Wednesday December 13 2023 Forecast (7:20AM)

90 Comments

DAYS 1-5 (DECEMBER 13-17)

A cold front crosses the region later today with a few snow showers possible in the region, favoring southern NH and northern MA. Otherwise, we stay in a dry pattern into the coming weekend. The coldest day of this stretch will be Thursday, and a moderation will follow. When we get to Sunday, we’ll be watching low pressure down the Atlantic Coast. Guidance is in good agreement that a large low pressure system will get going down there, but the details of its evolution are a little fuzzy still. My early idea is for a system that matures pretty far south and while the primary low sits down there longer, it sends a plume of moisture up the coast and that will be our best chance of getting some rainfall up here. Based on moderate confidence current timing I’d expect this to be late Sunday. (More in the 6-10 day section.)

TODAY: Sunny start, then a sun/cloud mix. A passing snow shower possible this afternoon, especially north of I-90. Highs 36-43. Wind W 5-15 MPH, higher gusts, shifting to NW by late in the day.

TONIGHT: Partly cloudy early with a brief snow shower possible, mainly northern MA and southern NH, then clearing. Lows 21-28. Wind WNW 5-15 MPH, higher gusts.

THURSDAY: Sunny to partly cloudy. Highs 32-39. Wind W 5-15 MPH, higher gusts.

THURSDAY NIGHT: Mostly clear. Lows 15-22. Wind W up to 10 MPH.

FRIDAY: Mostly sunny. Highs 42-49. Wind SW 5-15 MPH.

FRIDAY NIGHT: Mostly clear. Lows 23-30. Wind SW up to 10 MPH.

SATURDAY: Mostly sunny. Highs 44-51. Wind SW 5-15 MPH.

SATURDAY NIGHT: Mostly clear. Lows 27-34. Wind W under 10 MPH.

SUNDAY: Increasing clouds. Chance of rain late-day or night. Highs 45-52. Wind SE 5-15 MPH.

DAYS 6-10 (DECEMBER 18-22)

While there is uncertainty in the eventual evolution of low pressure on the East Coast, and some guidance showing a vastly different scenario, my early meteorological opinion is that the broad low pressure system will be shunted eastward after the initial push of wet weather goes by our area. This would lead to a return to dry and seasonable to mild weather for much of next week. Not a high-confidence forecast, but the leaning at this time, and to be updated as things become more clear.

DAYS 11-15 (DECEMBER 23-27)

Fairly dry, seasonable to mild pattern leading up to about Christmas. Possible unsettled weather late in the period. White Christmas chances are lower than climatology for southeastern New England in the expected pattern, but will watch for any “surprises”.

90 thoughts on “Wednesday December 13 2023 Forecast (7:20AM)”

  2. Thanks TK !

    Liking this weather, no impact to anything that needs to get done.

    Rooting for your take on the next system.

  3. good morning and thank you TK.

    Ocean temp: 48.4

    Last night Pete said big storm brewing
    for Late Subday/Monday.

    Euro, cmc and gfs all want to give us something like 1-3/2-4 inches of RAIN.

    Nam does not go out far enough, but shows the early stages at 84 hours.

    Although this upcoming system will be warm, it reminds me a bit of the super storm in March of 93 it was intense in Georgia and was intense in New England.

    As it is still 4+ days out, it should be interesting to see how it plays out
    Do we get 4 inches of rain, or an inch or so in an initial plume. Time will tell.

  5. Thanks, TK.

    By the way, I do pay close attention to the weather around the globe and have noted some of the anomalies you pointed to in Siberia but also parts of Europe. Though winter has retreated from Northwestern Europe this week, practically all of Russia, including the European side, is very wintry. Record-breaking snows – for December – in Moscow, for example, along with cold temps (though not record cold), and a sustained very chilly start to winter east of Moscow.

    1. https://www.ospo.noaa.gov/data/imagery/arctic/ir/arctic-ir-23347094800.gif

      What you are describing very well, shows up on this OSPO Arctic satellite page.

      Ignoring the gray at the north pole, I think everyone can see the white shade on the other side of the hemisphere over Russia, southward into northern Asia. Tons of frigid air over there. Comparatively, on our side of the hemisphere (right side of the photo), most of the white are clouds, not ground level cold/arctic air.

      1. But this is also why no one should give up on Jan-Feb-March.

        There is plenty of arctic air around now and simply have some of it cross the North Pole and onto our side of the hemisphere and we have an opportunity to be in business.

  7. https://www.pivotalweather.com/model.php?m=gfs&p=500wh_nb&rh=2023121300&fh=126&r=na&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=500wh_nb&rh=2023121300&fh=126&r=na&dpdt=&mc=

    https://www.pivotalweather.com/model.php?m=gdps&p=500wh_nb&rh=2023121300&fh=126&r=na&dpdt=&mc=

    I think the northern jet, up around Hudson Bay ….. Its moved north in these projections.

    Watching that in the models for perhaps solutions that project it being further or much further southeast.

    If it ends up much further southeast, a lot of this next system will get shunted out underneath us.

    1. Of course it all needs to be watched. As I said above, it is still 4+ days out and nothing is etched in Stone. Would it surprise me?
      No. Would it surprise me if we got 4 inches of Rain? NO. Something in between. No surprise there either.

      We’ll just have to wait and see. In the meantime, I am NOT liking what I see.

      BTW, did you check out the GFS FREEZING RAIN scenario?

      https://www.pivotalweather.com/model.php?m=gfs&p=prateptype_cat-imp&rh=2023121306&fh=165&r=us_ne&dpdt=&mc=

  10. Norton NWS discussion re: Upcoming “possible” storm system

    Monday and Tuesday

    The forecast becomes more complex as we get into early next week
    when a series of atmospheric disturbances are forecast to merge
    along the east coast. If we assess the synoptic setup from a PV
    perspective, model guidance is resolving the merger of 3 separate PV
    anomalies that have the potential to produce a strong coastal storm
    for southern New England. Two of these anomalies would originate
    from northern stream energy with one meandering over the southwest
    for most of this week and the second digging south over The Great
    Plains this weekend. Meanwhile, southern-stream energy is forecast
    to produce a third PV anomaly over The Gulf Coast late this weekend.
    As this third anomaly traverses north into the southeastern states,
    we may see the merger of these 3 PV anomalies and a resulting strong
    coastal storm that could impact southern New England Monday into
    Tuesday. While this may be a complex way to describe a coastal low
    pressure system in the forecast, the important thing to note is that
    there are a lot of moving parts that will impact how the forecast
    unfolds. Given the high uncertainty, we`re comfortable with leaning
    on the NBM which places 40 to 60 percent PoPs over the region Monday
    afternoon and Monday night. If we consult ensemble products we find
    that there is a 20 percent chance of 24 hour precipitation exceeding
    2 inches for parts of southern New England between Monday and
    Tuesday morning. Furthermore, there are reasonably high
    probabilities (40 to 50 percent) for 30+ mph winds over The Cape and
    Islands. These are signals that there lies the potential for an
    impactful storm early next week. As confidence increases in the
    coming days, we`ll have more information on what potential impacts
    if any may be in store for the region. Stay tuned for details.

    1. Sounds to me like there is potential, but there are so many
      moving parts, there is also potential of a BUST.

      As I said above, it will be interesting to see how it all
      plays out.

      I could give 2 craps about a bust seeing as how this would ONLY
      be RAIN anyway. Had this been a potential SNOW event,
      I would be MOST concerned about a possible bust. 🙂

    1. Notice the first one would represent the “plume” of initial moisture and the 2nd would show it be shunted Eastward
      just as explained by TK above.


      my early meteorological opinion is that the broad low pressure system will be shunted eastward after the initial push of wet weather goes by our area.

      Most interesting.

    2. That’s what I meant above, when I posted about that northern jet stream.

      If, like shown, on day 6, the cold front is going to be south of us, there’s a projection of high pressure trying to bridge in from the Great Lakes and the low is well east of Hatteras, that’s only happening if the northern jet is a lot further southeast.

      If its screaming through northern New England, this next thing will miss.

      If its over Hudson Bay, like in most of the 00z runs, then a lot of that moisture might be able to get up here.

  15. With the NAO and AO projected to be in such a positive phase, I can kind of buy into the northern jet being displaced really far to the north, allowing for a big chunk of that moisture to get in here.

  16. For what its worth, they have gotten another solid snowfall in Fairbanks, AK.

    I can see it on the Fairbanks, AK webcam.

    They have a very deep snow cover.

  18. 1-5% chance this evolving Gulf system could have some slight tropical characteristics ???????????

    I know it won’t be close to fully tropical, but it might not be 100% mid latitude low either.

  19. A couple of things about the potential system for early next week.

    1. The GFS is in a camp all on its own. The CMC and Euro are fairly similar in that they develop the storm and move it up the coast, with the initial plume of moisture getting here late Sunday night, then the heavy rain on Monday as the storm rapidly develops and passes close to the Cape before heading up into Atlantic Canada. The GFS on the other hand, has the storm get caught underneath an upper-level low and meander around off the Mid-Atlantic coast for 4-5 days, sending many plumes of moisture in. TK and I actually discussed this very early this morning while I was working on my forecasts, and he and I are definitely on the same page.

    2. This system has absolutely zero resemblance to the March, 1993 storm except for the fact that they will both impact eastern North America. This one is on a completely different track, will be nowhere near as strong,, has a completely different upper-level pattern, and won’t have even a tiny fraction of the impact that the 93 storm had.

    3. The bitterly cold air that was in Siberia is no longer there. Temperatures last week were 20-40 degrees below normal (which is extraordinarily impressive). A modified version of it has leaked down into China, where temperatures will be 10-15 degrees below normal in the next few days, but temperatures are getting back to normal in Siberia. This is due to a Stratosphere Warming Event a few weeks ago that was focused on the other side of the pole. That air was NEVER going to come here. In fact, it will have the opposite effect. That much cold over there gets balanced out by above normal temperatures on this side of the pole (look at the anomalies over Canada for the past week). As it moves into China, and then Japan, it will actually help strengthen the jet stream over the Pacific, which will in turn keep a steady stream of Pacific air moving into the West Coast and across the country.

  21. Hi Rainshine. Hope all is well!

    Great discussions and links as always, JPD and Tom. It is great fun to follow this.

  23. Did I miss something ?

    Has anyone on this blog suggested a relationship/similarities btwn the upcoming system and the 1993 Superstorm ?

    1. I did earlier. But I ONLY meant similar in the sense
      that the system remained strong from Georgia to New England.
      How could it possibly be the same with the temperature regime.

      I was only saying that they both were not necessarily fully mature well to our south.

      That is all.

      But hey, anyone can think what they want. I know what i meant. 🙂

    2. I’ve actually seen that comparison in a few places and missed yours.

      If there’s a similarity it’s the strengthening of the low so far south, but the pattern itself is quite different.

      I also am not convinced of stays that strong all the way up. 🙂

    1. No worries. Absolutely understood and with good reason. I’m kind of at that point myself.

      But when you are up to it, please keep Sharing. It is a huge part of what makes this blog great. And I guarantee is always appreciated

    2. The Older I get the more grumpy I get to the point I am grumpy ALL of the time. 🙂 🙂 🙂

      Don’t get old! it sucks!!!

      1. And again…..I’m there with you. But know that your posts bring smiles as well as education/knowledge/tracking fun.

        It’s a trifecta. 😀

  26. Hi, Vicki. We are doing relatively well. Still some dr. appts. ahead. Decorations all up and enjoying many evenings listening to Christmas music with lights out and just the Christmas lights on in the house. Hardest part is getting gifts out. Why? Because I am a terrible gift wrapper! Never was. Well, I guess some people are going to get some strange looking Christmas gifts! Happens every year. I think they see the gift and know it’s from me!

    1. Hahaha. Love it and I’m not great at wrapping either.

      I love to turn off all except Christmas lights and listen to music also. Enjoy ❤️

  27. 12Z EURO has the next system way inside and looks pretty strange to me.

    https://www.pivotalweather.com/model.php?m=ecmwf_full&rh=2023121312&fh=120

    https://www.pivotalweather.com/model.php?m=ecmwf_full&rh=2023121312&fh=126

    https://www.pivotalweather.com/model.php?m=ecmwf_full&rh=2023121312&fh=126

    https://www.pivotalweather.com/model.php?m=ecmwf_full&rh=2023121312&fh=138

    qpf

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=qpf_acc-imp&rh=2023121312&fh=156&r=us_ne&dpdt=&mc=

    10:1 snow

    https://www.pivotalweather.com/model.php?m=ecmwf_full&p=sn10_acc-imp&rh=2023121312&fh=156&r=us_ne&dpdt=&mc=

    1. Re: The upcoming system. I hadn’t seen your mentioning of 1993 previously. A colleague of mine actually brought that up in an email and was talking about the vague similarities and more solid differences between the two systems.

      The similarities are in an area that have a lesser influence in the big picture and many of the details when it comes down to what will happen.

      You noted later that you were referring to the system peaking well south and staying strong. Part 1 I completely agree with. It’s part 2 that gets fuzzy, meteorologically. Superstorm 1993, it first must be reiterated, did take place in a very different synoptic pattern, so in that aspect the comparison shows great differences. What is similar is a large-coverage event, but with a mainly rain event and an all rain event for the major cities we’ll have a huge deviation. Other details of the storm (central pressure, winds, severe thunderstorms FL to Cuba 1993 but not with the upcoming event, will show the differences.

      But I am aware you know all of this and were not referencing such details. 🙂

      One caveat, we’re comparing an event of the past from one that hasn’t taken place yet – we can only go by model projections. This event upcoming can still turn out quite a bit different than what we see modeled, although I do think the guidance has the overall picture there. We still see big differences between the GFS and everything else. To be honest, I’m barely even looking at the GFS again other than just confirming that it’s still forecasting in another dimension while we wait for them to find a way to fix it. And while not perfect by any stretch, the other guidance (GEM / ECMWF) presents something a little more reliable to at least use as a guideline. I keep waiting for something to improve with the GFS but so far – zippo. That’s disappointing.

      Hey Dave, if you don’t have a hat or a cap that says “Cowabunga!” or “#%@!!%!” on it, you need to ask Santa for one. 🙂

      1. Ha ha ha
        Thanks for the nice explanation and I agree 100%.

        I can already see the models changing a bit.

        I just find it most interesting to see how these systems evolve.

        At least I won’t be disappointed in no snow, as it is VERY clear going in that snow is NOT in the equation.

        Still looking way ahead. So far not so good, but there is a long way to go. OF course I haven’t forgotten 2014/2015!!!

        🙂

        1. I don’t want to get anybody’s hopes up, but after the next system goes by, even though I don’t agree with the GFS’s out-to-lunch-overdone blocking, there will be some type of blocking in place to keep low pressure offshore for a few days. This often takes place when we have the polar jet way to the north and you can have a bit of a southward displaced blocking set-up.

          If you line things up right, you get a northerly air flow of chilly (not arctic) air, and some chance that you can drop a disturbance through as it moves toward the offshore low. Once in a while these can fire off an ocean-effect or even synoptic precip event, so it’s not out of the question this happens. Something to watch anyway… I don’t expect it right now, but I also can’t say “won’t happen”.

          1. I actually “thought” I saw that kind of set up down the road, but I simply dismissed it.

            Now I’ll really be watching.

            More likely we’re waiting until the new year. 🙂

    1. This I remember well. Thank you, JJ. Mac’s dad had recently passed and his mom was staying with us. It took him hours to get from Watertown to Framingham. His mom promptly bought him a snowblower after watching as Mac tried to get the one we had (ariens circa 1960ish) started and I had the driveway finished by the time it did start.

      Special memory

  30. Rainshine, I think I am THE worst gift-wrapper in the world, though not quite as bad as my non-existent smart-phone skills (every time I look at the thing I get anxious). So now I just hand gifts to people unwrapped. Less drama or fuss. Certainly no surprises.

    1. My son used to leave them in the shopping bag. He then transitioned to using old newspapers

      Funny thing is that the ones you are both describing might just become a special memory.

  31. Back in November when I was looking at the models and stuff, I was hoping that there would be at least a snow storm or two while I was back, or the very least good conditions to make snow on the mountains. Looks like it could be tough for both. Im in Mass from this Friday to January 10th. Seems the good patterns are just being pushed furtheer and further back.

      1. Yeah I plan too, my Dad and my brother Chris are planning on a ski trip before my brother Ben and Chris go to Iceland in January. They leave a couple days before I head on back down to St. Thomas. I wish I was able to go with them haha.

  32. I find it a bit sad that we’re tracking a RAIN storm on the 18th of DECEMBER and trying to figure out if it might be like the RAIN storm we had on the 10th and 11th of DECEMBER. That just blows. Sorry for the rant.

    1. NWS talked about those. 2 of 3 PV fragment remains that go into the upcoming system. This is coincidental that they are just lined up longitudinally in that particular frame. 🙂

      You can also see a good depiction there of the pretty much uninvolved flow to the north which allows the southern systems to behave a bit more like springtime.

      2. Not to sound totally dumb, but what do they mean by PV in this instance. I used to think of PV as Polar Vortex.

        Many thanks

        1. PV in this instance stands for “potential vorticity”. The actual term is PV anomaly (not really disturbance, but sometimes it’s used instead).

          The short version definition of a PV anomaly is stratospheric air intrusion into the troposphere.

          Now, take that normally dry stratospheric air that now is far more moist than usual, and you have an added factor. Why do you think there was a global temp spike in the last number of months and also some highly anomalous rainfall events? While not 100% proven, the evidence is pretty clear that the HTE putting all that moisture into that layer of our atmosphere is a major player, and I still am puzzled as to why some scientists seem to be ignoring this. You CANNOT DO THAT. You don’t selectively leave things out in science that impact the small picture and the big picture.

          Anyway, before I keep ranting. That’s what a PV anomaly is. And we’re watching 3 interact to form the storm.

          Stratospheric antics and El Nino at work together. That’s also the main reason for the global warmth record currently being set. Pretty straightforward. Does longer term warming play a role? Absolutely yes. But, it’s this shorter term stuff that plays a larger role. I’m nearly convinced of it. We’ll learn more in the months ahead.

          2. THANK YOU! Wonderful explanation.
            I am not even sure I had ever heard the term PV anomaly and If I did, I sure don’t remember it.

            Makes perfect sense now. Thanks again.

  35. TK
    Is this the possible set up you were mentioning earlier?
    No precip shown on this model, but that looks awfully close
    to a decent Ocean effect snow event.

  36. Baffled at the CDC’s messaging on the Covid-19 vaccine. Nearly 3 years after the rollout it still gets it wrong. In the latest message posted this week, it says that we should get vaccinated to “prevent the spread of Covid-19.” That’s inaccurate. A correct message would be: At-risk people and the elderly should get vaccinated to reduce the chance of severe illness and death. https://www.forbes.com/sites/joshuacohen/2023/12/13/three-years-after-covid-19-vaccine-rollout-cdc-still-gets-messaging-wrong/?sh=62a0642c1178

    There’s a reason there’s been a decline in the public trust in the CDC.

    2. The latest booster that just came out the hospital mandated it for all employees period . I got a temporary reprieve until the end of January as I have some testing coming up .

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