Thursday Forecast

195 Comments

7:27AM

DAYS 1-5 (FEBRUARY 4-8)…
Trying to fine-tune this forecast as a frontal boundary sits just offshore through early Friday, cold air slowly works in, and low pressure ripples move along the front. The final ripple will bring the threat of some accumulating snow to eastern and southeastern MA as well as RI early Friday, with a fairly sharp cut-off between accumulating snow and no snow at all. Current thinking places this line near the MA/NH border near the Merrimack River southwestward along the I-495 area and down to about northwestern RI. The greatest chance for significant snow will be interior southeastern MA where the combination of the coldest air and the heaviest precipitation is expected. This is not going to be a major snowstorm, but the timing is not the greatest as areas that do get the steadiest snow will likely have it occurring during commute time on Friday morning. Conditions will improve quickly Friday afternoon. Before all of this happens, the mild air that came in during Wednesday will hang around for much of Thursday. Additional patches of light rain are possible in RI, eastern MA, and southeastern NH during Thursday morning before it tries to clear out for a while ahead of the Friday morning event. By the time we get to the weekend, we’ll have a seasonably chilly and dry Saturday. A cold front will drop through the region from northwest to southeast Sunday, possibly producing a few snow showers, and reinforcing some colder air. Monday, the cold air will be established and an ocean storm will evolve but likely remain offshore far enough to spare this region impact.
TODAY: Mainly cloudy morning with additional rain RI through southeastern MA and a few rain showers elsewhere. Partial sun possible afternoon. Highs in the 50s through midday then cooling off slowly. Wind SW 5-15 MPH shifting to NW.
TONIGHT: Mainly cloudy. Rain/mix developing south to north overnight, changing to snow by dawn. Lows in the 30s. Wind NW to N 5-15 MPH.
FRIDAY: Cloudy through midday with snow, accumulating 1-3 inches except less than 1 inch northwest of I-495 north of the Mass Pike and 3-6 inches from the South Shore to eastern RI. A very small area of over 6 inches is possible interior southeastern MA. Clearing afternoon. Temperatures steady in the 30s. Wind N to NW 5-15 MPH with higher gusts.
SATURDAY: Mostly sunny. Lows in the 20s. Highs in the 40s.
SUNDAY: Partly sunny. Chance of snow showers. Lows in the 20s. Highs in the 30s.
MONDAY: Increasing clouds. Lows in the 20s. Highs in the 30s.

DAYS 6-10 (FEBRUARY 9-13)…
A trough of low pressure will remain in the area February 9 with additional storm development possible. Rain/mix/snow (depending on development and track) is possible on February 9. Windy and colder with snow showers possible February 10. Fair and cold February 11. Smaller system may bring some mix/snow February 12, reinforcing cold air for the end of the period.

DAYS 11-15 (FEBRUARY 14-18)…
Mostly fair weather with temperatures below normal to start the period then recovering to closer to normal.

195 thoughts on “Thursday Forecast”

    1. 1-3. Depends on how quickly it goes to snow after starting as mix. Leaning toward 1 or 2 for Woburn.

  3. I should clarify …..

    In the last storm, I did ignore the EURO and other models on the northern edge and it verified plus a bit more.

    So this time, I’ll go all in on what they are saying and hopefully, this will cause a bust in snowfall. 🙂 🙂 🙂 🙂

  6. Thanks TK. This is going to be a tricky forecast. Can’t disagree with yours or the NWS’s forecast at this point though. FWIW, to throw a couple more models in- the “parallel” ECMWF is pretty similar to the operational, an inch or two lower on average. Also, both the short range Canadian models are quite bullish, especially the high res 2.5km one. Takes 6″ of snow all the way back to Worcester, with 8-10″ for eastern MA. Would be curious in what the RPM shows; don’t have access to that one…

    In terms of actual meteorology: My question now is, with this more westward track, whether the highest amounts may end up more in the Boston-Providence corridor as opposed to southeast MA where mixing/low ratios will be a bigger concern. Some models are hinting at this. Should also note that most of the precip will occur during the day, which is a pretty big negative for snow especially in a marginal temperature situation. Something the models may not catch.

  7. Good morning again.
    For those interested I posted snow and qpf maps from every model imaginable
    on the previous post. I’m not about to re-post, so just drop in there if you would
    like to take a look.

    Re: System

    I don’t have a good feeling. Those High Resolution Canadian models are pretty
    decent. We can’t just chuck those out.

    I want to see the 12Z runs. I have a feeling they will be a tad more robust.

    Personally at this moment, I think Boston comes in at about 5 or 6 inches.
    Yes I said that. AND it “could” be more. We shall see.

    re: snowing during the day

    It is February 5th tomorrow. It is a Non-Factor in my mind. It is not March 29th.
    besides, I think intensity will be such that it would easily overcome that anyway.

    In my thinking, there are 2 possible limiting factors to the snow, other than straight
    qpf issues due to track etc.

    1. How long does it rain/mix before becoming all snow. In my experience with situations like this, it tends to become all snow faster than expected.
    2. How much does the warm ground waste snowfall before it accumulates. Again, my experience with these situations is not much as long as the intensity is there. Lighter
    snow, all bets are off, but with heavier snow, it will coat the ground and start accumulating very quickly.

    So all in all, I think the snow maps are reasonable.

    re: Ratio
    SREF has ratio between 5:1 and 10:1

    NWS says the main snow growth is at 600MB.

    700MB temps are in the range of -6 to -8 C
    500MB temps are about -14C

    So cut the difference and say 600MB is about -10C or there about.

    Check out this chart

    http://lukemweather.blogspot.com/2010/12/finallyhow-do-we-calculate-snow-ratios.html

    That temperature in the snow growth area “suggests” a ratio of about 12:1

    Even if that is wrong, I think we easily attain 10:1

    So these maps are not way off imho.

    Comments

    1. Old salty we shall see. I suspect than maybe a watch or warning may be in the cards for Suffolk county . Wind direction? What is the current temoature for the ocean . I also agree as I said the changeover time is crucial as this is I believe out of here by noon time if not earlier . Right now it’s darn right humid out there . How high does it I guess we will find out .

  9. I “may” be off my rocker, but it looks to me like the 12Z NAM has trended back South.
    Still early so I could be totally wrong.

      1. What is your prediction for school being held in Halifax tomorrow? I won’t hold you to it. 🙂 Just have to be prepared.

        1. I’d say 50-50 at the moment. This is just a guess on
          my part. NAM still running. Halifax looks to get
          in on the 6 inch or possibly 6+ inch zone.

          2. Thanks JPD. I would have two happy little boys if I surprised them with a snow day tomorrow. Me, on the other hand, not so much. 🙂

        2. Sue just my guess . If we stay in the 3-6 zone and that’s if and if the change over is before say 5am I think being a Friday and no School closings to date they may call it but that’s if above plays out . I think it’s done by noon time so it snows for say 7 hrs or so depending on the change over . If holds for south shore no school in my opinion only .

  10. NAM Jackpot Zone is from just N&W of Boston Southwestward down to about
    Providence RI and S&E to about Plymouth and all areas in between.

    You will readily see on the snow map coming shortly

  11. I am calling for a bust…no reason, no science, and I know all model disagree with me. Something just doesn’t feel right.

  13. One more frame on the NAM and I can post a snow map.
    Right now looking like a general 7-9 inches in the Jackpot zone. 😀

  14. What is the over/under on the time the NWS extends the watch and/or issues
    a Winter Storm warning up into the Boston area?

    I say 11AM 😀 😀 😀

          1. Sue I think that will be the case this time as well. I think some of those 8 and 9 inch amounts in southeast mass will not come true due to some rain at the onset of the precipitation.

              1. Obviously, need to look at more than the NAM, but all the trends have been for more snow and not less. 😀

      1. Perhaps ….

        in one sense, I like it when its already called the night before because it takes the chaos out of the following morning.

        On the other hand, unique to Marshfield and its proximity to the ocean, perhaps it takes a bit longer to transition from rain to snow in the morning and we can get into school. I’m guessing it should be done by 2:30pm.

    1. Nice Tom and thank you.
      I think you are correct. This is coming closer still.
      AND it will be more than a wave. This “could” end up being Serious.

  23. The 6Z Canadian High Resolution Model qpf in MM

    CMC-HRDPS / Quebec (mesh: 2.5 km interpolated to 5 km)

    http://meteocentre.com/models/get_accum.php?mod=cmc_hrdps&run=06&type=PR&hi=012&hf=048&mode=latest&lang=en&map=qc

    Please note:
    50 mm = 1.97 inch
    40 mm = 1.57 inch
    30 mm = 1.18 inch

    I believe it was WxWatcher that mentioned this model before.

    IF this is truly the trend, then we are going to be looking at a foot of snow.
    Wondering what the 12Z version of this run shows and also the 12Z RGEM which had
    10km resolution.

  24. Bernie Rayno’s video yesterday indicated he thought the snow would be much further west than models had yesterday. Looks like he was right on the money.

      1. Bernie is a great guy who loves to go out on limbs. When he picks a strong limb it looks great but sometimes those limbs are weaker than they look.

        To quote Harvey: “One must be careful how far one ventures out on a limb, because one may not get back.”

    1. Well that is a CRAP shoot!!!

      GFS takes main system OTS on Monday and develops a new one
      Tuesday and gives us something. 4 inches coast to 1 foot well inland.

      CMC is a swing and a miss

      Euro brings the OTS system close enough for about 9 inches or so.

      Throw a dart. They just don’t know yet.

      Something is “likely” to happen, but not certainties.

  26. Old salty I’m confused , on one post your saying jackpot area Boston than I asked the question if the southshore jackpot would shift north and you said duxbury / Plymouth is jackpot so which one is it. This is absolutely no disrespect at all Please I’m just confused. Thanks buddy

  28. I am now wondering if the more promising tomorrow’s storm gets, the less promising for Tuesday. My concern is…does storm #1 rob the energy for storm #2? Maybe with the exception of last winter, it is usually difficult to get back-to-back significant snow events just a few days apart.

    Your thoughts JP? 😀

    1. In this case, I honestly don’t think it has a bearing on it at all.
      I could be totally wrong. We will have new energy for the next system
      and this one will be long gone.

      The problem with the next one is how do the 2 streams phase or not?

      We shall see.

  30. NAM’s idea looks ok. We’ll have to see how long we start with rain/mix. May go to 1-2 495 belt, 2-4 95 belt, 4-8 city to SE MA but a rapid drop off at the Cape. Will make official adjustment at about 3PM.

  36. Now, the only thing that gives me a little pause in all of this is that, it’s still in the 50s out there. Even Burlington, VT is still 47F.

    There seems to be a dramatic temp drop northwest of that.

    Will that cold air make it into SE Mass in time ??? It appears from the models, yes ….

    1. YES, emphatically YES and with the expected intensity, it doesn’t even
      have to be all that cold at the surface as long as it gets in here above us.

      1. BUT wouldn’t that be the kicker of all kickers.
        Was going to be OTS and ends up as rain because cold
        doesn’t get in there. With this Winter, who knows. Hope not.

    2. It will make it but we will be close to not cold enough early and late in the precip. The intensity mid event will take care of that.

          1. Will be interesting. For some reason I can’t shake the feeling this won’t pan out that much…not sure why. When I am roof raking tomorrow I will freely admit I was wrong ha.

    3. My first boss and mentor said this about the second half of winter: “It’s easier to snow coming out of warm than it is coming out of cold. “

      1. Not sure which one you meant. But in case you were asking I can see 3 to 5 for the city and 4 to 6 for your area based on current ideas of how it pans out.

  39. I have to say that Twitter and Facebook are rather quiet about this snow event. I am smelling a bust also. Just out of pure gut feeling.

    1. the reason is because it really just happened in the past 24 hours that it has become interesting, this thing was suppose to go well out to sea, Now not so much, just wait till 3pm, then you will see plenty.

  40. I do not smell a bust, quite the opposite. This has been(sadly) one of the most exciting surprises of the year. GFS also develops another shortwave on Tuesday

  41. Is it possible the storm for tommorow keeps trending west leaving areas west of Boston being the jackpot, while boston have mixing issues?

      2. It’s hard to believe it’s going to snow tomorrow with how warm it is now. I don’t think Boston will see mire than 3 inches, i hope i am wrong.

    1. GFS from 12z sends a broad low well out to sea late Sunday into Monday and brings a moderate snow/mix event into SNE early Tuesday.

  43. Anything is possible, but I think as long as the precip comes down hard enough it would negate any surface temp issues as mentioned by OS.

  45. Another reason there’s not much twitter/facebook noise, this won’t be a big event. After the blizzard a couple weeks ago, 4-6″ of snow isn’t much to write home about. We’re excited about it since this has potential to be close to our biggest event of the winter to date, at least for Boston.

  46. Tomorrow’s event looks a lot like a March storm: Mild today, colder tomorrow with snow and mix, relatively mild on Saturday (snow may melt away rather quickly). Next week’s possibility is more intriguing in my view as a push of somewhat more consistent cold air moves in.

  50. BZ now on board for a wide area of 4-8″ snowfall including Boston. Big difference from this mornings C-2″

      2. Completely disagree acemaster,, most schools will be closed tomorrow. Mark my words. Many will cancel before the 1st flakes fall. I don’t agree with this philosophy, for one a cancelled school day is never made up, and though they say it is. A made up day in late June has no substance to learning as they would tommorrow.

        1. I agree days are not made up. Days at the end of the year are most always fluff days.

          However, an injury or worse is not made up either and I’ll go for the safer of the two.

          Also, we spend more hours in class than the best school systems in the world (of which we are not one). I’m not worried about a school day – other than for kids and teachers who end up being stuck there.

      3. I suspect it will depend heavily on the timing. This morning Chris on 7 said it would move very quickly (which I believe TK said although I may be wrong). As a result, Chris said (TK did not) that there could be quick one inch an hour accumulations during rush hour.

        Even with a few inches, buses may not be able to handle that.

  51. If it were me, I would have a 2 hour delay, and extend the school day 2 hrs. Done!! Fixed!!! Snow will be finished by 9-10am, and the sun will be poking out by noonish

      2. IMO roads will be clear after 9-10am, and with higher sun angle, temps in the mid 30’s, the overall impact on roads will be much less. Just my opinion. I am different though as Dave is different he says a major snowstorm is 18+, I see folks say roads are bad, but then when I have to drive during snowstorms which is every storm, I don’t think there bad at all. It’s all in the eye of beholder. 🙂

    2. The vast majority have been doing that for quite a while. Some – Framingham included – has far too large a population to do so safely although I do believe they tried it one day last year for the first time ever.

        1. 🙂 My guess is you will be right with the delays and no cancellations if this is in and out early enough to get roads and sidewalks cleared for a delayed start. Maybe not on south shore – sorry Tom 🙁

  52. Tk I have a question, with temperatures never going below freezing, and actually most of the time a little above, and with rain to start is it possible that it takes a lot to accumulate. The ground is so very warm. It’s going to have to snow very heavy?? Thank you!!

  54. Schools will close tomorrow. Timing is such that it’ll effectively be an all day event. Shouldn’t be a hard decision, especially given most districts haven’t had to burn a single snow day yet. As Vicki said, better safe than sorry. Besides, I think a snow day here or there is a good thing for the younger kids. Especially on a Friday 🙂

    I like the idea of a broad 4-7″ swath across most of central/eastern MA, less towards the Canal and maybe very little outer Cape. Highest WSW of Boston. Even out towards Worcester could see near 6″. I think even on 1″ QPF (on average), mixing and ground warmth issues will make ratios for the whole event around 5:1, including the mix/rain period.

  55. Charlie, you will not have sunshine and clear roads by 10AM. Heaviest snow will be over by late morning but does not taper off until afternoon, esp. across eastern MA.

    This thing will be cranking around the morning commute and I would expect widespread cancellations.

    2. I mentioned that issue for the Cape myself earlier. Temps marginal at surface but will drop below 32 during heavier snow which will accumulate quickly where the max area is. Timing is everything. Closings will work better for some communities where delays will suffice in others. We can’t just blanket this with one approach due to variability from place to place. I do agree that roads will recover quickly, however.

  59. Regarding next week:

    12z Euro maintains the powerhouse ocean storm Monday, brushing the Cape Monday night. The Tuesday system is much closer, in fact a near perfect track, but weaker. Would be a moderate storm event, similar to what the GFS is showing. The more that first storm cranks up over the ocean, it saps the energy away from the next system. They are just too closely spaced apart.

  60. Euro now making more sense. yesterday was just a bad day for it. We all have one of those.
    here is the positioning. I do not have the amount of water but looking at it. Probably a moderate snowstorm
    http://tropicaltidbits.com/analysis/models/?model=ecmwf&region=us&pkg=z500_mslp&runtime=2016020412&fh=126&xpos=0&ypos=0
    then bends northeast.
    http://tropicaltidbits.com/analysis/models/?model=ecmwf&region=us&pkg=z500_mslp&runtime=2016020412&fh=126&xpos=0&ypos=0
    pretty typical for a northern stream based system

    2. Watch that low over the Great Lakes and how it may interact with the parent low over the atlantic.

      1. that system over the great lakes could give it more energy or push it further out to sea. or drag it in closer, who knows. lol. and the storm of the southern stream could slightly effect it.

    1. As for that Tuesday storm, according to TK it is going to depend on the northern and southern streams merging or remaining separate. I thought it was all about the energy as well.

    1. Indeed, there is zero ice on the bodies of water close to my apartment. Hard to believe it will snow tomorrow. That’s what makes this a `March’ storm, in my opinion. I prefer the `February’ storms with cold before and after, and I think we may get one early next week.

  63. The clouds were starting to break up a bit when i was out at lunchtime and the temps were starting to creep up a bit, now all cloudy

        2. Watch the dewpoint.

          Certainly, the temp matters some, but the dewpoints are falling rapidly, which will allow the temp to fall once the precip commences.

  64. There is a serious pipeline of moisture down the coast along the front. Even if no distinct “storm” forms along it, we get some good QPF

  66. Tk I’m seeing subtle hints that it could very well be still raining at 3-4-5am and start mixing with snow around 6am, and not completely changing to snow until 6-7am??? Temps around midnight will be around 40-41 degrees. Any thoughts tk?

    1. And the snow accumulation projections have come down in Marshfield and Plymouth, yay !!!!!!

      Oh please yes !!!

  69. WINTER STORM WILL BRING HEAVY WET SNOW TO MUCH OF SOUTHERN NEW
    ENGLAND LATE TONIGHT INTO FRIDAY…

    CTZ004-MAZ012-013-015>018-RIZ001-002-050345-
    /O.UPG.KBOX.WS.A.0002.160205T0600Z-160205T2000Z/
    /O.NEW.KBOX.WS.W.0002.160205T0600Z-160205T2000Z/
    WINDHAM CT-SOUTHERN WORCESTER MA-WESTERN NORFOLK MA-SUFFOLK MA-
    EASTERN NORFOLK MA-NORTHERN BRISTOL MA-WESTERN PLYMOUTH MA-
    NORTHWEST PROVIDENCE RI-SOUTHEAST PROVIDENCE RI-
    INCLUDING THE CITIES OF…PUTNAM…WILLIMANTIC…MILFORD…
    WORCESTER…FOXBORO…NORWOOD…BOSTON…QUINCY…TAUNTON…
    BROCKTON…FOSTER…SMITHFIELD…PROVIDENCE
    245 PM EST THU FEB 4 2016

    …WINTER STORM WARNING IN EFFECT FROM 1 AM TO 3 PM EST FRIDAY…

    THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A WINTER STORM
    WARNING FOR HEAVY SNOW…WHICH IS IN EFFECT FROM 1 AM TO 3 PM EST
    FRIDAY.

    * LOCATIONS…NORTHEAST CONNECTICUT…MUCH OF CENTRAL AND EASTERN
    MASSACHUSETTS…AND NORTHERN RHODE ISLAND.

    * HAZARD TYPES…HEAVY SNOW.

    * ACCUMULATIONS…4 TO 8 INCHES…WITH THE HIGHEST TOTALS NEAR
    INTERSTATE 95.

    * TIMING…RAIN BEGINS LATE TONIGHT AND CHANGES TO SNOW EARLY
    FRIDAY MORNING. HEAVY SNOW IS EXPECTED DURING THE FRIDAY MORNING
    COMMUTE…BEFORE TAPERING OFF AROUND MIDDAY FRIDAY.

    * IMPACTS…HAZARDOUS TRAVEL…ESPECIALLY DURING THE FRIDAY
    MORNING COMMUTE. PLACES THAT RECEIVE MORE THAN 5 INCHES OF SNOW
    ARE PRONE TO ISOLATED POWER OUTAGES FROM DOWNED TREE LIMBS OR
    WIRES.

  71. I believe snow will have hard time sticking at first, which should limit snowfall amounts, unless it snows heavy for a while from the beginning. Tk do you think the models put warm ground temperature into consideration when foecasting the snowfall total? I know they put snow ratio ito consideration but how about the really warm ground?

  72. By the way …..

    The 850mb temps near and just north of New England in the end of this event EURO run are frigid !!!!!!!!!!!

    1. Wait it’s suppose to be cold in February??? HA. Are you talking about temps next week? I know the weekend is warm correct?

      1. Totally agree, but nothing like last year at this time, I just looked at pics of last year at the sametime, om gosh WW, it looked like Siberia. Also would like to add after this period of cold, it wants to become somewhat milder again especially towards the end of next weekend. We shall see

  74. Good afternoon,

    Well not surprised that Boston is in the Winter Storm Warning area.
    What time did they do it?

    Here is the latest 18Z 32km NAM snow map. Stays the course

    http://www.instantweathermaps.com/NAM-php/showmap-conussfc.php?run=2016020418&time=PER&var=ASNOWI&hour=036

    12km NAM

    http://www.tropicaltidbits.com/analysis/models/namconus/2016020418/namconus_asnow_neus_13.png

    4km NAM

    http://www.tropicaltidbits.com/analysis/models/nam4km/2016020418/nam4km_asnow_neus_12.png

    WRF_ARM

    http://www.tropicaltidbits.com/analysis/models/wrf-arw/2016020412/wrf-arw_asnow_neus_48.png

    WRF-NMM

    http://www.tropicaltidbits.com/analysis/models/wrf-nmm/2016020412/wrf-nmm_asnow_neus_48.png

  76. We should bet on how many times Channel 7 changes their snow maps. I think it’s been 4 times since 8am so far.

    1. 4 has done the same. I just looked at four and darn near fell off my chair. I was in small amount of snow this am and now am in 4-8. I would suspect it is because things are changing.

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