Thursday Forecast

89 Comments

2:28AM

DAYS 1-5 (FEBRUARY 15-19)
In the warm sector today with enough moisture for a rain shower risk mainly this morning and clouds being dominant for much of the day. Amount of sun determines whether or not anyone reaches 60, including if Boston’s record high of 61 is challenged. Two cold fronts come through Friday, one early preceded by rain, one late accompanied by a rain or snow shower, then much colder air arrives at night through Saturday. Will continue to watch a largely open wave of low pressure coming along and passing south of the region Saturday night and early Sunday. The impact remains in question, but still watching for a threat of a period of snow Saturday night. Odds favor this being a fairly minor event, but moderate amounts remain a scenario on the table so will continue to watch and hold off on solid numbers until next blog, if they become necessary. This system is embedded in an overall mild upper pattern so behind it we’ll observe an immediate moderation in temperature for the remainder of Presidents Day Weekend.
Forecast details…
TODAY: Mostly cloudy to partly sunny. Chance of rain showers early. Highs 45-52 coast, 52-58 interior. Wind light S.
TONIGHT: Mostly cloudy. Rain showers likely late evening on. Lows 43-49. Wind S to SW up to 10 MPH.
FRIDAY: Mostly cloudy with rain showers early, then sun and passing clouds. A brief rain or snow shower possible late-day. Highs 45-52 morning, then cooling through the 40s. Wind SW 5-15 MPH shifting to W and increasing to 10-20 MPH with higher gusts.
FRIDAY NIGHT: Mostly clear. Lows 13-20 Wind NW 5-15 MPH, higher gusts. Wind chill below 10 at times.
SATURDAY: Sun and high clouds day. Cloudy with a chance of snow at night with potential light to moderate accumulation. Highs 31-37. Wind light variable.
SUNDAY: Cloudy with a chance of snow early, then clearing and breezy. Lows in the 20s. Highs from the upper 30s to lower 40s.
MONDAY: Increasing clouds. Lows from the upper 20s to lower 30s. Highs in the 40s.

DAYS 6-10 (FEBRUARY 20-24)
Starting with much above normal temperatures followed by a trend toward more normal by the end of the period. Episodes of unsettled weather possible favoring rain showers through mid period and any type of precipitation later in the period.

DAYS 11-15 (FEBRUARY 25-MARCH 1)
Colder trend. A couple mix/snow events are possible.

89 thoughts on “Thursday Forecast”

  2. Good morning and than you TK.

    All models on board for a solid light to perhaps moderate event in the 2-4, 3-6 range.

    SREF mean 3.24 inches for boston.

  3. According to the tv Mets there not willing to put numbers on it yet saying it’s just not exactly sure yet . What I did Here is light if it happens and very fast mover gone by first light Sunday morning

      1. I’d give it another day before you start putting numbers on it as I don’t think this is the final say. If it does happen you’ll need to get up early if you want to see the snow flying . It doesn’t matter to me what it does

        1. With the timing, I agree.

          Starts around 10 PM and winds down around 7 AM or so.
          “About” an 8-10 hour event or so.

  6. Thanks tk.

    This sunday snow thing better move off south. I have a three day weekend. I only like potential systems when it might cancel work.

    1. I wouldn’t worry too much about it. Even if it lives up to maximum potential,
      it wouldn’t be a very impactful event. You can handle 5 or 6 inches of snow, can’t you?

    1. Perhaps preliminary prediction of Jet Blue flight at 7:30 am and road conditions from Natick to Logan at 5:00 am?

  12. I continue to favor a more suppressed/drier solution for the weekend. Do not be surprised if some of these robust models start to shift more southward. Some snow will be likely either way especially south of the Pike, but I do not buy the NAM right now.

    1. I can see that in the GFS and even the CMC.
      Not so much with the ICON. We shall see what the almighty Euro has to say.

      You have been pitching the farther South theme all along and you may end
      up being correct.

  14. Models continue to shift towards the Euro solution of highly anomalous, potentially historic warmth for the region next week.

  15. Pros for a system that delivers accumulating snow to at least part of SNE…
    *Ensembles favor enough amplification.
    *Tremendous amount of moisture for a system of its size
    *Enough cold air with the exception of the South Coast
    *Small area of upper divergence to enhance upward vertical motion and expand snow area

    Cons for a system that delivers accumulating snow to at least part of SNE…
    *Unfavorable overall pattern
    *Extremely progressive system that may not fully develop until after it passes

    Next week…
    It may look favorable for very warm weather on the upper pattern, but the surface may not cooperate for all that long. This may cut off the warm up a day to a day and a half earlier than a lot of forecasts currently indicate. Jury’s out here.

        1. Guidance almost always underestimates surface high pressure in Canada and its ability to generate a boundary that comes right down through the Northeast, and while the upper level pattern screams big warmth, the surface pattern is like… NOPE, SORRY.

  18. Preliminary forecast for snow event…

    Start time: 10PM-Midnight Saturday night.
    End time: 6AM-8AM Sunday morning.
    Accumulation: 1-3 inches southern NH and northern third of MA, 3-6 inches southern two thirds of MA southward except 1-3 inches immediate South Coast and under 1 inch Nantucket due to mix/rain in those locations.

    I still see enough evidence to shift everything south, or add to the precipitation amounts. So there is wiggle room in both directions as we sit 60 hours out from the start of the event.

    1. Why I post less and less. We agree too much….

      Sneaky jackpot would be NE hills of CT.

      Limiting factor to watch besides the obvious ones; even if thing seems like a “direct hit” it is going to be moving so fast with so much back side drying that it could shut off very quick without ever reaching peak here.

      1. Yes. I also agree on a potential “jackpot” area.

        No, this won’t be a major snowstorm by any stretch, but reaching its potential it would be a nice little though low impact event.

        2. Tk just a curious question . With so much uncertainty with this storm isn’t it early to be putting numbers on it I know it’s just preliminary. There is still = chance at getting zilch . The storm this morning was somewhere in California is that correct . Thanks Tk it’s just out of curiosity that’s all.

          1. I accounted for that in what I said. And also stated this is a preliminary idea. By definition that says it’s not necessarily my final idea.

            My general rule is 48 hours prior for #’s. I will go 60 hours if I have enough confidence. Today at 60 hours I feel that I have enough confidence but also applied the fact it is 60 hours and that wiggle room still exists.

        1. These are up there on my list too. They are the types of events that were complete surprises in the past. We see them better now. Granted this one can still miss, but just detecting the possibility is something we may never have been done in the days of the barotropic model. 😉

          1. The Average Verifcation Never model would have sniffed this out like a hound on the scent of prime rib and if not the No Good Model would have owned it no problem at 48 hours.

  21. Looking like a shorter duration of warmth on the Euro next week now with the mildest weather focused on Tuesday and Wednesday with widespread 60+ both days. Highs then crash back down into the 30’s on Thursday.

  23. It will be interesting to see what NWS does with advisories vs watches/warnings. To be consistent, I think they have to issue watches/warnings with the potential for 6″ even though it will probably be more at the 3″

      1. The last 3 times we’ve had a flat wave set-up like this, the NAM was closer than the GFS on amounts.

  25. I think TK summed up the pros and cons well earlier today. If it comes together right, snow will come down hard for a few hours Saturday night and we’ll get those 4-7″ totals. But I remain wary of getting enough amplification in the flow; I can see the jet dynamics helping us out, but the 500mb level is just about pancake flat. It’s not an easy forecast because it’s really a mesoscale feature that we’re having to treat like a synoptic feature. To avoid straying too far from the guidance consensus I would probably say something similar to what TK has, but shifting it all south by 20-30 miles. There will no doubt be more adjustments in both models and forecasts.

  26. Dave, the LFM (Limited Fine Mesh) model was around from the early 1970s to the early 1990s. It was a precursor to the NGM (Nested Grid Model) which was created later though they ran at the same time with the NGM proving to be the better of the 2. A little later came the ETA which then evolved into the NAM, which of course has been upgraded and refined since it made its debut.

  27. The temps may not have risen high today, but the dew points slowly have to almost 50F. It’s nice to have air that isn’t super dry. No static shocks today.

  30. Heading down to NC-RDU area and looking forward to some warmer weather and then back to PA for school vacation ski trip. Unfortunatley not a fun trip, but all enjoy the snow!

  31. Looks like 3-6 Boston through south shore less north and less cape . Extremely fast mover gone between 5-7 mid 4os Sunday’s afternoon so a lot will melt . Oh well no 3 day weekend

  33. Good morning. Winter storm watches hoisted from the Pike southward including Springfield, Worcester, Boston, and all of CT and RI. Excluding the Cape. Guidance still looks good for a moderate snowfall region wide but I think the NWS snow numbers may be an inch or so on the high side.

    2. I can see placing a watch just in case, however, I do NOT believe a Winter
      Storm Warning should be posted based on what I am seeing right now.
      If it changes, fine. IMHO, as we get the closer, the watch should be replaced
      by a Winter Weather Advisory for 2-5 inches.

  34. Although I reserve the right for further judgement after the 12Z runs, at this moment
    I am thoroughly UNIMPRESSED with tomorrow night’s snow event. It seems to be getting less and less with each successive model run and some models are more
    Underwhelmed than others. The most robust appears to be the 3KM NAM, and that
    has most to the South (see NWS map).

    3KM NAM Kuchera Snow (about 3 inches for Boston)

    http://maps3.pivotalweather.com/maps/models/nam4km/2018021606/060/snku_acc.us_ne.png

    10:1 Snow (again about 3 inches for boston)

    http://maps3.pivotalweather.com/maps/models/nam4km/2018021606/060/sn10_acc.us_ne.png

    Euro has 3.2 inches for Boston

    https://imgur.com/a/7hUo7

  35. I too remain generally unimpressed by tomorrow night. Models gradually trending towards the more suppressed solution that I’ve been pitching. Still looks like we get at least a little snow in here, with an outside chance of a more moderate event as well as the possibility it shifts even further south. 12z guidance should help narrow it down a little more. NWS numbers definitely seem high to me.

Comments are closed.