up.” If its a decent house I might be interested and they could save a realtor fee. Email me if it’s something you wanted to run by me. I assume you can see email addresses.

  27. We’ll see what the Euro says, but so far no big surprises in the 12z guidance. Track hasn’t really changed, a couple models dropping QPF just a tad. No changes to my thinking at this time of widespread 3-6″. Will continue holding off on the 5-8″ range I was thinking about going for along the 495 belt. Still think Logan can get 3″.

  28. JpDave says:
    December 8, 2017 at 11:10 AM
    Jackpot in Vicki Land!

    You have me at a loss for words. I LOVE it!

  29. Thoughts on timing of the heaviest snow–does it ever really get heavy? Driving from Natick to Amherst–leaving around 12:30 pm. Then driving home postgame–leaving Amherst around 5:30 pm.

  30. Here is the 12Z Euro Snow map. Again, this is a proprietary algorithm that is
    “supposed” to take into account thermal profiles.

    https://imgur.com/a/gql3d

    The detailed precip grid from my service indicates the following snow amounts
    for various locations:

    Boston (I presume Logan): 2.5 inches (right in line with TK)
    Jamaica plain: 2.7 (I cry FOUL on this. IF logan gets 2.5, JP gets at least 4 imho)
    Woburn: 5.0 inches
    Sutton: 6.4
    Marshfield: 0.1 inch
    Wrentham: 5.4
    Brockton: 2.8
    Brookline: 3.5 (interesting since I am 1/2 mile from Brookline city line.)

    That’s enough for now.

      1. That map actually looks pretty good given the set up.
        Perhaps still a little bit of wiggle room either way, but
        we’re getting close to show time. 😀

    2. Very happy !!

      I’m not ready for snow yet, I still like wearing sandals during the weekend.

      Christmas Eve and/or morning. And anytime during December or February school vacation. Got that atmosphere !?!?

      1. Sorry Tom, i want as many snow chances as possible, particularly in the week so the ski areas build up that snow pack 😉

        1. of yeah …. it can snow every day in northern New England from now to next May 1st if it wants to. 🙂 🙂

          1. snow= cancelled trips to Boston which = get more stuff done that i would of had to do over the weekends= more me time= more ski time= I want as much snow possible over the week.

      2. and what’s nice is …. my dad lives perhaps 5 miles inland from me, so it might be one of those events where I don’t have to deal with snow at my house, but can take a 10 minute drive and see 1-3 inches at his house and if my kids want to, they can play in it over there on Sunday.

          1. It can be a good indicator, especially for Logan.

            I figure by late morning Saturday, the Marshfield ob will be something like …

            overcast 38F/34F NE wind at 12

            and at that time, it will be interesting to see how much colder Logan and Boston’s suburbs are and what their reported wind direction and speed are.

      1. Brookline always seems to get everything more as more wind , more rain , more snow etc. we have a house over there to maintain .

      2. No. I only selected a few towns. If i select towns in the yellow
        area, I’ll get a whole bunch of 6 inches +

  31. Still thinking what I posted earlier, but I think the mid week system is going towards a more northern track with a light event if that but one storm at a time.

    1. Agree. Mid-week looks like a harmless clipper passed well to the North.
      Oh well. Clippers have to be just right.

      2. they can be sneaky, but i feel like this could be a reoccurring event with clippers getting their act just around the region and to the north. Pefect example is what the GFS is doing.

        1. Yup, could be. Then it would keep us dry and mostly cold, with milder interludes as the clipper passes to the North.
          “Hopefully, one will pass to our South OR pass just right to
          allow redevelopment to our South, else we will be
          bitterly disappointed.

  32. So I may be wrong but don’t you think we see most of it sticking after sun set and than it’s not far from over say 11 or so

    2. I wouldn’t count on it waiting until after sunset to stick. Remember, there is a very low sun angle. This isn’t spring.

  33. Ground is not all that warm and the sun angle is pretty much at it’s lowest, so it won’t take much to accumulate. I talked to a guy in Atlanta today at noon and it was sticking down there

  35. 18Z NAM is cooking and spitting out data already.
    It wants to start the SNOW somewhere in the 11 Am to Noon hour or thereabouts.
    AND it looks to get serious almost immediately.

      1. Often times it is, BUT, I have seen it spot on, especially this
        close to an event. So we shall see.

        IF the GFS stays the course, then perhaps the NAM is suspect.

        Also, here is another sanity check, the 3KM NAM Ferrier
        snow map:

        https://www.tropicaltidbits.com/analysis/models/nam3km/2017120818/nam3km_asnow_ferrier_neus_34.png

        Not for nothing, the 3KM NAM showed SNOW in Boston the entire event. That Ferrier map, must be factoring in some very high ratio snow/slop falling due to that warm ocean, even inland. I am not all that familiar with the ferrier method.

        In general I have found the Kuchera method to be quite
        reasonable. 10:1 methods are USELESS. Although the Kuchera is not perfect, it is far superior to the 10:1 method. I just wish I had more experience with the Ferrier.

        My personal gut feeling is that the Ferrier method “appears”
        to be over compensating. I guess we’ll find out tomorrow.

        I look forward to that. Something a little extra to go along with the season’s first snowfall.

  40. Unbelievable places in the south may have more snow than us after this storm system.
    I am not buying the slight uptick in the 18z NAM.

  41. Between the Euro and the new NAM, and just the way everything appears to be trending, I think amounts need to be upped a little. 4-8″ for most. 2-4″ along the east coast, mainly rain Cape/Islands. May see winter storm warnings go up for parts of the area.

    2. Just spoke to my coworker in Alabama…he said it’s still coming down and they are up to 7″. They were projected to get .5-1″

      1. Yeah, this was a major blown forecast for most of the deep South. Thing is, several of the models, the NAM especially, were showing the potential. But it’s so hard to get snow down there at all, let alone in early December, I think a lot of the snowy scenarios were written off, since that usually works down there. Not this time.

        1. Yeah he said they never get it this early and usually isn’t cold enough for snow until late January. He also said they always blow snow forecasts down there.

  42. Given heavy/wet snow, some branches still with leaves, and a number of weakened/broken limbs due to several high wind events this fall, I would expect some power outages with this event as well.

    1. Moving my mouse over the COD site Kuchera map, there is a SHARP
      gradient coast to inland. “about” 3.6 inches at Logan to about 6 inches
      in JP up to about 8 inches out around Sutton and 7+ most areas inland.

    1. Huh?

      Makes no sense to me, UNLESS, they issue one for inland MA
      as well.

      Sometimes I can NEVER understand their logic.

  47. Hi everyone. Time for me to come out of my summer/fall lurking mode.

    I’m a nervous nelly when it comes to driving in the snow. My commute tomorrow is sort of along the line between the storm warning and storm watch.

    I have to drive from Southie to Hanover for work around 9am. At noon I have to drive from Hanover to Hingham (the shipyard, not interior section). Late afternoon/early evening I have to drive to Chelsea (section closest to Logan) for a party.

    On a scale from 1 white knuckle to 5 white knuckles, how will this be?

    2. As a youth I’d drive anywhere. As an adult …because wisdom comes with age 😉 ….I do not drive in the snow. My concern if more other drivers but still

      Can you stop at any of those locations in a hotel or is business taking you to all?

      Safe travels and happy to see you here

      1. It’s only a 30 minute distance between each place so I’ll be ok. I’m just a wuss. I’m at the supermarket right now stocking up on bread and water in case I get stuck in my car for days and days!

        Just kidding.

  49. NWS maps are totally ignoring the ocean to our east…or their mets are very bad in geography. Boston totals are insanely high IMO.

      1. Any concern about those winds, especially NW, eating away at the prefix on the NE side, at least initially? aka bumping into a dry air?

        2. Not really. The air just outside the system is not super dry and the air flow not that strong.

  50. Good thing it’s a 384 GFS forecast: Highs upper 50s to lower 60s for Christmas Eve. 😉

  51. Is the system supposed to wrap up and head more NNE, or will it stay strung out? Reason I ask, it looks like it’s gonna slide harmlessly to our south. It’s missing DC to the south, that’s usually not a shoemaker for us in NE

    1. I think, as the northern stream feature gets closer, it will sharpen the flow, helping to move the precip into our area.

    2. It is strung out but has a nice rope-ripple into New England as the wave forms on the front and gradually strengthens. We’re not going to be seeing a bombing-out system.

      1. Yes, thank you again! It will be interesting which map will end up correct. We should know early Sunday morning. 🙂

    1. 0Z NAM looks like a piece of shit. Snow numbers are down, even with regular NAM, but the 3KM NAM is PATHETIC and I mean PATHETIC.
      Will this be a bust OR did the NAMS have GAS????

  56. Jpdave. U think the 3kNAME is pathetic. Wait until you see the latest gfs lol. It’s sad that parts of South Texas see more snow than us AND BEFORE us too

    1. Just looked at it. PUTRID.

      This has that BUSTORAMA look to it.

      I guess we’ll be now casting tomorrow and we shall see. After being truly excited this afternoon, I am back to ho hum big freakin deal. I think the WINTER STORM WARNING should be reduced to a winter weather advisory. Winter storm warning is simply NOT warranted in the least little bit. UNLESS something changes drastically.

      Perhaps a watch was required earlier, but a WARNING? GIVE ME A BREAK!!

      Let’s see what happens as it hasn;t happened yet. However, what Hadi noted and WxWatcher hinted at earlier today, most of the good lift looks to remain
      off shore. Not good if one wants an accumulation.

      Here is the GFS Kuchera Snow from the College of DuPage site:

      https://imgur.com/a/Gi25n

      Yup, that that has the makings of a true Winter Storm Warning all right.

  60. Out at the Nutcracker tonight and when i came home I didn’t look close enough at the 00z runs. Now looking it all over, certainly appears most of the lift is offshore. We should get several hours of heavy stuff but the rest of the time it will be light thus having a hard time sticking. Still like the 3-6 range from earlier today.

  65. Looking at the 6z runs of the American models warnings should be advisories. Both down with snowfall from 0z runs. Will see if that holds with 12z runs.

  66. Why don’t we give it a few more hours before you guys give up on the storm? The forecasts so far this morning are still the same at 3-6″. Besides, I brought my boots with me to work this morning. If it turns out I don’t need them on the war home then so be it.

  67. Latest HRRR indicates that it really won’t get going here until Noon-1PM. It shows the sparse coverage now, so radars are what they should be. The question is how much qpf can be generated.

      1. From what I am seeing, this smells like a BUST to me.
        The HRRR is just not looking good. We’ll see what the 12Z NAMs show. That should tell the story.

  71. As of 7AM Obs, closest snow reported was Cape May, NJ and Georgetown, DE. All stations in between reporting overcast.

  74. Overnight/morning guidance indicating that lack of lift may win the day with this storm. I’ll reduce my 4-8 back to a 3-6. From a forecast risk perspective, as this storm gets underway, it certainly appears the main risk is that we get less snow than expected as opposed to more.

    Watch any trends in the HRRR. It certainly is not too impressed right now.

  75. 11Z HRRR shows zilch at 11AM

    https://www.tropicaltidbits.com/analysis/models/hrrr/2017120911/hrrr_ref_frzn_neus_4.png

    then whamo, all filled in at Noon

    https://www.tropicaltidbits.com/analysis/models/hrrr/2017120911/hrrr_ref_frzn_neus_5.png

    And 10:1 snow as of Midnight tonight with it winding down already.
    NOT impressive at all. Not in the least. And this is 10:1. Real total would be like 2 inches, perhaps 3 tops.

    https://www.tropicaltidbits.com/analysis/models/hrrr/2017120911/hrrr_ref_frzn_neus_5.png

  76. If you look at the HRRR model there are places in SNE under an advisory that fall short of that criteria.

  77. I don’t understand why Taunton did what they did. To me this was an advisory level event with a general 3-6 inches although if the short range models are correct will be closer to the 3 than the 6.

  78. Updating shortly.

    Will be hanging onto the 3-6 max area with the emphasis on the 3 as originally stated whenever it was stated and wherever – probably in a comment and I’m not going to bother looking. 😉

        1. Yup, Certainly looks that way now.

          I will say, you NEVER bought into the hype that
          was flying around yesterday. 😀

  82. Some of you were wondering about the NWS snow forecast…
    This is how they handled it: They had in their discussion a phrase that said “Low pressure passing east of Nantucket will bring a general 4 to
    7 inches of snow northwest of the Cape Cod Canal later this
    morning continuing into tonight.” As of 6:55AM, the discussion was edited to say this: “Low pressure passing east of Nantucket will bring a general 3 to
    7 inches of snow northwest of the Cape Cod Canal later this
    morning continuing into tonight.”

    ALL FIXED!

  83. Sorry but it is comical to see you guys lose your minds because a strom may not produce as much snow as previously thought. Its just snow, thats it!!

  86. Here is the 12Z HRRR total Kuchera Snow for the entire event:

    https://imgur.com/a/3TJc6

    Placing mouse over boston, it showed a whopping 3.5 inches.
    An advisory level event, BUT certainly NOT a Winter Storm Warning Event!!!

    Those guys have to get back to reality. Not sure what they are smoking down there.

    1. It’s not a significant storm by any means and they’re committed so no biggie. They’re going to come somewhere in that range. Maybe off by 10% but who cares. Busting to me is when you put out a one foot storm and it snows 5″ in most areas.

      3,4,5 even 6″ pretty much all the same to me.

      1. What I am getting at with a bust is the full Blown Winter
        Storm Warning. There was NO NEED of that.
        I agree, 3,4,5 or 6 inches. What’s the diff. No big deal.

        BUT any of those figures does NOT constitute a WINTER STORM WARNING. That really frosts my ass. 😀

        1. Yeah, I thought they were stretching to begin with and just wanted to get one out. Who knows and we’ll see. This to me never looked like anything more than a stretched out front anyway. God knows there’s plenty of winter. Hasn’t even started yet.

  87. Snowing here with a dusting on all surfaces except roads. I was surprised as I thought nws timetable said noon

  91. I think most people listening to nearly a full week of intense hype expected to wake up to a “big snowstorm” today. I had several orders cancel everything for tomorrow – 2 days ago!!!!! That’s just how it is now….

    1. That’s pretty sad. The HYPE machine is PATHETIC.

      Tis that time of the year in New England. It does SNOW on occasion. What’s
      the big deal? Oh well.

      1. Oddly, I didn’t hear hype from any major station. I’ve been seeing 3-6 for days. I will continue to fault the individual for choosing to listen to u reliable sources.

        Patch put out a map yesterday. It’s headlines read up to 7 or 8. There was not one 7 or 8 on the map….just 2-6. Even with the headline, if people did what they should and looked a thing the map, they would know the headline was hype.

        2. Again, I want to add:

          The NWS issued a WINTER STORM WARNING
          that was totally and completely unwarranted.
          (now they event is unfolding, so to be fair there is
          a slight chance it will end up justified, but it doesn’t
          look that way. Even TK is saying 3s and 4s for final numbers)

          To me, that constitutes BLATANT HYPE.

          1. True, but how much of the public, other than meteorologists and weather enthusiasts follow their local NWS office like we do ?

  92. There was no real tip off from Marshfield this morning as temps were fairly uniform and winds were dead calm. Hmmm?

    1. It’s not that cold down here Philip or at least it doesn’t feel it . I was giving and estimate before 8 with no jacket on.

    2. All it will take here in marshfield is the development of north wind at 5 to 10 mph, which is off Massachusetts bay, and the temp will slowly climb. For Logan, different story. They will need a slight easterly component or an 020 to 030 direction to the wind and we’ll have to see if that happens.

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