Friday September 15 2023 Forecast (7:08AM)

147 Comments

DAYS 1-5 (SEPTEMBER 15-19)

I had to chuckle a tad when I woke up early this morning to a feel-of-fall chill coming through the window via Canada while at the same time seeing the early sunlight filtered through the canopy of high clouds from a weather system that originated deep in the tropics. After how humid we had been, and how humid we are currently not, it was just a little funny. But weather is often about interaction between things that originate far from each other, and this will be the case for us the next couple days as Lee, during transition from hurricane, to tropical storm, to post-tropical, will make its northward trek just to our east and make a post-tropical landfall Saturday afternoon in western Nova Scotia. We’ll have a generally nice day today under the clouds, which will limit our sun, but maybe set up a nice sunset later before they thicken up tonight. Lee’s impacts will be limited mostly to rough surf along the coast, with north-facing shores most vulnerable to high tide flooding late tonight and midday Saturday. The wind will be the other most noticeable impact, with a fresh northerly breeze on the western fringe of the storm’s circulation. I’m expecting peak wind gusts of 25-35 MPH over interior areas, 35-45 MPH over the coastal plain, but 45-55 MPH along the immediate coast with 55 MPH + wind gusts possible on the tip of Cape Ann and across Cape Cod and Nantucket. As Lee pulls away Saturday afternoon, the winds will begin to diminish. The rainfall impact from Lee’s passage will be rather limited. The rain shield should expand northwestward from offshore, reaching Cape Cod and Nantucket by 10PM or so, Boston area by about 2AM, and out as far as the I-95 and I-495 belts possibly by just before dawn. But the further west you are, the less likely you are to see any rain and if you do the shorter-lived it will likely be. Dry air in place will chomp up the western fringe of the rain area. For rain amounts, expect traces inland, about 0.10 tops near the NH Seacoast and MA North Shore through Boston area, up to 0.50 inch near the Cape Cod Canal, and 1.00 inch or more from Mid Cape eastward. That’s it. And then Lee’s outta here late Saturday with rapid improvement, maybe another nice sunset for parts of the region, a cool Saturday night with dry air reinforce, and a pleasant Sunday with lots of sun, passing clouds, and dry air. Monday’s weather briefly tanks as a low pressure trough swings through the region with showery conditions – timing to be fine-tuned next updates. This should move swiftly enough so we’re right back to fair by Tuesday.

TODAY: Limited sun – lots of high clouds. Highs 66-73. Wind N 5-15 MPH.

TONIGHT: Thickening clouds. Rain arrives southeast to northwest overnight, steadiest Cape Cod and coastal areas. Lows 55-62. Wind N increasing to 10-20 MPH with gusts 25 MPH or higher inland, 15-25 MPH with gusts 35 MPH or higher coastal plain, and 25-35 MPH with gusts 45 MPH or higher immediate coast, strongest gusts Cape Cod and Nantucket as well as tip of Cape Ann.

SATURDAY: Cloudy through midday including rain likely Cape Cod and a chance of rain eastern MA & NH Seacoast, then increasing sun especially western areas during the afternoon and maybe into eastern areas later on. Highs 66-73. Wind in the morning N increasing to 10-20 MPH with gusts 25 MPH or higher inland, 15-25 MPH with gusts 35 MPH or higher coastal plain, and 25-35 MPH with gusts 45 MPH or higher immediate coast, strongest gusts Cape Cod and Nantucket as well as tip of Cape Ann. Wind in the afternoon shifting to NW and diminishing.

SATURDAY NIGHT: Clearing. Lows 51-58. Wind NW 5-15 MPH.

SUNDAY: Mostly sunny. Highs 68-75. Wind NW 5-15 MPH.

SUNDAY NIGHT: Increasing clouds. Lows 50-57. Wind W up to 10 MPH.

MONDAY: Mostly cloudy. Showers likely. Highs 67-74. Wind variable to S 5-15 MPH.

MONDAY NIGHT: Clearing. Lows 50-57. Wind W 5-15 MPH.

TUESDAY: Sun/cloud mix. Highs 65-72. Wind NW 5-15 MPH.

DAYS 6-10 (SEPTEMBER 20-24)

High pressure controls the weather through mid period as we wrap up summer 2023 and welcome autumn with the equinox on September 23. By the end of the period we may be looking to our south at approaching tropical moisture and increased cloudiness and possibly more wet weather.

DAYS 11-15 (SEPTEMBER 25-29)

A wet weather chance may exist early in the period before high pressure re-takes control with a generally dry and mild pattern for late September.

147 thoughts on “Friday September 15 2023 Forecast (7:08AM)”

  7. Thank you TK and believe or not I heard a TV met yesterday use the words “storm surge” in our immediate coastal area.

    Putting that behind us, I am interested in north shore wave heights and rip currents. We have plenty of surfers who will no doubt give it a try at least in Nahant.

        1. That’s cool. That begins to make it REAL!
          You may get into the rain shield, up here we may not even get into it at all.
          Honestly, I don’t expect much here.

  11. Daughter and family in PA on second day of their drive home. They take an inland route. Daughter just sent a photo of the many utility trucks headed north.

  12. The one thing I learned with the models and Lee ….

    They really struggle with track speed

    The models came to realize Lee would be tracking past Bermuda, up the coast, slightly quicker and that resulted in yesterday’s trof having slightly more influence than was thought 2 -3 days ago when we had a couple runs there where it looked like Lee might be 100-150 miles further west.

    1. This particular event is going to be a classic lesson for model watchers and a great reminder of how important meteorology is.

      Folks such as yourself, and Dave, etc, know this already. But the big takeaway should be what goes on our in social media – you’ve heard me say many times – about what leads to hype, sensationalism, and misinformation most importantly. I need not repeat.

      But yes, great lesson / reminder. 🙂

  13. Filtered sun and breezy here. Assuming breezing is not from Lee. Although we do know what Felix said about assuming

    1. The “wiggle” that the ECMWF mis-simulated so badly it took Lee into southwestern New England as a full fledged hurricane.

      In the world of meteorology, that scenario was essentially never on the table with this system.

      But on social media, you’d never have known that. 😉

      2. yup.
        But we had fun with the models just the same.

        I found it absolutely fascinating view the various solutions the models put forth.

        In the end, it was OFF SHORE as many here fully expected.

        fun times at WHW

          1. My sense reading updates from at least a dozen Mets is they were really clear about potential but also that Lee has to be watched till the last. As responsible as it gets.

    2. I swim away! Now to learn to swim first .. 😉

      I think this is a decent representation of how it will unfold.

    3. Dave you had me freaking out for a minute before I clicked your link. I am just starting to get a little less stressed about my 13 inches of rain this week and the two tornado warnings! Sump pump is now going off every 3 mins.

  17. Thanks TK.

    Glad to know that Boston Mayor Wu’s announcement of 4 inches rainfall won’t verify, not even remotely close. I certainly wasn’t buying it but still wondering what source.

    2. She was just reading a script. Sadly though, that script should have been based on meteorology from the right source(s).

  19. Can someone answer a question? I just looked at satellite image and though the storm is generally moving north, why when I look at the center of the storm it seems some clouds are moving west? There must be some logical reason because I don’t want to say the storm is starting to move west.

  22. As of noon it appears messenger works on phone. Can’t test laptop til late afternoon.

    We have a car show ongoing at work and I have an appointment right after.

    Some of the dry air that I spoke of is eating away at the outflow shield from Lee so you will see splotches of bright or sunshine before we get a more general high cloud cover again later.

  25. It will be interesting if dew points rise a bit overnight into tomorrow morning on Lee’s closest pass, hopefully no higher than low 60s. I have had more than enough humidity to last the next ten summers.

    2. You can take my word that it won’t feel like one of those summer nights. But the dew point will go up a little bit.

  26. https://www.cpc.ncep.noaa.gov/products/people/wd52qz/mjo/chi/ewp.gif

    Ok, I know the next Cape Verde system has gotten the attention of the weather world …..

    However, the above conditions related to the MJO and 200 mb conditions suggest looking much closer to the US for the next tropical threat.

    And the GFS dropped hints long range of something closer to home and now the 12z GFS is dropping hints of something trying to evolve off the SE US coast long term.

    Will be interested in watching the next 7-10 days to see if anything starts to show up closer to the US.

  27. I don’t believe this.
    Gov. Healey has announced a STATE OF EMERGENCY
    for tomorrow due to LEE. AND she is activating the National Guard.

    Now ask, FOR WHAT?????????????????????????????????????

    1. Could it be, that, though not expected, I think the State can ask for Federal Assistance or aid if a State of Emergency is designated, but that cannot if they don’t, should there be some unanticipated damages.

    3. I agree now stuff in pembroke is closed tomorrow because of this declaration. Total overblown in my opinion!!!

  28. Just got a condo notice to get plants and furniture off my balcony. (Maybe the National Guard can help me.) I’m near the shore so expecting more in the way of wind. Most wind forecasts here are much like TK’s for 25-35 MPH and gusts to 45.

  32. I do think the ocean will surprise some folks.

    I agree the timing of any surge closer to low tide and N then NW winds can help, but the shear size of the waves likely to come to shore might be enough to cause some surprising flooding.

    2. This is what I am referring to in my outlook above regarding the time period around September 24-25.

      Obviously extreme low confidence applies to something that far out but that is what I’m referencing there…

      It’s been showing up for a while in that time range. And for quite some time now I’ve been watching that on some of the guidance that you just used to get a rough idea. The general pattern around that time supports high pressure near us and low pressure down there.

  37. Well my appointment got changed so all I had to do is flip my to do list backwards. Hahaha!!!

    Regarding things like states of emergency etc.
    Yeah I get it It’s frustrating when it makes it look like it’s overblown and because of a lot of unnecessary media that has already been explained… I don’t need to go back over that…

    But I believe Tom is correct. Things have to be declared at a certain time in order to be ready for money that they might need even if it’s a minor thing….

    The time we live in now with a lot of hype and overcovered stuff has made people over cautious to some degree. And while I agree that great caution is not a bad thing it can also lead to things like this which will make people look at it a certain way and then they will say look they declare the state of emergency and nothing happened and blah blah blah and you know where it goes from there.

    I just really think it comes down to a money problem and the way things are set up is inefficient. Ironically computers might be one of the reasons. That’s very thing that was supposed to make life more simple and less busy has done the opposite. 🙁

    So even though my initial reaction was one thing I’m not going to trash the governor or anybody for declaring what they declared. At this point in time I don’t think they have a choice…. They should, but they don’t.

    1. No politician wants to be caught with their pants down. Decisions are made with re-election in mind. The main determinant is political survival.

    2. I spoke to two folks who say the governor is far from overblowing things. We have some areas in Massachusetts already dealing with issues. And Tom and my youngest are absolutely correct that the SOE must be in place in the event relief of any sort is needed. As far as folks saying after the fact that it wasn’t needed, I have never been a fan of hindsight I told you so’s. And I guarantee those same folks would complain more loudly if relief were needed and not available

      For one, my initial reaction was negative and I apologize for that. I was wrong.

    3. I’m not sure if they should have a choice. To me it makes sense to have something in place rather than scramble to organize. Maybe I’m wrong.

        1. Indeed.
          I would not want to be in the position to make decisions like that. Not the way things are now.

        2. Exactly. But I wonder if you are more damned if you don’t. Heck my guess is we get very little impact in Sutton. But I took a fair amount of precautions. But then I always do.

      2. I definitely get that and I very much agree. The thing that worries me the most is that people tend to see one phrase or warning or declaration and automatically take it one way instead of finding the details. So yes I agree with the principal of having something in place more as a caution but my worry is people’s perception. That is an issue that I still think can be addressed by our leaders and I do think that there are shortcomings there.

        Part of the problem is that there is just so much information out there a lot of people don’t know what to believe and what not to believe. 🙁

        1. I agree. I didn’t hear her announcement; but if she didn’t explain, it would have only taken a minute.

          On the other hand we are in a state of playing to the lowest common denominator. I detest when the tail wags the dog.

          1. I didn’t hear the announcement myself either. Work has prevented me from being in touch with most things this week. And now this weekend is going to do the same thing for a different reason. Haha!

            I’ll try to catch a replay of it later.

  38. A little bit of statistical info…

    The New England tornado count so far this year is 17.

    The record is 21 tornadoes in 2018.

    The 2010-2023 rough average is 10, up from the long-term average of 8. This lines up nicely with the introduction of dual polarization radar at the beginning of the 2010s and our much improved ability to see tornadoes that were previously missed.

  40. Dew point must be creeping back up after an ever so brief respite. I just walked about a mile and the air is far from being dry. Uncomfortable again, despite it being in the 60s. This is what I mean by a sustained period of high humidity for the past 100 days or so. We get breaks for sure but they’re ephemeral.

      1. I bet dew points end up creeping back up into low-mid 60s for a brief time until Lee leaves our latitude.

        I just fear that the next tropical we won’t be as lucky. Lee could very well have plastered much of this area if it wasn’t for the two cold fronts. Mayor Wu would have really had to have held a “bunch” of news conferences.

    2. Do I see a Charlie Hole developing???? 🙂 🙂 : )

      Just responding to the circle beginning to show up, which means the radar is picking up something very light aloft.

  45. At least a good portion of the WHW forecast area will be seeing the first of potentially two really good sunsets in just a matter of moments…

    1. Frankly I was “stunned” that we saw fairly bright sunshine from beginning to end. I was expecting rapid afternoon cloudiness ending as a very ominous gray sky, more typical of an approaching major event (rain or snow).

      We did good in the sunshine department today. Nice photo to end the day TK! 🙂

      1. Usually when there’s a lot of dry air around it eats away at the edges and the dry air is pretty prevalent both surface and aloft.

        Eventually the cloud deck will thicken up overnight into the morning only to thin back out later tomorrow.

        The possible good sunset tomorrow depends on where the clearing line is.

  48. TK – Overnight on Lee’s approach, will barometers all over coastal NE crash like a rock, if you will? I believe it’s closest pass is going to be at least 150 miles away.

  50. https://www.tropicaltidbits.com/recon/recon_AF305-3813A-LEE_timeseries.png

    https://www.tropicaltidbits.com/recon/recon_AF305-3813A-LEE.png

    The red line on the first link ….. low pressure, 980 mb or lower is widespread, and then towards the “center”, there’s pressure under 970 mb. Neat to see the spreading out to a much larger area of low pressure. Also, can see the strongest winds have moved away from the center. I guess this would be showing Lee’s transitioning to extra tropical.

    1. I think there will be a lot of surprised folks down this way tomorrow Tom, a lot of stuff on Facebook tonight is just ridiculous.

      1. You mean by how it wasn’t a big deal ?

        Yes, probably. We see much worse winter storms.

        Eric F said it perfectly, I believe …. We are lucky. 150 miles closer and we’d be about to experience something very different.

        1. The stuff I’ve been reading Tom is folks think there waking up to this big storm that’s going to cause all kinds of big problems & it’s not at all going to happen that way .

            2. I haven’t seen anything from Humarock. Or from a couple of friends on the cape. But that is a limited number. What is happening down there.

              1. TWC was just showing some lives from that area. Nothing much. A breezy evening. Rough surf on the shore. Nothing too bad.

                1. Yep. That is what I’m seeing on the Humarock fB page.

                  I was confusing I meant I hadn’t seen anyone in hum or on cape overreacting

  51. 11PM … Lee is nearly extratropical and the forecast track as been nudged slightly to the east. I maintain my original landfall forecast of between Tusket and Argyle NS but as a NON tropical cyclone, under hurricane strength. Basically, a regular storm.

    I saw a Tweet from Petey B indicating that the observed wind gusts in eastern New England are LOWER than most model projections at this point. His concern was the potential of over-forecasting the wind. I do think most locations will see winds near or a little below the model projections.

    Also keep in mind that vector mathematics says you need to SUBTRACT the forward speed of the storm on the western flank of a northward-moving storm.

      1. That’s the one. Still going to be some pretty strong gusts along the coast though. I do think for the most part it will stay quite manageable, which is a good thing, given how saturated the soil is. Trees are more vulnerable and can go much more easily than they would when there are no leaves on them and/or the ground is frozen.

        1. There was a tree that crashed down onto a street and wires in Dorchester earlier this afternoon. No injuries as far as I know. Hopefully they got their power back by now. Fortunately it wasn’t in my section.

          I assume it was a perfect example of a waterlogged tree combined with gusty winds. Hopefully they will be few and far between for the rest of this weekend.

          1. It was a perfect example. My guess is that the tree was on the older side, but since we still have many of those around, you can see what kind of danger that can present. It doesn’t take much.

            So yeah, we don’t need a big gale & direct hit to have a danger of power outages, or something even worse, from a fallen tree. Hoping for the best.

  52. Model watchers: The 02z HRRR Lee track is so funny to watch. Wobble – wobble – wobble – wobble …

  55. Dewpoints in the upper 40s just outside Boston, and lower 50s right along the coast. That rain won’t penetrate too far inland with that dry air in place, especially with now-extratropical Lee passing about 225 miles east of the Cape.

    Next up, a cold front with an area of low pressure riding along it on Monday, which suddenly looks a lot wetter than it did just a day or two ago.

      1. Ch. 5 had that Monday event on their futurecast with very dark greens and yellows, typical of much of our summer. I also bet Monday will be a lot more humid than it is now.

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