Tuesday September 12 2023 Forecast (7:32AM)

167 Comments

DAYS 1-5 (SEPTEMBER 12-16)

The frontal boundary that was draped over the region yesterday, and a player in what turned out to be two intense rain areas with major flash flooding (Leominster area, North Attleboro area), is washing out in place and what’s left of it will drift offshore today. A nearly indiscernible bubble of high pressure will be just enough to help clouds break for partial sun today, but any sun will help fuel a few pop up showers and a very low risk of a thunderstorm. The good news is today’s activity would not organize into quasi-stationary lines and dump a ton of rain, but would just be smaller single cells or small clusters that would pass by, albeit a bit slowly. We still have a very weak steering flow in this humid atmosphere. But things will change soon. The bad news is to get that change to take place, part of it involves another shower/thunderstorm opportunity Wednesday, mainly afternoon and nighttime, as a cold front moves into the region from the west. This front isn’t an express train by any means, but it is going to moving along at least, just taking its time, so the shower threat persists into the early hours of Thursday before dry air arrives from west to east. This sets up a very nice Thursday afternoon through Friday with a well-deserved break in humid, wet weather. Friday is easily to be the weather pick of the week. Late Friday and Saturday our attention will be on Hurricane Lee as it makes its closest pass to our region. My expectation at the moment hasn’t changed much from my earlier ideas. Yes, we need to watch the storm. It’s going to send at least big waves and heavy surf into our coastal areas. It’ll probably invade eastern portions of the region, at least, with its cloud canopy. For the moment, I think the track of the accelerating / expanding / transitioning storm will be off shore enough that its rain shield will stay over water, making its closest pass during the first half of the day Saturday. If this idea is correct, we’d have a day with clouds overhead, but dry weather, and a gusty breeze on the back side of the passing storm, which will probably be a low end category 1 hurricane or strong tropical storm, in the process of transitioning from tropical to post-tropical. Lee will have been weakened by additional wind shear and a wake cool pool of water left behind by 2 recent hurricanes off the US East Coast.

TODAY: Patchy fog/drizzle early. Lots of clouds, partial sun, and isolated afternoon showers with a slight chance of thunder. Highs 73-80, warmest inland areas. DP upper 60s. Wind variable up to 10 MPH.

TONIGHT: Mostly cloudy. Isolated showers. Patchy fog. Lows 61-68. DP near 60. Wind SE under 10 MPH.

WEDNESDAY: Mostly cloudy. Showers likely and a chance of thunderstorms midday on. Highs 71-78. DP 60s. Wind S 5-15 MPH.

WEDNESDAY NIGHT: Cloudy. Showers continue. Areas of fog. Lows 61-68. DP 60+. Wind SW up to 10 MPH.

THURSDAY: Mostly cloudy early with showers lingering in eastern MA and NH Seacoast regions, then a sun/cloud mix. Highs 70-77. DP falling 60s to 50s. Wind W 5-15 MPH.

THURSDAY NIGHT: Clearing. Lows 55-62. DP ~ 50. Wind WNW 5-15 MPH.

FRIDAY: Sun and passing clouds. Highs 68-75. DP ~ 50. Wind NW 5-15 MPH.

FRIDAY NIGHT: Increasing clouds. Lows 53-60. DP ~ 50. Wind N 5-15 MPH.

SATURDAY: Lots of clouds / some sun. Highs 66-73. DP lower 50s. Wind N 5-15 MPH except 15-25 MPH Cape Cod with higher gusts possible.

DAYS 6-10 (SEPTEMBER 17-21)

A fair weather end to the weekend on September 17. Next trough brings a chance of wet weather early next week but is expected to be progressive, with a drying trend into and through the midweek period. Temperatures somewhat variable, but not that far from normal.

DAYS 11-15 (SEPTEMBER 22-26)

Looking for a generally zonal flow pattern, a little warmer than average but a cooler interlude or two. A little more confident we’ve lost the wet pattern at this point and are in a fairly quiet one.

167 thoughts on “Tuesday September 12 2023 Forecast (7:32AM)”

  1. Thanks TK !

    I think if the EURO and the few hurricane models come into agreement with a faster track speed, they will shift east to everything else.

    There’s definitely a correlation on the few western solutions between slower trek northwards and heading more west.

    1. That’s probably drizzle and a result of very low level moisture. Since the weather app is probably looking at the radar as part of its determination and the drizzle is not showing up on radar, that would factor in its computerized decision. Another reason I’m not a fan. Nothing will ever be real observation and real meteorology.

  9. Quick rant on Aaron Rodgers situation. So many people in my Twitter feed (which ironically is made up of a lot of public health folks!) out there mocking Rodgers, some of it is hate-filled.

    What’s wrong with humanity? Seriously. You don’t even have to be religious to build compassion and empathy into your life. But surely religion itself tells us not to behave the way people are towards another human being.

    I feel terribly for Rodgers. I don’t know what the status of his injury is, but it’s not looking good. I’m not a fan of AR’s. But he’s a professional athlete and an extremely good one. Football has been his life for nearly 20 years. I wish him well.

  11. Thanks TK. What a 72 hours it’s been with over 10 inches of rain in 3 days. Over 6 of that yesterday. Many basements are flooded, some roads washed out. Shelter open at the middle school. At one point last night we had a shelter in place order. I am hoping to never see that much rain again in that short amount of time from a non-tropical system. Like you said about the perfect convergence, you could see it on the radar clearly. One flowing in from the southeast and one flowing in from the southwest and we were right where they collided. Of course when it started shrinking down last night, we were the last to see, in our area, the torrential downpours stop from that. Fortunately the disturbance showers dried up before reaching us coming in from the west.

      1. Thank you both. My water in the basement wasn’t as bad as others. I feel for those that had feet of water or other damage.

  13. Libya situation from Storm Daniel is critical. As many as 10,000 may be dead from dams that collapsed.

    Moroccan deaths from the earthquake are now over 2,900. The government fears this may climb over 3,000 soon.

  14. Thanks, TK!

    Prayers for the poor souls in the world situations.

    North, how’s your home and property? I had the North Attleboro scanner on and they were calling in mutual aid from Attleboro and Mansfield and other locales.

    1. Hi Captain, We are ok this morning. Pump is continuously on. At one point I had water coming in from a hole in the wall where the water line to the house comes in but my neighbor and I were able to fix the that, as it was due to the pump evacuation pipe pooling up near the house. As soon as we fixed it that stopped but it was like a faucet for a little while the way it was coming in. The water is receding that was coming up from the floors in other areas but no damage as all of it is happening in my unfinished part and was mostly away from the stuff we have stored down there. A wet/dry vac is great to have. If folks don’t have one, get the self emptying one to have on hand. It is a lifesaver in those situations. Hoping to get some sleep tonight.

      My neighbors both ended up with water too and one of them had their pump stop working in the night and has much more water than last night this morning. We were over there helping before that happened.

    1. Thank you, JJ. I was in sixth grade and we got to miss school. I set up my homemade weather station on a back semi enclosed porch and spent the day following everything

  22. I was out doing a few errands this morning here in Lunenburg. I didn’t see any serious problems. Our sump pump is able to keep up,

    The area in Leominster that Ch 7 reported from last night is just over four miles from our house. The difference in conditions was shocking.

    1. So glad you are all right and your sump pump kept up. I’m listening to north Attleboro scanner now and they are still pretty straight out. In addition to the residents, these folks have to be beyond exhausted.

  23. My friend is Leominster is safe, but “stranded” until some roads are cleared. She’s ok for several days.

    The mayor of Leominster is a great leader. They’re in good hands.

    2. Local sports radio talk hosts this morning are all giddy as now the Patriots “should” have two automatic wins against the Jets.

  33. Regarding Aaron Rodgers, as I said above I detest schadenfreude. I am certainly not giddy about Rodgers’ injury. And I concur with Tom, the Jets’ defense is on another level. So we shall see about whether it’s easy to beat them.

    While I don’t like Rodgers personally, I feel badly for him. Football has been his passion for more than two decades. He’s very good at his craft, too. He’s also a very smart person. Enigmatic, sure. Even a bit peculiar. I strongly disagree with him politically. But you know what, eccentricity and stubbornness aren’t terrible flaws. And as far as his politics is concerned, I don’t give a darn because it is ultimately his choice and right to choose. And having the ability to speak freely about our choices and to choose accordingly is a wonderfully American quality.

  34. This year, so far (and it’s only September 12th), the U.S. has already been hit with $23 billion in bills to respond to natural disasters this year — the highest number on record.

    The natural disasters have thus far killed at least 250 people and caused more than $57 billion in damage, which has brought the federal disaster fund down to just over $3 billion. The Biden Administration has asked Congress for another $16 billion to boost the fund, which otherwise could go into the red by the middle of September.

      1. Was trying to show the difference side my side. If you click on 00z and 12z for the 12th. It shows the two compared in loop. Pretty cool.

    2. I do believe that the model you mention is, indeed, specifically designed for hurricanes. It is listed under the hurricane
      models at Tropical Tidbits. I know it also lists the EUro, GFS and cmc as they are global models and DO handle hurricanes as well, but the HAFS-A and HAFS-B are designed for hurricanes.

      Hurricane Analysis and Forecast System HAFS provides more reliable and skillful guidance on tropical cyclone track, intensity, and structure, including rapid intensity changes, genesis, and storm size; including the ability to extend forecasting out to 7 days.

  41. My messenger is still O.O.C. Grrrrrrrrrrrrrrr!!!!

    Short break between two shifts. Gotta get back to work for several more hours. Good day all!

  42. SREF not indicating any tornado risk for SNE tomorrow even though SPC has the marginal area in a 2% tornado chance.

    1. Neither the 18z HRRR nor the 12z 3km NAM impress me about tomorrow. The 18z NAM is just coming in…

  45. The official Lunenburg total for yesterday is significantly more than what I got from a local personal weather station:

    …Worcester County…
    Leominster 9.50 in 1006 PM 09/11
    Lunenburg 7.26 in 0955 PM 09/11

  46. At 9pm ish, I’ll post the updated hurricane models.

    https://www.tropicaltidbits.com/storminfo/13L_tracks_18z.png

    Based on what I’m seeing, the new round of the hurricane models are west. HMON, maybe 15-20 miles and out by southwest more Nova Scotia.

    HWRF looks a good 1.25 degrees west and the other models maybe 30-50 miles west.

    The HAF B which was the extreme western outlier might be slightly east.

    I think we’ll see a difference visually. Most still out at around 67-68W longitude, but not quite 65-66W latitude 6 hrs ago.

      1. Thank you. I was going to ask. A friend on coastal Maine is wondering. And I’m wondering if there is any concern this far inland

        1. Hi Vicki and Captain.

          Well, when you get a western outlier run, there are some big numbers. 50+ gusts along the immediate coast.

          My first guess if this thing tracks 200 miles east of us would be quite gusty along the immediate coast and breezy inland.

          If it’s 300-400 miles east, probably breezy on the Cape and some high cloudiness.

          If something unexpected happens and it comes really close, then, kind of a very very, strong northeaster.

          1. Sure,

            I’m not sure I answered your question above. Verbatim, the models put out some numbers on the western outliers that I don’t really believe are realistic.

            So, that’s why I didn’t use numbers. 🙂

  48. https://www.pivotalweather.com/model.php?m=ecmwf_full&p=500wh&rh=2023091212&fh=96

    Yes, this is one of the western outliers, the euro.

    What I think is starting to happen is, the models are picking up on a strong, potentially cutoff low north of the Great Lakes. East of it, in response, the jet stream really lifts north into Quebec province and New England is left in rather light steering currents, which allows the hurricane and some quirky 500 mb extension to wobble closer.

  52. The 18z euro ensemble members are west.

    I’d guesstimate about 60-70% of its ensemble members track Lee within 150 miles or closer of eastern Mass.

    Again though, it’s been the western outlier.

    1. That’s the Euro loop 🙂

      Can see the transition from tropical to extra tropical on approach to us (tall thunderstorm clouds disappear) and can see that nw tug back towards the northeast.

      Pretty cool.

  60. The gfs op run has a slightly slower northward track, but it’s a good bit further west.

    Let’s see next 18 hrs – 24 hrs on run

  62. https://www.pivotalweather.com/model.php?m=gfs&p=500wh&rh=2023091300&fh=81&r=conus&dpdt=&mc=

    2 new problems I believe ….

    1) Lee moved slow today and I believe it doesn’t get as far north as the models thought even 12 hrs ago so it’s influenced a little less by tomorrows trof

    Then …..

    2) quickly switch to an amplified pattern in southern Canada with a small closed low north of the northwestern part of the Great Lakes. This builds a ridge quickly north of us, possibly offering a little blocking to approaching Lee.

    Well, I still think more adjustments are coming.

    Im so glad though that if we get a big hit, the models will have given us a lot of prep time.

    My goodness, it’s Wednesday and we’re talking about Saturday.

      1. It did, but I think the real problems start with a run when the model initializes the pressure way too low, like a recent euro op run did, when it had 915 mb or something like that. 🙂

  64. And Lee is massive already in its wind field per a tweet by Michael Lowry that Eric F reposted.

    Well, tomorrow should be fun seeing more Lee developments and hoping no one zone gets training thunderstorms.

  65. One more observation.

    The pressure stays the same 961 mb from mid Atlantic to ESE of Nantucket.

    Yes, the tropical part of the system is likely weakening during this trek, from cooler water and shear.

    But the pressure is not dropping, because the storm is getting some energy from the mid latitude jet stream as its transitions from a tropical system to a mid latitude system. Very intense storm all the way to our latitude, arriving with different characteristics than a tropical system.

  66. The 00z GFS is garbage. It initialized the storm about 17mb too weak. When your initial error is that large, it means that the model won’t handle it the storm properly. Toss it.

  68. 0Z HAFS-B

    https://www.tropicaltidbits.com/analysis/models/?model=hafsb&region=13L&pkg=ref&runtime=2023091300&fh=84

    https://www.tropicaltidbits.com/analysis/models/?model=hafsb&region=13L&pkg=ref&runtime=2023091300&fh=84

    https://www.tropicaltidbits.com/analysis/models/?model=hafsb&region=13L&pkg=ref&runtime=2023091300&fh=84

    https://www.tropicaltidbits.com/analysis/models/?model=hafsb&region=13L&pkg=ref&runtime=2023091300&fh=84

    https://www.tropicaltidbits.com/analysis/models/?model=hafsb&region=13L&pkg=ref&runtime=2023091300&fh=84

    This model rocks Eastern SNE. Crap load of rain, like we really need it.

    This sure looks like it wants to come closer. Of course the above is the closest of all the hurricane models, the others
    are a little more East, but still close enough for impact.

    The Euro has already been mentioned above.

    The Icon has come West as has the CMC, however, the GFS drifted a bit East with the 6Z run.

    6Z hurricane models coming out now.

    Here is one last clue, the slow to react to change NHS has
    moved the cone a little more West with latest discussion.

    https://www.nhc.noaa.gov/refresh/graphics_at3+shtml/085509.shtml?cone#contents

    Today’s runs should be most telling. What a ride this has been already and we’re still 3- 3 1/2 days out.

    1. Wow! my day is starting out great. Some how all of my links are the same. Oh well, just pick one and advance it one frame at a time and you will see the progression and impact of this run. 🙂

  69. Full disclose….
    6Z HAFS-B so far is coming in farther North and East than
    at the same time with the 0Z run.

    I would think that this would translate to a more off shore solution. Pretty big change in 6 hours.

    We shall see what the final run looks like, but it may mean
    the WIPERS are off to the right again.

    1. That would be good news. We really don’t need the rain or winds that would come with it with the ground soaked roots of the trees and high water table in most places.

        1. I never ride the wipers. I stay away from them. Spare enough detail until it’s more certain and you can’t go wrong, unless, of course, you’re wrong. 😉

  72. New weather post…

    Update on messenger issue for FB friends: Still not working. Probably won’t be able to attend to it until Friday, unless it clears itself up randomly.

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