Thursday September 28 2023 Forecast (7:25AM)

138 Comments

DAYS 1-5 (SEPTEMBER 28 – OCTOBER 2)

High pressure will hang on with fair weather today, but we’ll see another day of filtered sun, first from lingering high altitude wildfire smoke from Canada, then the arrival of additional high clouds in advance of our next round of unsettled weather. As the upper winds turn more southerly tonight into Friday, we’ll see the smoke be pushed away just in time for the clouds to thicken up. Additionally, early this morning and again tonight we’ll see some patches of low clouds and radiation fog from the light wind and radiational cooling. Eventually later Friday, lower clouds will make an appearance from the ocean on an east to northeast wind as the low levels moisten up. The biggest question to answer: How much impact from low pressure to our south? I think an inverted trough helps bring the most pronounced axis of moisture, initially in the form of showery rain, into the Hudson Valley and western New England, mostly to the west of the WHW forecast area, with a lighter and more scattered rainfall pattern to the east as we move through Friday. And then as an upper trough swings into the region it helps organize a surface low to our south, close enough for a more stratiform rain event, but far enough so that the best coverage of this will be from the I-90 belt southward, with the greatest threat for highest rain amounts in the South Coast region. I’m also still optimistic that despite a potentially cloudy and wet (especially to the south) start to Saturday, the low will begin to wheel away significantly enough so that the weather improves markedly from midday on. I still have to refine the details in the forecast after I’m more certain of this, which I will do on tomorrow morning’s update. And this is how September comes to a close, with another bout of unsettled weather. Ironically as October opens, we’ll see high pressure begin to dominate and we enter a stretch of dry and milder weather starting on Sunday and beyond.

TODAY: Areas of low clouds and fog dissipating by mid morning, otherwise smoke-filtered sunshine. Increasing high clouds later in the afternoon. Highs 62-69. Wind N up to 10 MPH shifting to E.

TONIGHT: High-altitude smoke exits as clouds increase. Patchy ground fog. Lows 47-54. Wind E under 10 MPH.

FRIDAY: Mostly cloudy. Rain showers move in from the south during the day, favoring southern and western areas. Highs 60-67. Wind E 5-15 MPH.

FRIDAY NIGHT: Cloudy. Chance of rain, favoring areas near and south of I-90. Patchy fog. Lows 50-57. Wind E-NE up to 10 MPH.

SATURDAY: Cloudy start including a chance of additional rain mainly from the I-90 belt southward, then rain exits and clouds break for sun north to south midday on, but clouds likely linger along the South Coast for longer. Highs 58-65. Wind NE-N 5-15 MPH.

SATURDAY NIGHT: Clear except foggy areas low elevations. Lows 45-52. Wind N under 10 MPH.

SUNDAY: Early fog patches dissipate otherwise sunny. Highs 68-75. Wind variable up to 10 MPH.

SUNDAY NIGHT: Clear except ground fog patches forming. Lows 48-55. Wind variable under 10 MPH.

MONDAY: Sunny. Highs 69-76. Wind W up to 10 MPH.

DAYS 6-10 (OCTOBER 3-7)

Several days of dry weather and above normal temperatures with high pressure dominating the region at the surface and aloft. Late-period approach of frontal system and trough returns the chance of unsettled weather to the region.

DAYS 11-15 (OCTOBER 8-12)

A little trend in the medium range guidance for a little stronger high pressure from the north and an upper trough near or east of the region with low pressure pushed further south than previously depicted. This would be a mostly dry but cooler pattern. A little hesitant to jump on this as a lasting pattern but more as a shot of cool air early in the period followed by a moderation. Will monitor guidance trends.

138 thoughts on “Thursday September 28 2023 Forecast (7:25AM)”

  1. Good morning and thank you TK.
    Euro most robust for Eastern sections while most models concentrate the rain in Western areas.

    Gfs gives NO rain to Eastern sections.
    .Euro and Gfs could not be more different.
    What is going on???
    based on Gfs results last time, I am inclined to believe the Gfs, but that reasoning could be folly???

    1. If it were a potential snow storm and it was between a monster snow and nothing at all, I would totally lose it as well. 🙂
      Since it’s rain and we have had enough, I really don’t care.

      I only care about getting some model consistency one way or the other. This is INSANE!!!!

    2. I like Ryan’s comment.

      And, as Dave Barry would say, “Lady Night Tweets” would be a great name for a rock band. 🙂

      2. I chuckled at Ryan’s too. I do enjoy our local Mets. What more can we ask for….our own amazing WHW and awesome meteorologists

  10. Thanks, TK!

    It’s Homecoming Week here at good, ole MHS.
    The theme is “Beat the Sandwich Blue Knights” for tomorrow night’s big game.

    Based on the Euro for tomorrow night, we’re changing the theme to “Noah and His Ark!”

  12. 12Z HRRR places the axis of Heaviest Rain over central Connecticut. And starts the rain tonight!

    This is getting NUTS!!!

    Maps to come….

    1. In those areas showing 7+ inches of rain, the rain starts at hr 14, which means that amt of rain in 21 hrs, not 3 or 4 days, but 21 hrs

      and off an inverted trof, no less

      If this verifies, I will just add it to the never ending list of weather events at +1.5C

      1. Indeed. Certainly getting interesting. I just wish we would have a little more model consistency. The divergence is other worldly!

  17. For NYC, was it the remnants of Ida that caused flooding ?

    I seem to remember images, videos and stories of below street level residences suddenly flooded out.

    If some of the guidance is correct, I hope the residents of NYC are ready.

  18. 700 mb inflow and max area (light blue) starting to show on NAM

    Major convergence in SSW flow aloft from cutoff low to the west and SE flow aloft around the high to the east and where they meet and converge, watch out !!

  23. Simulated satellite images suggest cold cloud tops/ tall cumulus in big rain areas.

    If this pans out, rain rates could be extreme.

  26. Mark, not positive on your exact area. I tend to think you are east of the worst CT area. JJ. Looks as if you are in a good portion. I don’t know how much rain you have had total the past month or so, JJ

    And May I add that this is truly insane

  28. Rebooted my computer and then did NOT load MicroSoft Edge and MS TEAMS.
    They are such PIGS on resources. Now my computer is running fine. I use Firefox and only use EDGE for work related…

  37. Thanks TK.

    The HRRR is scary with those 6-9″ rain totals in CT but looks overinflated to me and doesn’t seem to have much other model support. NAM is robust too, but further west with the highest totals. JJ’s area in western CT looks to be in a good spot for some heavier totals.

    Vicki – those heavier totals on the HRRR are indeed just west of my area but even that model gives me 3-4″. NAM is more like 1-2″.

  38. Vicki, you asked last night how I mounted the Ambient weather station. It of course, despite the price, did not come with mounting equipment other than some brackets so I did have to buy a mounting post on Amazon. I have it mounted on the back side of my deck:

    https://imgur.com/LUQeRqj

  40. eweather
    @Eweather13

    The HRRR through 8am Saturday is insane (and it’s still raining east). Most of the rain in W CT falls before 8pm tomorrow on this run. Needless to say, this would cause big problems.

    The NAM is similar with the extremely heavy rain…it’s just farther west over the border in NY State.

    This is looking ugly. Big flooding concerns.

    https://x.com/Eweather13/status/1707420494343909576?s=20

  41. NWS NY taking a more modest approach with the forecasted totals but even 3-5″ would be a lot…

    NWS New York NY
    @NWSNewYorkNY
    33m
    Heavy rain w/flash flooding possible late tonight-Sat. 2-3″ of rain is forecast with locally higher 3-5″ possible. This could lead to isolated to scattered flash flooding, but confidence is low as to where exactly the heaviest will fall. #NYwx #NJwx #CTwx

    https://x.com/NWSNewYorkNY/status/1707426125528629425?s=20

  45. Even with the 12Z runs in, I have to say that TK’s forecast looks pretty fine to me. 🙂

    Now, how much will things change before the action begins.
    Seem pretty obvious that the main action will be to our West.
    How much of that leaks Eastward?

  46. Mark…thank you for your post on mounting your weather station. That would work for me as I could bring it closer to where it might get a Wi-Fi signal. Thank you!

  47. An update on my Mom. She had her surgery to remove the cancer and any other suspicious stuff yesterday. All signs of cancer are gone. The oncologist words were that this is the best possible result from chemotherapy they see and there wasn’t much they had to do. She did have the process done but they went through every organ system and she is, as of now clear. There will be one or two more chemo sessions to make sure they capture anything that went rogue, but those scans are also as of now clear.

  52. Unfortunately, Curt Schilling released to the public information which Tim and Stacy Wakefield wanted to remain private. See link below. Nonetheless, what Schilling revealed is apparently true: Tim and Stacy are suffering from cancer. Tim has an aggressive form of brain cancer, while Stacy has pancreatic cancer. My thoughts go out to the Wakefields. I loved seeing Wakefield pitch his knuckleball. https://www.boston.com/sports/boston-red-sox/2023/09/28/tim-wakefield-cancer-news-announcement-red-sox/?p1=hp_primary

    1. Schilling has always been an ASS!!
      Another perfect example of it.

      I feel so sorry for the Wakefield’s. I always like Tim Wakefield.

  55. Flood Watch up for my area of CT which is not a surprise. Western CT NYC area look to be the bullseye. I wish this was snow with this inverted trough setup.

    1. Tighten the gradient up, slide the amounts southwest a bit so that eastern MA is a little lighter, and increase the amounts slightly in the southwestern areas and that’s what I feel this does.

    1. Lol.

      I am thinking 2-3″ possible even in my area. You could very well end up in the 4-5″ range. So hard to pinpoint the heaviest axis of precip in these inverted trough setups.

    1. Maybe another case study for the Hunga Tonga Effect. This is no coincidence IMO.

      Climate change (AGW or natural) is a slower process. The volcano is a sudden large change / impact. If you suddenly have a bunch of events like this clustered in an area, or over several regions, and the #’s are a much higher spike than a longer term trend, then this is a strong case for the volcano being a big, big part of it. What a unique opportunity we have to study this event…

  70. Hunga Tonga Effect or not, this is a weird, repeating pattern. Notice also how it didn’t really show up last weekend or early in the week (certainly not the magnitude of the upcoming event). This has played out MANY times this summer. And while it’s not in the Boston area this time (the heavy rain, that is) it’s unusual to have yet another massive amount of rainfall in the Northeastern U.S. in a period that now stretches back about 110 days during which there have been so many events like this,

  71. If I lived in a flood prone area or an apartment/condo below street level in NYC and nearby areas, I’m not sure I’d go to sleep tonight. Be on the ready to get out of the water starts pouring in.

  74. If the 00z HRRR is very accurate on location of heavy rain, the getting into the city after 5-6am tomorrow will be very difficult.

      1. Reasonable in that it is plausible those totals could actually occur in this setup. The 10-15” totals this model was showing earlier were not realistic.

  77. It should be noted that some of the outrageous rain totals were due to CF issues with some models. Yes, there’s a shot at a plume of significant rain, but some of the insane amounts – nope. That’s a model “blow-up”.

    Feedback from microphone makes the amp squeal.
    Feedback in the model makes the rain simulation blow up.

  78. With some breaks in the mid level clouds, there was a nice sunrise this morning with many of them briefly orange and red.

  79. Next 7-10 hrs seem like crunch time down around the areas we’ve been talking about.

    Certainly a good coverage of moderate to occasionally heavy rain.

    Let’s see if a small area intensifies even more.

  81. Shorter range, high res guidance have been backing off the threat of intense rain to the southwest a little. I still mentioned it in my discussion as a potential, but I don’t think we’re looking at a huge event out that way. And the WHW forecast area should escape any significant flooding issues.

    This is also to be a much shorter-duration event than the previous one.

    I believe NWS is too pessimistic with their exit of wet weather tomorrow. I’ll take “quicker exit” for $500 Ken.

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