Thursday October 21 2021 Forecast (7:33AM)

32 Comments

DAYS 1-5 (OCTOBER 21-25)

A warm front is passing through the region this morning and its parenting low pressure area moving eastward across southern Canada will bring its cold front across the region during early Friday, but both days will be on the mild side, today being the warmer of the two. Our only threat of any rain with either front is a passing shower chance from the cold front Friday morning. Cooler air will filter into the region during the course of the coming weekend, and a low pressure trough in the region Saturday will produce a lot of clouds at times, although any rain threat is limited. Sunday, upper level low pressure will dive across the region out of Canada, bringing the core of the coolest air in. A low pressure wave will be in the vicinity of the Ohio Valley by then and there’s a bit of conflict between various models as to what it does, with some guidance bringing wet weather into southern New England by early Monday while other guidance keeps it to the south with high pressure more in control. I’m leaning toward the latter scenario at this time.

TODAY: Variably cloudy morning, then trending sunnier. Highs 68-75. Wind SW 10-20 MPH.

TONIGHT: Variably cloudy. Chance of rain showers overnight. Lows 52-59. Wind SW 10-20 MPH.

FRIDAY: Partly sunny. Chance of rain showers, in the morning. Highs 66-71. Wind SW shifting to NW 10-20 MPH.

FRIDAY NIGHT: Variably cloudy. Lows 45-52. Wind N 5-15 MPH.

SATURDAY: Variably cloudy. Chance of a few rain showers. Highs 55-62. Wind N 5-15 MPH.

SATURDAY NIGHT: Partly cloudy. Lows 40-47. Wind N 5-15 MPH.

SUNDAY: Variably cloudy. Highs 51-58. Wind N 10-20 MPH.

SUNDAY NIGHT: Variably cloudy. Lows 37-44. Wind N 5-15 MPH.

MONDAY: Partly sunny. Highs 52-59. Wind N 5-15 MPH.

DAYS 6-10 (OCTOBER 26-30)

The trend on guidance has been to evolve a blocking pattern a little more quickly, with high pressure generally centered to the north of the region over southeastern Canada, and approaching low pressure from the west moving more to the southeast to a position south of New England. The big question is if and when rainfall from this system gets into southern New England and if so, how long does it hang around. At this time, the leaning is that it is more likely to happen during the middle and latter portion of this period, but that is not a high confidence outlook, so check updates.

DAYS 11-15 (OCTOBER 31 – NOVEMBER 4)

The weather pattern coming out of October into early November is dependent on the behavior of blocking that evolves in the days before it. Currently, the idea is for the blocking pattern to be in place at the start of the period, then break down back to a more west-to-east flow pattern. There will be at least one threat of rainfall here, but it’s impossible to time when that may be this far in advance, based on the pattern uncertainty.

32 thoughts on “Thursday October 21 2021 Forecast (7:33AM)”

  10. Thanks TK!

    NOAA issued its official winter outlook this morning. I would say you probably won’t find anything surprising. The temperature and precipitation probabilities look like a canonical La Nina, similar to how it looked last winter.

    https://www.noaa.gov/news-release/us-winter-outlook-drier-warmer-south-wetter-north-with-return-of-la-nina

    For me, the jury is still out to a large extent. This isn’t going to be a year where there’s a “smoking gun” you can point to beforehand which gives you decently high confidence on how the winter will play out well in advance. Usually the only time that happens is a strong El Nino.

    The idea of a warmer southern tier (Southeast ridge) and cold/wet Northwest is probably the most likely overall. But we thought that last year, and there were long stretches where it didn’t play out that way, even though the end result for the Northeast was actually similar to what you’d get in that type of pattern. And even in a prevailing Southeast ridge/Northwest trough pattern, the results for SNE can vary considerably.

    Bottom line, if you’re a cold/snow fan in SNE, I would say to keep your expectations reasonable, but I don’t see any cause for despair at the moment…

      1. We are ? 🙂 🙂 🙂 🙂 🙂 🙂 🙂 🙂 🙂 🙂 🙂 🙂 🙂

        I have a strange relationship with winter. On one hand, if we had today´s weather, every day, til next early May, I´d be happy.

        And yet, once the first snow starts falling, I get excited in the moment. But, I´m not hoping it gets cold anytime soon.

    1. JR brought up 2011-12 on air either last week or week before. He wasn’t making an outlook for the upcoming winter or anything like that per se, but he wasn’t just making conversation either…are there some subtle similarities starting off already?

      1. There is no one good analog for this winter. One glaring thing is that none of these years with La-Nina and -PDO are very good matches for the Atlantic SSTS. None of them have the negative anomalies north of Alaska like this year. Also there been some good snow coverage over Siberia but also good amount of Ice build build up in the Arctic. I will also state that the 07-08 winter was also in lined with good rainfall for the west coast after years of drought Patterns like to repeat. 😉 https://imgur.com/a/Xy0NJa5

  12. If I am reading these charts correctly, for SNE we are to except
    warmer than average temperatures and about average precipitation. To me that spells lower than average snowfall.
    How much lower is the big question. It could vary from average to slightly below to Well-below average.

    1. No way we’ll be able to get above average or even just average snowfall with above average temperatures. This is why I’m just not comfortable with the new 49.2” average snowfall for Logan. Frankly given CC, even the former 43.8” is now shaky AFAIC. Frosts are getting pushed later and later into the fall season. Not to mention the trees hardly turning at all.

      1. We have had several winters with above average temperatures and above average snowfall. Just using Dec-Feb data for Lowell, the winters of 2006-07, 2012-13, and 2016-17 all featured above average temperatures and snowfall.

        The new snowfall average is based on the last 30 years of snowfall. Simple math, period. There is nothing arbitrary about it, and no reason for it to be “shaky”.

      2. The new average is accurate. It’s not shaky at all. It’s changed because it’s a more accurate representation of more recent climate. And the stats do indeed show many above normal temperature winters that also had above normal snowfall.

        I’ve mentioned this many times. And SAK’s info shows 3 examples at a location just in recent years alone. Additionally, we’ve had a good number of colder than normal winters with below normal snowfall.

  13. Hey TK! My Kids are asking for a very early look on Halloween weather. Any early thoughts in terms of whether it will be wet or dry? Seems as if temp profiles will be seasonal to perhaps below average? I know it all depends upon the evolution of the blocking pattern you’ve been speaking of. Thanks!

      1. Haha. Halloween is probably the only day of there year I don’t wish for snow. Last year’s 4 inches didn’t make for an easy time building a Haunted House in my backyard.

        1. I agree. Although we didn’t have power for the first three years my oldest grand was aware of Halloween, so he thought it was part of the holiday.

          We do a haunted house in the garage. I’d like to hear ideas re what you do in your yard if you have a minute.

  16. Double-a-rod, the guidance is funny today. Now the GFS says a faster return to a westerly flow after kind-of blocking. I’m not sure they have settled down yet. My current feeling on Halloween is that it will be unsettled, but not necessarily wet. Temperatures, not sure yet.

  17. The length of the “no cold” in the East is a good example of pattern stability, or a pattern that changes very very little over a lengthy period of time. The West has been cold. The East, very mild.

    We were in a similar pattern of stability (very limited adjustment) in February 2015, except that time the East Coast was COLD & extremely snowy.

  18. …..and then right after that the 18z GFS comes out with a different solution. Well, there you go. The models are a suck-tastic display of uselessness right now. Toss ’em all.

  19. Anyone notice the “epic” tropical season kind of fizzled? 😉
    In fact, the entire northern hemisphere has been quiet for a while now. Zero active TC’s over the entire globe for about a week and counting…

    In a different part of the world, northern hemisphere ice & snow cover is ahead of last year at the same time.

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