Wednesday August 18 2021 Forecast (7:28AM)

122 Comments

DAYS 1-5 (AUGUST 18-22)

Yes, I am aware that some operational runs of a particular model bring Henri as a Category 1 hurricane to a southern New England landfall. But I am also aware that the majority of models’ operational runs and all model ensemble means do not indicate this scenario. My advice: Don’t board the hype train, but pay attention to future forecasts from mets and the NHC. Right now, this is a system that would have its closest pass not before day 5. We have a long way to go. In the mean time, let’s focus on the nearer term. That starts with the arrival of the muggy air today, but with lots of clouds. We won’t see the heat we saw with the high humidity last week, just typical warmth of August as we go through the next few days. Before we have to worry about whatever Henri does (or doesn’t do) to us, we have the remains of Fred coming along to bring us some wet weather. But that isn’t really going to happen until tomorrow, leaving today mostly rain-free with limited shower activity mostly well west and north of Boston. It appears that the track of this system’s remnants, in the form of a weak low pressure area, will be far enough north that here in the WHW forecast area we’ll experience a couple rounds of showers/downpours, with the heaviest rain occurring in areas to our west and north.. Also, expecting a diminished rainfall threat for the end of the week after these remains move away from our region. At this time, I am keeping Sunday’s forecast basically the same as I had yesterday, and we will closely monitor the behavior of Henri, making adjustments in the forecast if needed. Other than focusing on the rough surf that will take place starting this weekend (into early next week), we may not need to change much else. “Stay tuned…”

TODAY: Mostly cloudy. A few showers possible mainly southwestern NH, central MA, and eastern CT. Highs 78-85, coolest South Coast. Dew point middle to upper 60s. Wind S up to 10 MPH.

TONIGHT: Mostly cloudy. Isolated showers. Patchy fog. Lows 65-72. Dew point middle to upper 60s. Wind S up to 10 MPH.

THURSDAY: Mostly cloudy. Scattered to numerous showers. Chance of thunderstorms. Highs 75-82. Dew point upper 60s to lower 70s. Wind S up to 10 MPH.

THURSDAY NIGHT: Cloudy. Scattered showers and possible thunderstorms mainly in the evening. Areas of fog. Lows 67-74. Dew point upper 60s to lower 70s. Wind S up to 10 MPH.

FRIDAY: Partly sunny. Isolated showers and thunderstorms possible. Highs 78-85. Dew point upper 60s to lower 70s. Wind variable up to 10 MPH.

FRIDAY NIGHT: Variably cloudy. Areas of fog. Lows 65-72. Dew point upper 60s. Wind variable under 10 MPH.

SATURDAY: Partly sunny. Highs 75-82, coolest coast. Dew point upper to middle 60s. Wind E up to 10 MPH.

SATURDAY NIGHT: Variably cloudy. Patchy fog. Lows 62-69. Dew point middle to lower 60s. Wind E under 10 MPH.

SUNDAY: Variably cloudy. Chance of showers favoring Cape Cod & Islands. Highs 72-79. Dew point middle to upper 60s. Wind E to NE 5-15 MPH, may be stronger near Cape Cod.

DAYS 6-10 (AUGUST 23-27)

Rainfall threat for August 23 will depend on the track of Henri and an approaching low pressure disturbance and frontal system from the west. Additional showers mostly from the system from the west August 24. Generally drier and seasonably warm weather August 25-27.

DAYS 11-15 (AUGUST 28 – SEPTEMBER 1)

High pressure is expected to dominate, with limited rain chances and fairly warm weather.

122 thoughts on “Wednesday August 18 2021 Forecast (7:28AM)”

    1. 00z GFS too 🙂 🙂 🙂 and the 00z UKMet and the hurricane models continue to trend NW ……….

  9. Thanks, TK.

    And thank you, Matt, for your reply last night about Henri’s waves at Sunset Beach. My SIL will be excited!

  10. New Bedford tides with a full moon occurring Sunday

    Sunday: high: 8:30 am (4.4 ft) 9:00 pm (4.7 ft)
    low: 2:20 am (0.1 ft) 2:00 pm (0.1 ft)

    Monday: similar tide levels, add about 40 mins to each

      1. No impact for Marshfield in a scenario with any center west of the south shore.

        I randomly selected a south coast location, in the case of a south coast storm surge and to show that in New Bedford, for example, there’s an extra 4.5 ft available for storm surge compared to if a surge occurred at high tide.

  11. Thanks TK
    From meteorologist Michael Ventrice

    6zHWRF painting a grim “Sandy left hook” outcome for #Henri , impacting New England early next week. If you live anywhere from NYC-Portland Maine, you should be watching this forecast closely.

  12. Had a nice auto correct typo.

    “Bored” has been changed to “board”.
    Voice wrote the discussion on my phone today. 😉

  15. Jeanetta Jones, TWC OCM 1986-2006, has passed away, a victim of Covid-19.

    She was a great broadcaster in the best days of that network.

        1. Yup, they should have that cone centered to New Bedford on their Sunday night 8pm update. 🙂 🙂 🙂 🙂 🙂 🙂 🙂

    2. Its really a neat evolution at 500 mb of something that tries to close off at 500 mb not too far from New England, while a ridge is building not too far northeast of us and how all that plays out.

  18. From the 11am advisory on Henri.

    NOAA Gulfstream IV missions and special weather balloon soundings have been scheduled, and it is hoped that this additional data will help the models handle the evolving steering pattern.

  19. Its kind of neat to look at the GFS model´s 500 mb representation out to 48 hrs.

    Can almost make out the Greek letter omega, centered in the western Great Lakes.

    Past 48 hrs, that omega flow alters or breaks down a bit, but the right (eastern side) of the omega kind of hangs behind and its whether or not that closes off that kind of effects where Henri goes.

    (I think) 🙂 🙂 🙂

    1. Not good at all ! Also, I think this 500 mb flow would provide amazing outflow on the north and east side of Henri, providing for a very healthy environment for it to thrive in.

      1. And those waters just south of us are warmer than average which would at least slow down any weakening of Henri.

        I am officially worried. Still time, but worried now.

    2. The one helpful outcome, in this projected scenario, is the forward speed would be unusually slow for northeast tropical systems and that might allow enough time over <80F waters to weaken it, though I think that could be offset by the tremendous outflow aloft.

        1. Given how the projected upper flow has been evolving, I´d lean more towards something unusually slow than the traditional hurricane express right up the coast.

    1. Yeah that run is awful for many. The slowness alone causes issues with the rain, wind, tides being long lasting and the high tides astronomically already high.

    1. No idea where that site is getting it’s info, but both Pivotal Weather’s and WeatherModels UKMET maps show a 964mb low passing right over Nantucket and eastern Mass before heading into the Gulf of Maine.

      1. Interesting,

        I got it from this site because they usually have data in well before Pivotal does.

        https://meteocentre.com/numerical-weather-prediction/forecast-systems.php?lang=en

        Just double checked to make sure I had the correct run and I did. Site is usually very reliable, so I don’t know what to say.

        Pivotal

        https://maps2.pivotalweather.com/maps/models/ukmet/2021081800/114/sfcwind_mslp.us_ne.png

        https://maps2.pivotalweather.com/maps/models/ukmet/2021081800/120/sfcwind_mslp.us_ne.png

  29. Thanks TK.

    Grace was a total miss here in the Turks and Caicos and the weather has been great since we got here Sunday. Had a brief shower Monday and today is a bit cloudy but otherwise it’s been perfect.

    Oh how ironic it would be that we avert two active Atlantic hurricanes this week while being on an island in the Caribbean and then come back to CT and immediately get crushed by a Cat 1 like the 12z GFS is showing.

    Needless to say I am watching this intently. Our return flight is scheduled to arrive at BDL at midnight sun night (mon AM). Not good timing…we may be spending the night in Miami if that thing is anywhere close!

    Not going to get worked up yet but as SAK has been saying, New England is overdue.

    1. The Euro initialized it as a 1013mb low. Per NHC, it’s 998mb. If it’s off by 15mb at hour 0, I wouldn’t trust anything it shows.

      For comparison, Initialization pressures by model:

      GFS 999
      CMC 1014
      NAM 1006
      UKMET 1009
      ECMWF 1013

      Based on this, I know which model I’d put more stock in. As the old saying goes: Garbage in, it’s garbage out.

      1. It certainly has lost its king status. But, the upper flow looks consistent with the GFS, etc. Perhaps the initialization is causing it to lose the actual tropical system.

        But, the upper steering that would bring it up here looks not too radically different than the other global models.

  34. If I´m reading Logan´s 5 min ob updates correctly, its 88F there.

    Is it going to hit 90F ?

    HAHAHAHAHAHAHA this would be the best 90F of the season to date.

    2. Thanks SAK !

      Is it my eyes or are the majority of the ones to the left of the mean line having lower pressures and a third to half of the ones to the right of the mean line are weaker scenarios.

  37. Finished watching a most interesting series on HULU called
    MANHATTAN and it was about the Manhattan project where
    the US developed the first nuclear bomb.

    It was loosely based on facts, but it was a dramatization and only a few characters were real.

    They actually developed 2 bombs with different designs.
    One was called “Little Boy” which was a derivative of the original gun type design of “thin man”., which used uranium There was a back up design which was dubbed “fat man” which was an implosion type design which utilized plutonium.

    Little boy was dropped on Hiroshima and Fat Man was dropped on Nagasaki.

    Extremely interesting drama that was very well done.

    Even though it is not totally factual, the drama is well worth a look.

  39. Been tied up today between work and a brief visit to my mom. She continues to do great. Rigorous rehab schedule! Still on track to be home on Sunday.

    Thanks SAK for the trop blog & other info!

  41. I can´t help but notice on the GFS (lets look at hr 96 for instance)

    a projected pressure of Henri of 971 mb and with high pressure retreating to the maritimes, a pressure of 1016 mb in southern Maine.

    That´s a pressure gradient of 45 mb over not the greatest of differences.

    I can´t help but think, should something like the GFS scenario were to verify, that there could be a large extension of the wind-field, especially along east coastal areas near the ocean, extending much further northeast of the center than might usually be seen in a tropical system.

  42. If I´m reading correctly, the NHC has 2 planned recon flights into Henri for tomorrow and 3 scheduled for Friday. Good !!

    1. That’s because there were no websites and thus no place for them to post any graphics. You got the forecast points (3 days only, not 5), and plotted them yourself. I still have a lot of blank tracking charts at home.

  44. Tomorrow is the 30 year anniversary of Bob the last hurricane to make landfall in New England.

  45. From Meteorologist Jake Carstens

    New Hurricane Hunter flight plan is out: Recon for #Henri will get underway late tomorrow morning.
    Upper-level G-IV flights aren’t usually the ones we’re glued to, but they’ll be critical (along with NWS weather balloons) to sampling the trough/ridge pattern steering Henri.

  50. This might be something to consider with Henri.
    Tweet from Dr. Levi Cowan

    #Henri is unfortunately a case where ECMWF guidance is not useful. It does not assimilate synthetic observations of TC intensity, so it thinks Henri is much too weak at 1013 hPa. Models like HWRF, GFS, and COAMPS-TC should perform better here.

      1. Those small numbers on the lines show hours from 00z (8pm I believe).

        So, right now, anywhere between 96 and 120 hrs which I think would be Sunday night 8pm to as late as Monday night 8 pm.

      1. My favorite new number is 120……can we just stick with that and not change it please. But if anyone changes it, can you please just whisper so I don’t hear anything

        1. I think everyone will feel more confident on this come Friday (48 to 60 hrs) out.

          None of these model runs have blasted this thing through New England, so, there can be another option that it makes it towards southern New England and not that it goes out to sea, but that it just doesn´t ever get this far north.

          1. Thank you for talking me off the Cliff…maybe literally since vows are being exchanged at a summit 3,491 feet high. 🙂

  55. Well …… 00z GFS continues the overall theme, I think, that there is upper level flow to bring Henri rather close, relatively speaking, to us.

    May not have strong steering currents once it gets close to us.

    Uncharacteristically slow moving, tropical feature as it is not too far away from New England.

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