Sunday December 19 2021 Forecast (9:39AM)

49 Comments

DAYS 1-5 (DECEMBER 19-23)

Low pressure moves away today with improving weather after our minor kind-of-winter event. The coldest air of the season-to-date moves in behind this system, but not in a blasting kind of way, but in a quiet way as high pressure settles over the region tonight and sets up radiational cooling with the cold air mass having just arrived. This high will bring us fair but cold weather Monday followed by a slight moderation Tuesday as it moves offshore. A cold front will slip through the region quietly later Tuesday with colder air returning by Wednesday as a storm system evolves offshore. So far it looks like this system will be a miss but we’ll still have to watch it, and also may see some snow showers (except rain or snow showers Cape Cod) from a little trough connecting that system with one to the northwest of our region. The offshore storm moves away and high pressure moves back in Thursday with more fair weather.

TODAY: Mostly cloudy start with a few lingering snow and rain showers. Increasing sunshine follows. Highs 36-43. Wind N to NW 5-15 MPH, higher gusts, diminishing late.

TONIGHT: Clear. Lows 12-19. Wind calm.

MONDAY: Sunny. Highs 28-35. Wind NW 5-15 MPH.

MONDAY NIGHT: Clear. Lows 17-24. Wind W up to 10 MPH.

TUESDAY: Mostly sunny. Highs 36-43. Wind SW 5-15 MPH.

TUESDAY NIGHT: Partly cloudy. Lows 25-32. Wind SW 5-15 MPH shifting to NW.

WEDNESDAY: Mostly cloudy. Chance of snow showers except rain or snow showers Cape Cod. Highs 34-41. Wind N 10-20 MPH.

WEDNESDAY NIGHT: Mostly cloudy. Chance of snow showers early. Lows 23-30. Wind NW 5-15 MPH, higher gusts.

THURSDAY: Mostly sunny. Highs 35-42. Wind NW 5-15 MPH.

DAYS 6-10 (DECEMBER 24-28)

Active pattern with temperatures running near to below normal. Timing disturbances will be impossible this far out but look for two potentials for precipitation during this period.

DAYS 11-15 (DECEMBER 29 – JANUARY 2)

Similar pattern of frequent but not too powerful systems with additional opportunities for some precipitation. Temperatures near to below normal.

49 thoughts on “Sunday December 19 2021 Forecast (9:39AM)”

  2. Thanks TK.

    Logan recorded 0.1” snowfall yesterday bringing the total to date at 0.4” for the season.

    A mainly wet Christmas Day? 🙁

      1. Both Chs. 4, 5 had rain for Christmas Day on their 7-day outlooks with temps in the 40s. Of course I understand that it can change this far out. Hope it does actually.

        2. I honestly wouldn’t waste my time looking at icons for something that’s still about a week away. Either of those stations could show snow, rain, or anything in between, and it wouldn’t mean a thing at this point.

          Refer to something that the meteorologists here constantly remind us all of.

  5. If there is ever a great set of examples to follow about the stuff that we preach regarding the uselessness of guidance beyond a certain period of time, pick a model any model and go back as far as you can and look at each one of their forecast maps for 12 Z December 25. It’s a day that everybody focuses on every year so it’s a great example to use. And I’m honestly not sure how many more examples of this we need. 😉

  12. And it should come as no surprise, that if you take the 06z and 12z GFS verbatim and use it as “the forecast” for Christmas Day, you’d have 2 completely different forecasts. Need I say more? Probably… 😉

    I’ve actually seen this model issue translated on social media as “the weather people can’t make up their minds”. Ummm…… wow.

  13. TK – You mentioned “uselessness of guidance” beyond a certain period of time, but what else do you expect the tv met to do? He/she has to post “something” for the viewing audience. I highly doubt station management will accept a blank screen for that day 7 or 10 or whenever.

    If you were a tv met, would you present 7-10 day forecasts differently, if station management gave you free reign?

    1. Dude, you know me better than that. I was not trashing any TV folks with what I said. OF COURSE they have to put something there. But what I am saying is whether it is rain or snow on a day 7 (for example) forecast is not going to mean much, because we’ll see guidance flip back and forth several times on said system, before it even occurs, IF it occurs.

      If you think that I’d suggest that they leave it blank, then you need to re-evaluate who you think I am.

      If I was a TV met and the station gave me free reign, YOU BET I’D DO IT DIFFERENTLY! Not drastically differently, because the format would likely be similar, but you better believe it would come with very frequent reminders of the uncertainty beyond a certain time frame, and not to pay attention to a single number or icon in a box.

      Here’s an example of how this can go wrong very quickly. Last night, on a Boston station, the met had a rain drop and a snowflake on the icon for Dec 25 and casually mentioned that there may be “some rain or snow on Christmas Day”, which is actually the right way to go about it. The news anchor however, totally disregarding what the met. said, chimes in after and goes (paraphrasing) “Wow, looks like a white Christmas!” … Immediately derails what the met. tried to convey. This IS a problem. Most of the time it’s not the meteorologist’s fault. Most of the time it’s either a news anchor’s fault or someone in the audience having no idea how to interpret it. This is why the meteorologists need to do more hand-holding and explanation.

      I hope that clears it up a bit more.

      1. Thanks TK! Of course I didn’t suggest they literally “leave it blank”. Sorry if you misunderstood my point. 🙂

        1. And as for that news anchor, don’t know where he was coming from…although probably many viewers with that same mindset, unfortunately.

        2. All good! Just wanted you to know that I’m not that harsh. I may be direct at times, but it’s just the message that needs to get across. 🙂

          Thanks again for your contributions here!

  18. So now we have 3 major models in for 12z with kind-of-sort-of-but-not-really the same general idea for December, but none of them had this just 24 hours ago. However do we solve this dilemma? We write it the way I have it written in today’s blog post. 🙂 Problem solved! Updates to come and fine-tune the outlook, as we usually do. 🙂

    Yes, I definitely realize that it’s an advantage to 1) Have a free-form writing delivery instead of a “box” that I have to fill with icons and numbers, and 2) I don’t have to answer to some boss who has no idea how to present weather. I haven’t forgotten that. 😉

    1. Is my memory shot to hell? or wasn’t it a few to several years ago that the 3 major models were in “reasonable” agreement and not the crap fest we see these days? I just don’t remember it being this bad.

      1. There was a time they were more in agreement more often. For a while the GFS & ECMWF would trade top spots while the Canadian lagged. These days, they are all inconsistent and undependable but the Canadian leads the pack slightly.

  19. RE: Long range… you have to bet on the Southeast ridge until it shows some sign of relenting. *Possibly* towards early next month as the PNA possibly relents a bit. But that can has been kicked down the road several times already. The next 10 days in most of SNE probably average on the + side of normal. That is a departure from previous expectations.

      1. I was out walking around sunset as the wind was starting to drop off and I was thinking about how cold it’ll get because of that set-up tonight.

  21. Looks as though it’s getting a little moist around here Wednesday. Models seem to be trending a bit wetter not so much white…

      1. It’s that offshore system that plays a role in setting up enough cold for potential flakes later in the week. 😉

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