Wednesday December 30 2020 Forecast (7:34AM)

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DAYS 1-5 (DECEMBER 30 – JANUARY 3)

After much of the region saw a very nice sunrise, an abundance of high & mid level cloudiness will limit sunshine today as a warm front moves across the region. The precipitation associated with this front, which is not too prominent anyway, will pass north of the WHW forecast area. This warm front is parented by low pressure which will be passing north of our area tonight and dragging its trailing cold front across the region Thursday morning, bringing with it a period of rainfall before drier air returns during the day from northwest to southeast with some partial clearing occurring. High pressure, initially under-forecast by guidance, will be quite strong as it builds across eastern Canada and exerts its influence on us here, bringing cold and dry weather for New Year’s Eve & New Year’s Day. If you recall, just a few days ago, most guidance had been calling for a repeat of the warm/set scenario of Christmas Day, but this is a vivid example of why we don’t just look at the models and make that the forecast. The storm system that this guidance was trying to track so quickly well northwest of our area is going to be a little slower-moving, and track much further southeast, passing right over the area early Saturday. Ahead of it, when its precipitation shield arrives during Friday night, it will likely be cold enough so that it begins as snow & sleet in some areas, especially away from the coast, but warmer air moving in aloft will change this precipitation to rain, although a period of icing is quite possible over interior locations, especially valleys, where surface cold air is always a lot harder to dislodge. Eventually, as low pressure moves east of us during Saturday, drier air will return, and we’ll see improvement in the majority of the region before the end of the day, but it now appears this improvement will be rather short-lived, into the first part of Sunday, before follow-up low pressure tracks south of the region, but close enough to bring its envelope of precipitation into at least the southeastern portion of the area by Sunday night. The timing and precipitation type details still need to be worked out, but odds favor a little bit more snowfall coverage with that one, provided it gets far enough north.

TODAY: Sunshine limited by high & mid level clouds. Highs 33-40. Wind W up to 10 MPH.

TONIGHT: Mostly cloudy. Rain, may begin as sleet, arriving in southern NH and northern MA pre-dawn. Lows 25-32 evening, rising through the 30s overnight. Wind S under 10 MPH.

THURSDAY: Cloudy morning with rain progressing southeastward through the region. Mostly cloudy to partly sunny afternoon. Highs 42-49. Wind SW 5-15 MPH shifting to NW.

THURSDAY NIGHT (NEW YEAR’S EVE): Partly cloudy. Lows 18-25. Wind N 5-15 MPH evening, diminishing overnight.

FRIDAY: Sunshine fading behind increasing high cloudiness. Highs 32-39. Wind N up to 10 MPH.

FRIDAY NIGHT: Thickening overcast with snow/sleet northwestern areas and mix/rain southeastern areas arriving from southwest to northeast, changing to rain except possible freezing rain interior valley locations. Lows 30-37. Wind N to NE up to 10 MPH inland and 10-20 MPH coast.

SATURDAY: Cloudy with areas of fog and a chance of rain in the morning. Breaking clouds in the afternoon. Highs 45-52. Wind NE to variable 5-15 MPH becoming W.

SATURDAY NIGHT: Partly cloudy. Lows 25-32. Watch for black ice formation. Wind W up to 10 MPH.

SUNDAY: Partly sunny. Snow/mix/rain possible at night. Highs 35-42. Wind N up to 10 MPH.

DAYS 6-10 (JANUARY 4-8)

Low pressure passing southeast of the region may impact the area with snow/mix/rain January 4. High pressure builds in with fair weather January 5. Weak system may bring a few rain/snow showers, milder on January 6. High pressure builds back in with fair weather January 7. Next threat of unsettled weather comes from passing low pressure about January 8. Temperatures variable, not too far from normal.

DAYS 11-15 (JANUARY 9-13)

Stronger indications of a blocking pattern setting up during this period. Generally dry and seasonably cold weather to start out in our area, but a chance of some unsettled / wintry weather comes later in the period.

62 thoughts on “Wednesday December 30 2020 Forecast (7:34AM)”

  1. Thank you , TK.

    Almost got to see that sunrise this morning, sounds like you did? Was aiming to go see it over the water, but the cold won out. Last night I went to see the moonrise and that icy wind was fierce!

  2. It will be important to keep in mind that now that all of the mega blocking scenarios are showing up all over social media, that a significant blocking pattern does not necessarily translate to more snow in your backyard. Your chance of that may actually be a better if you live in the middle Atlantic states, depending on the evolution of the pattern.

    1. Because too much blocking can cause systems to be
      suppressed to the South.

      We just can’t win around these parts.

      Bring on Spring. Let’s cancel Winter. Why not?

  5. Euro wants to bring the system for 1/4 too close bringing wide spread RAIN to our area.

    https://m3.pivotalweather.com/maps/models/ecmwf_full/2020123000/132/prateptype_cat_ecmwf.us_ne.png

    CMC

    https://m2.pivotalweather.com/maps/models/gdps/2020123000/126/prateptype.us_ne.png

    Kuchera snow

    https://m2.pivotalweather.com/maps/models/gdps/2020123000/144/snku_acc.us_ne.png

    GFS just hasn’t gotten the memo!!

    https://m3.pivotalweather.com/maps/models/gfs/2020123000/126/prateptype_cat.us_ne.png

      1. I was going to post that, but thought it too jaded of me. 🙂

        Clearly the 1/3-1/4 system is getting up here. My only fear is precipitation type, which will likely be RAIN, at least near
        the coast. We shall see.

      1. A Goldilocks solution, eh? That would be nice,

        Would not be blockbuster, but would be nice to add another few inches to the season total.

  18. 12z Euro looking pretty interesting for next Friday 1/8 as well:

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=prateptype_cat_ecmwf&rh=2020123012&fh=222&r=us_ne&dpdt=&mc=

    And with another storm on its heels behind that. Notice the nice cold blocking high that sets up shop over eastern Canada on that run.

    Operational models really starting to pick up on that projected -NAO blocking now and it should set up a return to a more favorable pattern for winter weather as we head into January, after our brief holiday week respite. It is helping too that the block appears to be shifting to be more west based, which should prevent systems from cutting west of us. The current -NAO set up has been pretty much useless to us.

    And yes I realize if the blocking gets too strong , it can result in systems missing to our south but I’d much rather take my chances with a good block in place as opposed to the SE ridge/cutter-palooza set up!

    1. Agreed. But look closely at the 1/8 set up. That becomes
      mostly a miss to the South. Of course, much time to go, but perhaps an early sign that the blocking may, indeed, be a touch too strong. Time will tell.

      1. And, oddly enough, the one sitting behind that 1/8 system
        looks like it wants to CUT West of us. Go Figure!!!!!

        1. No way, not with that high over southern CA. The low is actually heading SE out of Colorado on that loop. If anything it is going to transfer energy to a new low over the Southeast. It actually probably misses us south out to sea on that run.

          1. What is driving the 1/8 system from coming any further north on the Euro then? Appears to hit a block with that high over eastern CA and get shunted east. NAO is progged to be negative by nearly 2 standard deviations at that time as well. Are you saying the block is still more east based in that time frame?

  19. Dawn Wells died this Wednesday morning of complications from Covid-19 at the age of 82. 🙁

    I will also post this on the Covid-19 page.

    1. I loved her. She ran her own FB fan page and kept in touch with all her fans there. Having seen the entire Gilligan’s Island series in reruns several times thanks to my brothers, I was always a fan of the show and of her.

      That leaves only 1 main cast member still alive.

  21. Couple thoughts on the weather this afternoon…

    Tonight / Thursday Morning… No changes, warm front followed by cold front, minor rain event with cold front.
    Thursday Afternoon / New Year’s Eve… Clouds may be stubborn to move out during Thursday PM but it will be dry for any limited travel going on that night.
    New Year’s Day… It should dawn sunny & crisp, my favorite type of New Year’s Morning. I may greet the sunrise at a local pond, or if I feel really ambitions after just a few hours of sleep I may drive to Hampton for it. Clouds roll in later, and we should end the day with a slate grey overcast, the “snow sky”, although this time it’s not leading to a major winter storm…
    Friday night / Saturday… A minor messy storm that is only with us for about 12 hours as the mix then rain, with clearing later Saturday.
    Sunday / Monday… Clouds roll back in quickly Sunday, and after ignoring what is probably over strengthening by some guidance, we end up with a relatively minor precipitation event Sunday night into Monday. It’s a toss up for rain vs. snow, as we’ll have marginal & limited cold air available and may lack precipitation intensity.
    Tuesday-Thursday next week… Rather quiet for a few days, though a minor system may still bring some clouds & a tad bit of precipitation about Wednesday.
    Late next week… Far too early to do much speculating on a possible low pressure impact on Friday January 8, if it happens at all, given the timing & system resolution issues with guidance. So basically anything from January 8 on is unchanged (refer to my summary from this morning’s post).

      1. I’m definitely not too excited about that system right now. A few days to go though… We’ll know more after the Friday/Saturday system exits. Our guidance has been having trouble resolving this into several pieces of energy and may still not be doing “figuring it out”.

  24. Thanks, TK…

    Happy New Year’s Eve Eve, y’all…

    Two weather events I recall from 2020:

    TS Isaias’s arrival early August…
    Rain and wind event September 29-30.

    The latter sticks in my mind because it affected the opening of school that day: extreme wind, sideward, drenching rain, power and Internet outage and the fire alarm went off five minutes before first period.

    Sorry to hear about Dawn Wells. My two all-time favorite Gilligan’s Island episodes involve Mary Ann. The first is when Mary Ann has amnesia and thinks she’s Ginger. The second is when The Mosquitos end up on the island and Mary Ann, Ginger and Lovely form the girlband, The Honeybees.

  26. For the second run in a row, it’s a really nice look on the 12z Euro EPS as we head into mid January. The Pacific becoming much less hostile with -EPO and +PNA ridging out west. This should help drive the colder down into southern Canada and the eastern 2/3 of the US. Coupled with the -NAO blocking we have been talking about, this is a more favorable winter weather pattern in the east.

    Of course two week model projections right now are hardly written in stone so keeping the optimism guarded!

    1. Hints on the GEFS and EPS, as I posted above, that those fortunes on the Pacific side may be changing as the EPO flips negative in a few weeks. Could be more interesting times ahead…

      <> 🙂

  31. You mean Mr. Realist….

    The fact that the first attempt by the GFS (not the atmosphere itself) is a fail should tell you something. 😉

    The Pacific jet: “maybe later in January?” .. that should tell you something too.

    Oh, and about the ensemble MJO forecast…………….
    3, 4, & 5 are not numbers you want to see if you’re a snow lover. 😉

    We’ll see though. There’s a lot to work out.

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