Friday Forecast

62 Comments

7:37AM

DAYS 1-5 (DECEMBER 27-31)
Down the home stretch and to the finish line of 2019 the next 5 days, and we’ll have some active weather to follow after a quiet period. First, we have a warm front crossing the region this morning and producing spotty light rain, which is freezing on contact with untreated surfaces in portions of north central to northeastern MA and southern NH as temperatures sit at to slightly below 32 to start out the day. Use caution if traveling in these areas early this morning. The issue will quickly disappear by mid morning as the front goes by and temperatures go up, and just a few rain showers will cross the region during this afternoon as a cold front approaches from the northwest. This front goes through and clears the region out tonight and high pressure builds in with a very nice late December day on Saturday. High pressure shifts offshore Sunday, still not a bad day but clouds will be on the increase ahead of an approaching low pressure area which initially moves into the Great Lakes, but comes to a halt due to a high pressure road block in eastern Canada. This forces a redevelopment of the system along its occluding frontal system, which will take place over or just south of southern New England Monday through Tuesday, finishing off 2019 on an unsettled note. There will be enough cold air around for some possible freezing and frozen precipitation, favoring southern NH and northern MA, although at days 4 and 5 the details of this are rather uncertain. Also somewhat uncertain is if the precipitation will move out earlier or later on New Year’s Eve, which will impact travel and event plans for the final evening of the year. Forecast details…
TODAY: Mostly cloudy. Patchy light rain early morning with some freezing rain northern Worcester County through Merrimack Valley and southern NH. Isolated to scattered rain showers afternoon. Highs 44-51. Wind SW 5-15 MPH.
TONIGHT: Clearing. Lows 20-27. Wind SW 5-15 MPH shifting to NW.
SATURDAY: Sunny. Highs 42-49. Wind NW 5-15 MPH.
SATURDAY NIGHT: Mostly clear. Lows 30-37. Wind light variable.
SUNDAY: Increasing clouds. Highs 37-44. Wind SE up to 10 MPH.
SUNDAY NIGHT: Thickening overcast. Precipitation arriving west to east – mainly dry but possible snow/ice northern areas. Lows 32-40. Wind E 5-15 MPH.
MONDAY: Overcast with periods of rain, except some snow/ice possible portions of northern MA and southern NH. Highs 33-38 north, 38-43 south. Wind E to NE 5-15 MPH, higher gusts.
MONDAY NIGHT: Overcast with periods of rain except some snow/ice possible north. Lows 30-35 north, 35-40 south. Wind NE to N 5-15 MPH, higher gusts.
TUESDAY (NEW YEAR’S EVE): Mostly cloudy. Additional precipitation possible, favoring the morning. Temperatures steady in the 30s. Wind N 5-15 MPH, higher gusts.

DAYS 6-10 (JANUARY 1-5)
Split jet stream flow, polar near and north of the US/Canada border, subtropical mainly south of New England, and timing energy moving along each stream and any potential interaction will be difficult at best until we are much closer to any possible events, so the easiest way to sum up the first 5 days of 2020 is that we will have to watch 1 or 2 low pressure systems that may impact the region with some precipitation, but that we will also have a fair amount of dry weather as well, with temperature fluctuation. Early call is that potential low pressure systems time for January 2 and 4.

DAYS 11-15 (JANUARY 6-10)
Still with lower than average confidence leaning toward a colder and mostly dry theme due to domination by the polar jet stream and suppression of the southern jet stream.

62 thoughts on “Friday Forecast”

    1. No problem. I just wanted to throw out a reminder because in certain
      situations, the 10:1 ratio just doesn’t cut it and Monday/Tuesday may be
      one of those situations where the cold draining from the north is not
      thick enough to produce snow (at least farther South) but may be just thick
      enough to produce sleet. Should be interesting.

      1. You talking to me?
        I use IMGUR all of the time, yet when you post a link, it does
        not work for me, either here at the office or at home????
        Weird.

        Thanks for the alt link which I can see.

        1. Yeah. I was talking to you. You provide so many maps yourself saving me from looking them up. Least I can do is make sure you can see these!

  8. Thanks TK. Don’t read the below if you’re a snow lover 😉

    Could we be looking at another winter where the MJO is going to drive the bus? It sure looks that way to me right now. Current weak phase 6/7 state lines up well with the recent warm/quiet pattern and what’s expected through New Year’s. Looking like a brief soiree into the colder phases 8-2 for the first week or so of 2020. And then, potentially, a lengthy departure from the cold phases beyond then. All this to say, combined with a strong stratospheric PV that Dr. Cohen has been talking about, I’m more and more confident of January being a mostly warm month, but with at least one cold period over the first week of the month. In terms of precip/snow, if we don’t cash in during the coming cold period, expect the month to feature below or well below normal snow. And right now, to me the cold period looks more cold and dry vs. cold and snowy, as TK has also indicated. Better snow chances may be further south. What I’m less confident on is whether the warmer parts of January will be more warm and dry (as in the recent pattern) or warm and wet (with the potential for a lot of mixed precip events). If it does end up more active, it still leaves open the possibility of adding to the snowfall totals, especially inland.

    1. Well, you sucked me in. I sincerely hope you are incorrect, but it would
      NOT surprise me if you were, indeed, correct. Time will tell.

      1. I guess it would seem that winter will be making a very early departure in 2020. I do find it interesting that “dry” and “warm” tend not to coincide. Today and especially the Monday-Tuesday event speaks volumes, at least to me. Oh well. It wouldn’t be the first time during a winter.

        Thanks for the warning WxW!

        1. A mild January would not be anything close to a guarantee of an early departure of winter.

          Winter runs through mid-March.

  13. Word of caution – there are some 12z ECMWF snow maps circulating with 8-14″ of snow from Boston proper and north and west. Might I suggest using the snow depth maps or positive change snow maps.

    The ECMWF has used its typical bias to slow down and hold onto precip to its advantage this early winter season and has been more on then off when it comes to precip duration.

    On the other hand its temps have been too cold and overall pattern evolution has not been too good.

    I made fun of the GFS about 7-10 days ago in regards to its mid and longterm outlook. It has been closer to right the than the ECMWF. Yes a bit too warm but closer to right than what ECMWF was spitting out and frankly, what I was biting on.

    Overall the models have erred in this way – Any warm up has been too warm and cool down too cold and the duration of any cool down has been shorter than prognosticated and proved to be difficult to sustain.

    2. I agree, and I also am close to agreeing with WxW about the colder coinciding with drier, but we may end up with near normal snow from 1 or 2 events that are the “sneaky” kind during transitions. That’s what we have to watch out for. But yes you’re right about the model issues. Makes the forecast difficult but fun, if you know what I mean. 🙂

        1. 1, 2, 3, who knows. Maybe zero. 😉

          In fact we could get a sneaky snow event on the January 4-5 weekend if we’re not careful…. HAHAHA

  15. From NWS…

    precipitation.

    What remains unclear at this stage, though, is the southern/western
    extent of colder air/wintry precipitation, the depth of the colder
    air as well as precipitation-type changes/transitions. At the
    moment, do have some confidence for accumulating wintry precip at
    least for areas N/W of I-95 and the Mass Pike but may extend as far
    south as the Boston-Providence-Worcester-Hartford/Springfield urban
    corridor. Model forecast liquid-equivalent QPF appear substantial
    enough (e.g. ECMWF ensemble probabilities of 24-hr QPF of at least a
    half-inch liquid-equivalent valid thru 00z Tuesday are quite robust)
    that wintry-weather headlines are possible in some areas for part of
    this period; we caution that forecast snow and/or ice accumulations
    are at this stage low-confidence with significant change probable
    given above-stated uncertainty/sensitivity to precip-type changes.
    While a wintry mix/rain is an initial reasonable starting point
    given 925-700 mb temps, did note in some model solutions that low-
    level temperatures cool as heavier precipitation moves in, which
    suggests that evaporative/wet-bulb cooling processes at work that
    could be enough to force a period of accumulating snow at times as
    well.

  16. Dave – sensible weather for where most people live –

    The precip event 29th-31st. Long duration. Variety of precip types in SNE (rain predominant S&E, but only insignificant to light snow accumulations in those areas where most people live.

    Temps average near to sightly above normal into early new year, before turning colder, but for how long?

    Like December, monthly snowfall accumulation totals may be dependent on the 1st 15 days of the month.

  17. Mike Waunkum showed two scenarios:

    GFS – No snow anywhere in SNE. All in NNE.

    Euro – 3” for Boston, more inland.

    Waunkum would like to merge both models in his thinking.

    In past years I seem to recall the Euro always with the “warm” solution and the GFS with the “colder” solution. So far this winter, the reverse?

    1. GFS has typically always had a warm bias with winter storms. EURO the opposite but since the last updates the differences have become more defined dependent on overall pattern.

  22. Ensembles have been trending colder as the day has gone on, Let me know if the links work or not
    GEFS Break down by 00z, 6z, 12z and 18z Shows a cooler trend.
    https://imgur.com/a/oeCtVgt

    EPS break down
    https://imgur.com/a/isgcNmy
    Cut these amounts down a bit due to sleet which I believe is included. Plus the temp profile like several have mentioned before but this system has some surprises I feel. It will not take much to make it even colder than my current thoughts

  23. Reading all over social media how winter is over, same crap different year. We haven’t even flipped the calendar and people writing off winter.

    1. I’ll never get that. Year after year after year after year. And maybe I’d understand their still incorrect mindset a little more if we had no signs of winter yet, but we’ve had a rather snowy December. Winter weather showed up early. But wow, the pattern goes quiet for a while and “it’s over”. HAHAHA!

  24. At the beach, after sunset, the sand gets very chilly …… until you get to the sand that occasionally gets wet by the wave’s water climbing the sloped hill. That sand, compared to the dry sand is much milder, it’s a strange sensation. Then you step into the water and it initially feels cold. However, after a couple minutes, getting to used to it, it becomes apparent that the water is mild and probably still around 70F. My wife got in yesterday, but it was near sunset and I wasn’t up for that. I’m hoping to get in tomorrow or Monday. Beautiful Caribbean looking light blue water with a smooth sandy bottom.

    1. Do you give Bermuda a thumbs up?
      You are CHICKEN if you don’t get in that wonderful water. 🙂 🙂 🙂

  25. Working on the update. Was just a little lazy to start the day. I guess I earned it after the nonstop month. 😉

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