Saturday September 24 2022 Forecast (8:29AM)

69 Comments

Our weather for the first weekend of autumn will be rather nice overall, but we’ll start it with a little bit of wind chill. While the wind did drop off a bit in some areas overnight, the breeze remained in most, and the rising sun is quickly mixing the air so the gusty breeze is occurring in all areas by mid morning, and coming off low temperature in the 40s, we have wind chills down in the 30s. We’d laugh at this in winter, but when you’re under 48 hours after the end of summer, you’re not quite used to this kind of thing yet. I needed a winter hat late last night for a visit to the sea wall for high tide. First time I have used a winter hat in September that I can recall. Our gusty and cool weather will continue today but under lots of bright sun, so if you have outdoor activities sensitive to wind gusts (yard sale, etc.), keep this in mind! A warm front approaching Sunday will send more clouds in, but despite some guidance indicating rainfall before the end of the day, I am not convinced this happens. There will be a lot of dry air in the atmosphere in the wake of the very large Fiona, now a post-tropical powerhouse moving through southeastern Canada. And while that storm did not directly impact our region, the expanse of dry air around / behind it, is quite large. It will take some time to scour this out, but this upcoming system does have some pretty unstable air with it and it will eventually do so, so that clouds do win out by sometime Sunday night, along with scattered showers and even some thunderstorms in the overnight / early morning hours of Monday. A few of these storms may even be rather potent for this time of year. But despite the instability, the broad trough and low pressure area coming in to start off the week is going to pull in a lot of dry air as well, and despite Monday being an unsettled day with the opportunity for showers, there should also be some sunshine. I was a little more pessimistic feeling about the weather going into Tuesday previously, but today I’m a little less so. While still having a trough nearby, it looks like a main frontal boundary will lie to our south, and another trough to our north and while this is a thread-the-needle forecast for day 4 I feel we have the chance to be in between unsettled areas with dry weather here Tuesday, and a weakened version of the same for Wednesday, with dry weather, just a sun/cloud mix. Confidence is not super-high on those 2 days so don’t lock anything in yet.

TODAY: Mostly sunny. Highs 63-70. Wind NW 10-20 MPH, higher gusts.

TONIGHT: Clear. Lows 45-52. Wind NW to W 5-15 MPH.

SUNDAY: Partly sunny. Highs 67-74. Wind W to SW 10-20 MPH, higher gusts possible.

SUNDAY NIGHT: Variably cloudy. Chance of showers, possibly a thunderstorm. Lows 51-58. Wind SW 5-15 MPH.

MONDAY: Variably cloudy including periods of sun. Chance of showers, possibly a thunderstorm. Highs 62-69. Wind S 5-15 MPH.

MONDAY NIGHT: Variably cloudy. Chance of showers. Lows 52-59. Wind S 5-15 MPH.

TUESDAY: Sun/cloud mix. Highs 68-75. Wind WSW 5-15 MPH.

TUESDAY NIGHT: Partly cloudy. Lows 51-58. Wind WSW 5-15 MPH.

WEDNESDAY: Sun/cloud mix. Highs 67-74. Wind W 5-15 MPH.

DAYS 6-10 (SEPTEMBER 29 – OCTOBER 3)

Previously I mentioned a shot of chilly air for the final days of September. I still think we get the cooler air, but because of the orientation of the pattern, the delivery doesn’t blast in here, but rather eases in, so that we get fair weather and cooler air for the last couple days of the month as high pressure builds in from Canada. And then October arrives with uncertainty in the outlook. We’ll be watching Ian, a newly formed tropical storm in the southern Caribbean, which we are pretty sure will become a hurricane and turn to the north impacting western Cuba and threatening an area from the central Gulf of Mexico to the US Southeast, with Florida about mid point in that area. Until we can nail down the track, we won’t really be able to say with any confidence what, if any, its future impact would be on our area. Today’s medium range guidance shows anything from remnant rains from a system that travelled long over land before reaching the Northeast to a stronger version of the storm having crossed Florida and come at least part way up the East Coast. Either of this is possible, but they are not the only possibilities. We could, for example, have a scenario where the remains of the system never get here, turning east and being pushed out to sea but a Canadian high. So there is now “Ian is going to….” with regard to New England impacts down the road. Just know that in the first few days of October we may potentially hear from some form of it – or we may not. Obviously, this part of the forecast will be adjusted accordingly with time.

DAYS 11-15 (OCTOBER 4-8)

If you have a high degree of uncertainty in the period preceding days 11-15, you are not going to have a whole lot more confidence on the 11-15 day period itself, because a lot of what happens hinges on what happens before. What I can say is that we leave the first part of this period open to influences from some form of Ian’s remains, in a slower-moving scenario. I do think the pattern will support one and possibly 2 shots of chilly air from Canada as well. How it all fits together remains to be seen. Stay tuned…

69 thoughts on “Saturday September 24 2022 Forecast (8:29AM)”

  1. This is a repost of a series of reports SAK posted overnight / this morning. These are time-sensitive.

    The first 2 are from about 1:30 a.m., the middle one is from about 4:30, and the last 2 are from about 8:30 this morning.

    ___________________________________________________

    Arisaig, Nova Scotia, in the northeastern part of the province, has sustained winds of 75 mph with a gust as high as 111mph, and 4 inches of rain since yesterday morning.

    https://www.weather.gov/wrh/timeseries?site=F9205&hours=72

    —-

    Beaven Island, just off the south coast of Nova Scotia, has had sustained winds as high as 78 mph, and a gust to 93 mph.

    https://www.weather.gov/wrh/timeseries?site=CWBV&hours=72

    —-

    Buoy 44488 reported a pressure of 933mb as Fiona passed very close by within the past hour.

    https://www.ndbc.noaa.gov/show_plot.php?station=44488&meas=wdpr&uom=E&time_diff=0&time_label=GMT

    —

    St. Paul Island, just north of Cape Breton Island – sustained winds of 76 mph with a gust to 98 mph over the past few hours.

    https://www.weather.gov/wrh/timeseries?site=CWEF&hours=72

    —-

    The appropriately named town of Wreckhouse, Newfoundland has sustained winds of 62 mph with gusts as high as 95 mph.

    https://www.weather.gov/wrh/timeseries?site=CAWR&hours=72

  2. FYI: I bumped up my temp forecast a handful of degrees for Tuesday based on a more southwesterly wind and delay in the arrival of the next cool shot due to the orientation of surface features. A little nit-pick for day 4 (and 5 actually as Wednesday is also influenced by this) but there you have it. 🙂

    1. I wouldn’t count on it. If you can’t use an area guaranteed wind-sheltered, you’ll need to take extra steps to make sure the wind does not hamper the effort.

    2. This was about 8 hours ago at landfall. It’s gotten better there now. Storm is weaker, pressure is up considerably, but the damage is already done.

      If there’s a bright side it’s that it’s not a lasting storm. It’s gone quickly , and they have a period of more tranquil weather immediately tomorrow for initial cleanup, a bit of unsettled weather early in the week, then a long period of fair weather which will aid recovery efforts considerably.

  9. The forward speed of Fiona played a very big role in the wind aspect of this event for Canada. 1) It got the storm there before it had much chance to weaken, while still completing its transition (which as we know expands the wind field anyway). 2) You still have the factor of adding the speed of the storm to the wind (vector addition), which enhances the effect for areas where the wind direction and direction of storm match up.

    I know the movement has slowed somewhat now, but at one point it was well over 40 MPH. That’s a lot to add on for the right flank.

      1. 46 was the highest I saw, but possibly was just over that at some point. Express train and bulldozer combined.

    2. Agree 100% TK. Forward speed is everything when it comes to Northeast hurricanes. Was certainly the case in 1938, among others. The key is getting a strong hurricane moving with that freight train level speed, for exactly the two reasons you discussed.

      On the opposite end of that, look at Henri last year: was moving much too slowly too far north, and basically died on approach.

  10. Just a quick note on Ian. The 8AM forecast track is out and the current version takes the storm across western Cuba and landfall around Tampa Bay. This is close to the last update. IMPORTANT: Never forget the cone. There can be considerable error, which is why they use this. That cone currently spans from the Keys to the middle of the Panhandle. And as previously mentioned, the potential threat area this far in advance reasonably extends beyond this zone as well, because there are too many factors that can still have an impact on where the system eventually ends up.

    A reminder to always watch the trends and don’t focus too hard on the specifics beyond a day or two. We can’t draw any solid conclusions for US impact yet.

    Does Ian impact the US? Likely. Does Ian impact the eastern Gulf Coast? Probably. Does Ian impact Florida directly? Somewhere between possibly and probably, but knowing that if the storm ended up slower than forecast, it technically could end up somewhere west of there. I’ve seen one solution this morning that takes Ian to the western Panhandle, which if that were true would leave Louisiana vulnerable. I’ve seen another, granted in a model not built to handle tropical cyclones well, that takes Ian nowhere near Florida. 😉 Ok I don’t buy that one. But anyway just to give you an idea on the uncertainty once you get beyond a couple days. It’s all a process…

    Remember once upon a time some GFS runs took Fiona right up the East Coast to New England? Ya, no.

    1. At 96 hours, using the Ensembles from the GFS/ECMWF/UKMET/CMC, the range in possible locations from all of the members varies from Belize to the Everglades.

      http://arctic.som.ou.edu/tburg/products/realtime/tropical/ens/AL092022/2022092400/f96.png

      At 192 hours, using the Ensembles from the GFS/ECMWF/UKMET/CMC, the range in possible locations from all of the members varies from the southwestern Gulf of Mexico to off the New England coast.

      http://arctic.som.ou.edu/tburg/products/realtime/tropical/ens/AL092022/2022092400/f192.png

  11. As of 9 a.m. everybody in the WHW forecast area was out of the 40s except Worcester at 49. By 10 a.m. no doubt they have made it beyond 50. HEATWAVE. 😉

    1. It’s not Nuuk. Looking at a Google Map, Nuuk’s airport isn’t right along the water like that one. Nuuk’s only runway is 05/23 – the one in the video was 16/34.

  15. Down to 46 here but we were down into the higher 40s in June. 59 at nearly noon. This is the weather Philip and I recall when school started back in our day. Don’t know about Philip but I sure love it

    FWIW north central South Carolina was in the 40s this morning 😉

    1. Ironically we didn’t have that many in 2017 but it was still a very notable September because there were 4 major hurricanes in the Atlantic Basin: Irma, Jose, Lee, Maria.

      If you’re going to have a wild month, September is the most likely with the peak of the season at September 10.

      1. I saw that in the comments and wondered if Eric had miscounted. But He’s moved only slightly up so decided to let him have his fun 😉

        1. They are right about the 5. 2018-2022. Just missed having 6.

          It’s a little atypical stat though (the first 2 weeks, etc.) .. typically things are done by month or season, but it’s still there to show a point / stat which I do find interesting anyway. 🙂

          We’ve had 6 active Septembers in a row which is pretty impressive, especially after coming off that extremely quiet first half of the season this year. Shows you how things can turn on a dime. Happened in 1961 just like this. Nothing, then a whole bunch.

  17. Thanks TK!

    RE: Ian… I fully expect it to rapidly intensify into a major hurricane in the far northwest Caribbean, likely sooner than the NHC indicates. Will probably continue to struggle today as it deals with structural issues common to fledgling storms in the deep tropics. But once it works those out, off to the races, and will probably get stronger than forecast.

    A possible saving grace for the US: wind shear and dry air may increase significantly over the northern Gulf of Mexico. If Ian slows down, which appears likely, those forces will go to work on it and weaken it quite a bit before landfall. But it certainly bears very close watching and is likely to become a dangerous storm. I think the GFS seems to have the best handle of the global models. It’s been fairly consistent, compared to the Euro which at times had been indicating an unlikely track up the East Coast. So would pay attention to trends in the GFS.

  20. From a friend in Ontario re her family on NS

    “My brother, sister and two nieces, cousins and their families are safe in this hurricane (Pictau area)..My cousin in Cape Breton is also safe although the damage there is catastrophic..She has been told that there may not be power for a week..my dad’s cousin and her husband in NFLD have been evacuated and their home has been lost to the ocean”

    1. My brother is returning from a vacation today. He went to the Carolinas and Georgia, which may be considered a gamble during the peak month of hurricane season. Well, he won that gamble. The other destination they’ve had several times on this vacation: P.E.I. and NS Canada….

      We know storms do damage. We can’t escape it. But I definitely feel for those folks and wish them the best in recovery. Let’s hope there’s no loss of life. At least property can be replaced, even if it takes time. I don’t have much, but I try to donate a bit to relief efforts for these types of things. I’ll look for one.

      On a happier note, I’m helping my mother do some season-change chores today. She’s downstairs with her favorite music station on, singing at the top of her lungs. Still love how she knows all the words to all these songs. 🙂 This station is run by Bob Bittner. I don’t know if he has a web page proper, but he does have this for you Facebook users (it’s actually 4 radio stations – my mom tunes into the one that uses the call letters WJIB these days):
      https://www.facebook.com/TheMemoriesStations/

      This station is essentially run by one person (with a little help).

    1. Tomorrow night. It has my attention, to be honest.
      I’d like to qualify that saying it’s not a super-high chance, and any strong to severe storms will be rather isolated. But all it takes is one to whack somebody significantly, so we’ll be on the look-out.

    1. It most definitely is. 🙂
      Fiona will be gone soon, but certainly not forgotten.
      It’s not official, but I’m pretty certain this will be the last “Fiona”. That name’s going to be retired.

      1. I figured once it hit PR, she would be a shoo-in to be retired. NS is just the “cherry on top”. 😉

        Frankly, I wonder if Fiona was even worse than Katrina.

        1. As far as retiring. PR may have been enough. But either way, it’s a done deal IMO.

          It’s hard to compare the 2 storms that way. Yes they were both powerful hurricanes. Katrina was certainly worse of the two in terms of its impact as a true hurricane still in the tropics or far southern US. Keeping in mind that PR was hit by Fiona, which was not a devastatingly powerful hurricane at that point (by the standards of the biggies), but it was hitting a place that has never really recovered from Maria because of corruption in their political system. So they were left extremely vulnerable. Yes it was a bad storm, but they could have come away in better shape than they did. But I get that you wonder about the two … Fiona is certainly going to be equally if not more remembered for its impact on Canada. It was weaker than Katrina, in a “category” sense, but it was also vastly different in that it was hauling forward speed, transitioning to post-tropical, and hitting in area that suffers fewer direct hits over a long period of time from a storm that powerful, even with all the big winter bombs that go through there.

          I hope that helps you differentiate between the two.

  26. They can probably quit advisories on both Gaston & Hermine now. Neither are really systems anymore. Gaston has no more convection. Done. Hermine inhaled a bunch of dust and choked herself to death. Done.

    ECMWF gets credit for this: A week in advance it had the disturbance coming off Africa immediately developing into a tropical cyclone (Hermine). Nailed. Credit where it’s due.

  27. Big shift up in the 5PM intensity forecast for Ian, basically in line with what I discussed earlier. NHC now forecasting a peak of 130 mph. That may still be too low – the waters it will be traversing can easily support a Category 5 storm, and the environment appears ideal for it – but once you get to that level, the intensity becomes modulated about as much by factors internal to the storm as external ones.

    2. Those waters have been simmering in that pot all summer, virtually undisturbed. You can’t get much more perfect conditions for rapid intensification as long as you don’t have a hostile environment that the storm is moving into, and it won’t be. Cat 4 at least. Cat 5 would be no surprise. We can only hope it slows and weakens before a landfall.

  32. There’s some potentially relatively very good news regarding Ian, which you would not expect to hear given that the hurricane may attain category 4 status or even higher at its peak. The storm may be all the way down to a category 1 before a landfall somewhere on the Gulf Coast, assuming that the NHC track and forecast is relatively in the ballpark.

    A colleague of mine wrote a very long discussion about this which I will share very soon.

    This is where meteorology comes into play big time over somebody just looking at a chart or a model and assuming that a storm is going to stay at maximum until it is hampered by land. There are other forces at work and that always has to be taken into account.

    Anyway this, while not wonderful news since they were still likely be a hurricane striking somewhere, would be very good news that the storm may not be nearly as intense as it might have been.

  33. Write-up from colleague. You won’t see it talked about much in the NHC discussion but the weakening is apparent on their actual forecast (before landfall, significant weakening too).

    Models like GFS and GGEM show this too, although the peak intensity prior to landfall are CAT 4 and CAT 2 on those models, so they differ there.

    NOTE: TUTT stands for Tropical Upper Atmospheric Trough. I learned a lot about these in college.

    Anyway, here it is…

    ___________________________________________________

    Something seems like it is off. Why is Ian is still struggling
    in the past 24 hr despite low shear, high RH, and 30 C
    SSTs? The 03z NHC discussion noted the circulation is
    elongated.

    I looked at WV loop Saturday and it showed a TUTT over
    the eastern Gulf of Mexico with a classic SW axis and
    dropping/pressing SW with time. So the upper levels
    do not look that good ahead of Ian. So I am wondering
    how the global models are handling this, and the reason
    why the UKMET is the weakest of the 4 global models,
    has me wondering if it might be onto something?

    I have been following the 4 primary global models
    (GFS/ECMWF/GGEM/UKMET) for TC Ian. I’ve noticed for
    the past several runs, the UKMET has had hard time
    making Ian a minimal hurricane. The GGEM and the
    ECMWF are showing a strong Cat 2, and the GFS is very
    intense with a strong Cat 4 in the Gulf of Mexico. Runs
    I looked at were from 12 and 18z Saturday.

    The Gulf of Mexico has been plagued by TUTTs all season
    and obviously it has not changed (no “homegrown” TCs at all). There is unusually dry air
    in the Gulf of Mexico, and there is almost a complete lack of
    convection here and in the NW Caribbean! So empirically,
    things are “off” to me, for the lack of a better term. It’s
    been such a bizarre ATLC TC season, nothing would
    surprise me.

    But the above model differences may be moot as to Ian’s
    landfall.

    Something very interesting I am seeing on some of
    the models. Ian gets very intense on the GFS, and NHC
    explicitly forecasts RI w/ a peaking at 120 kt. Given the
    931 mb 24/18z GFS fcst, it could be close to a Cat 5. The track
    is trending farther W with a landfall in the central or eastern FL
    Panhandle. However, the GFS op runs all along have shown
    rapid weakening before landfall from a Cat 4 to a Cat 1 in
    just 36 hr leading up to landfall. The GGEM supports this but
    the weakening is as dramatic since it does not get Ian nearly as
    strong as the GFS.

    The 24/18z GFS shows a 50 mb weakening
    in 36 hr!

    Here is the 25/00z SHIPS output for Ian. Take note of the forecast
    shear and 700-500 mb RH fields:
    https://hurricanes.ral.ucar.edu/realtime/plots/northatlantic/2022/al092022/stext/22092500AL0922_ships.txt

    Look at what happens at 72 hr. A sig rise in shear and 700-500
    RH drops below 70%. By 96 hr the shear is quite strong (S at 36 kt)
    and the RH has fallen below 60%. Yet Ian is still offshore and not
    moving very fast. I don’t care how intense a TC is, 30+ kt of shear
    will impact it severely.

    So the rapid weakening shown the GFS and the GGEM to a lesser
    extent is not coming out of nowhere.

    Look at the 25/03z NHC fcst. 115 kt to 80 kt just 24 hr 96 to 120 hr
    (and Ian is still just offshore at 120 hr)???

    INIT 25/0300Z 14.7N 77.7W 45 KT 50 MPH
    12H 25/1200Z 15.3N 79.3W 55 KT 65 MPH
    24H 26/0000Z 16.6N 81.0W 70 KT 80 MPH
    36H 26/1200Z 18.3N 82.5W 85 KT 100 MPH
    48H 27/0000Z 20.1N 83.7W 100 KT 115 MPH
    60H 27/1200Z 22.0N 84.5W 115 KT 130 MPH…OVER WEST TIP OF CUBA
    72H 28/0000Z 23.9N 84.9W 120 KT 140 MPH…OVER WATER
    96H 29/0000Z 27.2N 84.8W 115 KT 130 MPH
    120H 30/0000Z 29.6N 84.1W 80 KT 90 MPH

    I don’t think I have ever seen a NHC forecast quite like this
    for a TC in the Gulf of Mexico yet to make landfall.

    Now if this was late Oct or Nov, I could see a hurricane weaken
    this fast while still in the Gulf of Mexico, but it is still Sep, and
    the GOMEX is typically primed for intense TCs all the way to
    landfall. There has been so much talk about RI with TC before
    landfall, but there is *nothing* that says that it can’t do the
    opposite, and the fact it does this in Sep would be way out of
    whack for climo.
    ______________________________________________________

    1. Not to mention Gulf temps 85-90F. Wouldn’t want to dip my big toe into that. 😉

      The Ch. 7 met last evening emphasized that temp range for strengthening.

      1. 80+ is needed. If you have 85+ it’s ideal for rapid intensification, but….water temperature is not the only ingredient. How many times have we had disturbances and even already closed lows over 85 degree water and they’ve done “nothing”. Many. 🙂

Comments are closed.