Tuesday December 13 2022 Forecast (7:44AM)

66 Comments

DAYS 1-5 (DECEMBER 13-17)

Not making any changes to the ongoing forecast at this point in time. Large scale blocking pattern continues as high pressure sits to our north and northeast. A large low pressure area to our east will do a loop and at its closest pass helps initiate some snow showers, especially across Cape Cod, Wednesday. Low pressure heads for the Great Lakes Thursday, energy elongates, and new low pressure forms off the northern Mid Atlantic Coast Thursday night and Friday. While the exact track of that low is still TBD, it will likely bring a good swath of moisture across our region during this time frame, with odds favoring rain in coastal areas and rain/mix/snow further inland with mix/snow more likely in higher elevations. Still can’t detail it more than that. Will be able to add more detail tomorrow and certainly by Thursday morning’s update. I do expect precipitation to linger into early Saturday from the first part of the system…

TODAY: Mostly sunny. Highs 33-40. Wind NW 5-15 MPH.

TONIGHT: Partly cloudy. Lows 16-23. Wind N 5-15 MPH, higher gusts.

WEDNESDAY: Sun and passing clouds. Possible snow showers near eastern coastal areas especially Cape Cod. Highs 32-39. Wind N 10-20 MPH, higher gusts.

WEDNESDAY NIGHT: Partly cloudy early, then mostly clear. Lows 16-23. Wind N to NW 5-15 MPH.

THURSDAY: Sun followed by clouds. Highs 36-43. Wind N to NE up to 10 MPH.

THURSDAY NIGHT: Thickening clouds. Rain arriving overnight, may start as snow away from the coast. Lows 31-38 evening, may rise overnight. Wind E to SE 10-20 MPH.

FRIDAY: Cloudy with rain likely, but some mix/snow possible interior higher elevations. Highs 38-45 north and west of Boston, 45-52 Boston southeastward. Wind SE 10-20 MPH, higher gusts.

FRIDAY NIGHT: Overcast with rain likely but some mix/snow possible interior areas especially higher elevations. Lows 32-39. Wind E to NE 10-20 MPH, higher gusts.

SATURDAY: Cloudy start with rain except mix/snow possible interior higher elevations, then breaking clouds with a possible rain or snow shower. Highs 39-46 by midday but turning colder during the afternoon. Wind variable becoming N to NW 10-20 MPH, higher gusts.

DAYS 6-10 (DECEMBER 18-22)

Upper level low pressure crosses the region December 18 with a few snow showers possible. Generally dry and chilly weather is expected early to middle of next week then may have to watch a system for a precipitation threat by the end of the period.

DAYS 11-15 (DECEMBER 23-27)

One or two potential disturbances with precipitation chances, otherwise mostly dry with temperatures averaging near to below normal.

66 thoughts on “Tuesday December 13 2022 Forecast (7:44AM)”

  1. Thanks TK.

    And thanks for your explanation yesterday regarding the CPC temperature maps. I am now slowly but surely getting an understanding interpreting them…I think. 🙂

    I suppose I need time still to figure out CPC precipitation outlooks as well.

  2. I am beginning to wonder now if the blocking will be bringing up coastal “huggers” instead of coastals.

  3. Good morning and thank you TK.

    Thank you for posting about the boundary layer with this next system. I was going to post something about that this morning. 🙂

    As it stands now, we haven’t a prayer with this upcoming system.

    and, as it looks so far, the followup systems “look” to behave similarly. We shall see.

  4. Thanks TK !

    I almost don’t need to look at the 00z GFS to know how it went for snow prospects.

    If its posted here in the morning or late the night before, its a good snow run, if its not posted, its bad for snow. 🙂 🙂 🙂 🙂 🙂 🙂 🙂

  8. Initial primary into the northern mid west plus cold high well to the northeast, perhaps over Labrador, floods southeast Canada with relatively mild air. So, little cold air to our north plus a strong east gradient off the ocean. No chance.

    1. Ya think?
      850MB temps stay well below freezing, however within
      20-30 miles of the coast, 925MB temps are above freezing and remain well above freezing all the way to ground level. As you say, NOT A CHANCE!!!!

      1. Indeed it is Philip. It is a celebration of of light for the shortest day of the year which was December 13. I had a bit of a fall yesterday and all is fine but I have to sit more than stand so the meal I planned will be shortened to Plattar which are Swedish pancakes.

  11. Thanks TK.

    12z GFS maintains the theme of a track farther south and east for the Friday system which would likely be good enough for precip to start and end as snow over many interior areas of SNE. In fact, precip stays as all snow in western CT and much of west/central MA. It is similar to the NAM solution in that regard.

    https://www.pivotalweather.com/model.php?m=gfs&p=prateptype_cat&rh=2022121312&fh=72&r=us_ne&dpdt=&mc=

    This could be good for several inches of snow across interior areas if it verifies. Even ends as snow in Boston.

  13. Strong signal continuing on the models for a potential MAJOR east coast storm later next week around 12/22-23.

    12z GGEM would be a historic blizzard for many areas:

    https://www.pivotalweather.com/model.php?m=gdps&p=prateptype&rh=2022121312&fh=240&r=us_ne&dpdt=&mc=

    12z GFS has another inside runner and would be a snow to mix to rain situation:

    https://www.pivotalweather.com/model.php?m=gfs&p=prateptype_cat&rh=2022121312&fh=246&r=us_ne&dpdt=&mc=

    Plenty of time to watch that one but all the cards are on the table next week for a big storm system over the eastern US with a major cold air intrusion and deep trough over the eastern two thirds of the US.

    2. The coastal plain is cooked for Friday, I agree. But I am more optimistic for the interior including my area for at least some snow. We’ll see.

      Next week however has a lot of potential everywhere.

      Don’t even bother looking at the 12z Euro operational run at hour 240 with rains to Hudson Bay. It looks NOTHING like the ensembles (see my post above).

          1. Realistic Dave for a change.
            I don’t see anything promising. I keep looking and hoping for a change but all I see is the same ole same ole.

            1. I’m not sure what you are looking at. We have a huge infusion of cold air coming nationwide, blocking, favorable teleconnections and the long range model ensemble runs support a wintery pattern upcoming.

              Forget the 240-384 hour operational runs….they are worthless!!! 🙂

  20. Thanks, TK.

    The use of the word “ensemble” is interesting.

    I played in an ensemble. It was a small group of musicians, each with a different instrument.

    In meteorology ensemble doesn’t refer to an average among a collection of runs of different models. Correct? Rather, it appears to refer to an average among a collection of runs of the same model.

    1. Runs of the same model, but each member has a different set of initialized data element(s) , varying slightly from the operational values. It’s an interesting concept that tries to smooth out possible initialization errors. Or that is my interpretation of it.

      1. I found this:

        Instead of running just a single forecast, the computer model is run a number of times from slightly different starting conditions. The complete set of forecasts is referred to as the ensemble, and individual forecasts within it as ensemble members.

  21. Looking at the sfc temp projections, I think even the far inland snow projections are too high. Mid 30s early to mid storm falling to 33F for western New England.

    Maybe elevated areas 1,000 ft and up WAY out west might have a chance at a few to several inches …….

    1. If the CMC/Euro solution verifies, I agree. If track is further offshore like the GFS/NAM and you add some more dynamics to this system as it develops off the coast….that is the best chance for a more wintery scenario across interior areas.

  22. I’m not even looking at any details beyond Friday’s system. It’s impossible. Working on the Friday / weekend details now while reviewing stuff.

    Hint: If you want a decent overall idea of the upcoming pattern, loop the EPS.

    1. Both Messi and Julián Álvarez played out of their minds today. A World Cup win on Sunday will be the cherry on top of a GOAT career.

      Tomorrow’s Morocco and France game is an intriguing match-up!

  26. Mark, when did the Islanders land Sebastian Aho ? I thought he played for Carolina. Lots of talent on the Islanders !

      1. Yes, totally different Aho! The Islanders Aho is Swedish and a defenseman. Not related to the Hurricanes Aho although they are both of Finnish descent.

        The Islanders have been playing well for the most part this season. I’ll gladly take the road point they got tonight from the Bruins. Bruins are ridiculous on home ice this year… now 15-0-1 !

    1. Yeah I was surprised when I left the house at 4am seeing the light snow cover that brought out the sanders !

  29. 00z GFS finally gave us a run that has a lot of cold just before Christmas that many Mets have been referencing on twitter.

    Did they switch back to the old GFS ? One can hope.

    1. Nope. Still the same GFS. It gets some things right. The errors are likely specific and related to over-doing (or under-doing) of certain forecasts at varying degrees based on multiple sets of conditions.

      Some of its errors are (relatively) minor and can compare to typical model bias. Some of its errors are outrageous and unacceptable for operational use. I trust now they are working on a fix… I still say the should have gone back to the old version until they had a satisfactory run in parallel for an adequate amount of time.

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