Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
That looks scary, but I don't trust the GFS as much as some other models.
Yeah I still trust most what The Weather Channel reports, though a lot of posters over at Weather Underground seem to know their stuff. Unfortunately Drudge links to them so then the riff raff shows up, the types that know nothing but know it’s all a conspiracy and media hype to push global warming or something. LOL.
 
Last edited:
This could be a double whammy storm. It can strike Florida as a Cat 4, then go back over the warm waters and strengthen again before slamming into the Carolinas. Something similar happened a couple years ago if I remember correctly (hurricane Matthew?)
[doublepost=1567185742][/doublepost]
That looks scary, but I don't trust the GFS as much as some other models.
Even if you look at the Euro, which has a better track record, it shows a similar situation.

70C4ADA2-383D-4758-B130-836314E57382.gif
 
Found this on a Weather Underground comments section. Don’t know if it’s legit or not. But nobody is disputing it. God I hope it’s wrong.

1e4506e52249d712ae75c2ef31f71a8983ef5d0c902ccde3fa4251d1ebdb96b4.gif


EDIT: just saw this posted too. Yikes!
daf0f660356c2a77e00f06b96233dc3c0242015664d6a5cd8eb46bdac0743383.png
While the exact details of the track are still uncertain, it does seem pretty likely at this point that the general idea is…that. It is important to note that Dorian will likely weaken to a tropical storm within a couple of days after landfall (or its closest approach to it), but as you show in the second plot, it will still dump tremendous amounts of rain. Flooding will be a very major concern, especially for coastal areas.

As for the GFS itself… I’d proceed with caution on its solution particularly for precipitation amounts. The general idea is right, but I see that the GFS puts the bulk of Dorian’s precipitation in the left-front quadrant as it moves along the East Coast, which isn’t impossible but seems a bit off given the typical behavior of post-landfall tropical cyclones. Therefore, the precipitation amounts over land are likely at least somewhat overblown, not that it matters much when you’re arguing which side of 1 foot it’ll be on. Flooding will be the largest concern by far as Dorian moves northward — its winds will be far weaker once it begins persistently interacting with land.
 
This could be a double whammy storm. It can strike Florida as a Cat 4, then go back over the warm waters and strengthen again before slamming into the Carolinas. Something similar happened a couple years ago if I remember correctly (hurricane Matthew?)
[doublepost=1567185742][/doublepost]
Even if you look at the Euro, which has a better track record, it shows a similar situation.

View attachment 855387
This was Matthew’s track:
2560px-Matthew_2016_track.png

[doublepost=1567186296][/doublepost]
While the exact details of the track are still uncertain, it does seem pretty likely at this point that the general idea is…that. It is important to note that Dorian will likely weaken to a tropical storm within a couple of days after landfall (or its closest approach to it), but as you show in the second plot, it will still dump tremendous amounts of rain. Flooding will be a very major concern, especially for coastal areas.

As for the GFS itself… I’d proceed with caution on its solution particularly for precipitation amounts. The general idea is right, but I see that the GFS puts the bulk of Dorian’s precipitation in the left-front quadrant as it moves along the East Coast, which isn’t impossible but seems a bit off given the typical behavior of post-landfall tropical cyclones. Therefore, the precipitation amounts over land are likely at least somewhat overblown, not that it matters much when you’re arguing which side of 1 foot it’ll be on. Flooding will be the largest concern by far as Dorian moves northward — its winds will be far weaker once it begins persistently interacting with land.

Do you think it’s possible for a double landfall - hitting Florida, then going back out to sea, then hitting the Carolinas?
 
Do you think it’s possible for a double landfall - hitting Florida, then going back out to sea, then hitting the Carolinas?
It’s possible, but I’d say that if that does manage to happen, it doesn’t present any serious concern of (significant?) restrengthening. Water in that area will be somewhat cooler from Dorian’s precipitation, and it’s unlikely that the storm makes it far away enough from land such that it can be completely free of those effects as well.
 
  • Like
Reactions: hulugu and Rogifan
That's my point, prior to satellites, people had almost no warning and the only indication something large was about to happen was a falling barometer
There were some ways to fill in the gaps before the satellite era, particularly ship reports and collaboration between different countries’ meteorological institutions, that were used to provide some warning whenever possible. Of course, we’re still far better off now.
 
So one model run (Euro) has it moving more eastward and now I see people saying ‘phew Florida dogged a bullet’. It’s way to early to say and dangerous. People need to prepare for the worst and hope for the best.
 
It’s possible, but I’d say that if that does manage to happen, it doesn’t present any serious concern of (significant?) restrengthening. Water in that area will be somewhat cooler from Dorian’s precipitation, and it’s unlikely that the storm makes it far away enough from land such that it can be completely free of those effects as well.
I see some are comparing this to Matthew. But Matthew was about a month later where the waters weren’t as warm.
 
So one model run (Euro) has it moving more eastward and now I see people saying ‘phew Florida dogged a bullet’. It’s way to early to say and dangerous. People need to prepare for the worst and hope for the best.
Yep, the 12Z ECMWF ensemble members show some fresh uncertainty in whether Dorian will make a close approach to Florida or stay well out to sea. Conversely, the 12Z GEFS ensemble seemingly has every single member suggesting that Dorian will make landfall on Florida’s Atlantic coast, an approach which is backed up by the deterministic GFS (FV3). As of now, I’d suggest that there’s a better chance that Dorian will make landfall in Florida than that it won’t, but either way, Florida’s Atlantic coast will see significant impacts from both wind and water. Further north, the hazard will shift to be almost solely water.

I see some are comparing this to Matthew. But Matthew was about a month later where the waters weren’t as warm.
I never, ever compare one tropical cyclone to another and encourage my peers never to do so as well. No two are alike and attempting to compare them is lazy — if not dangerous — when lives are on the line.
 
  • Like
Reactions: Rogifan
Just a mess now, the track could go into Florida, could miss and hug the coast, could cross Florida and reemerge on the gulf. Possible go into Georgia and the Carolinas, or even run close to the Northeast coast.
 
8 PM EDT intermediate advisory in from the NHC with winds up to 125 mph:

234529_5day_cone_no_line_and_wind.png


As of now, still forecasting a landfall — barely. At that distance, it probably won’t matter.

Also important to note that Dorian was not forecast to reach this intensity until tomorrow afternoon. Curious to see what changes are made when the forecast is updated for the next full advisory (forecasts are not updated for intermediate advisories).
 
Last edited:
8 PM EDT intermediate advisory in from the NHC with winds up to 125 mph:

View attachment 855443

As of now, still forecasting a landfall — barely. At that distance, it probably won’t matter.

Also important to note that Dorian was not forecast to reach this intensity until tomorrow afternoon. Curious to see what changes are made when the forecast is updated for the next full advisory (forecasts are not updated for intermediate advisories).
NHC just put out a special update. Now a category 4. 130 mph winds. Pressure 950 mb.
 
NHC just put out a special update. Now a category 4. 130 mph winds. Pressure 950 mb.
Strangely enough, I was just about to post a dropsonde measurement in the NE eyewall with a 116 kt surface wind measurement, which would make it a Category 4 under the Saffir–Simpson scale, and speculating that they didn’t receive the data in time for the 8 PM advisory.

It wasn’t supposed to get this strong until tomorrow night, and there’s still a few days and plenty of warm water ahead of it. :(
 
Strangely enough, I was just about to post a dropsonde measurement in the NE eyewall with a 116 kt surface wind measurement, which would make it a Category 4 under the Saffir–Simpson scale, and speculating that they didn’t receive the data in time for the 8 PM advisory.

It wasn’t supposed to get this strong until tomorrow night, and there’s still a few days and plenty of warm water ahead of it. :(
Dr. Knabb on the Weather Channel, who is usually quite accurate said he doesn’t see anything that stops this storm from becoming a cat 5, maybe even tonight. Damn.
 
  • Like
Reactions: jonblatho
Looks like it’s starting to move more westward now too. This storm has a mind of its own but I think the predictions earlier today that it would drift eastwards and miss Florida was more wishcasting than anything else. I’m reading if it further intensifies that would tug it south and west. Anything along the Florida coast will be a disaster but a direct hit near Miami would be devastating.

0a89a38590f92ee1469a46f752273dc182164505bbafdba6b31bb1f95e5735f1.gif
 
Damn, faster than expected. Category 5 wouldn’t surprise me at this point.
Yep. A ’sonde dropped about 45 minutes ago got a surface wind measurement of 131 kt or 150 mph. If that measurement can be replicated or near-replicated on the northern eyewall — I suspect the NHC could take issue with using this measurement by itself for multiple reasons — this thing’s on the doorstep of being a Category 5 hurricane already.

recon_NOAA2-2105A-DORIAN_dropsonde14_20190831-0104.png


Stay tuned...

Edit: Another dropsonde just came in from the north eyewall with a surface wind measurement of 112 kt. We’ll see how the NHC chooses to handle this, but I’d say the south eyewall reading is probably a fluke. The pressure’s a bit lower than I’d expect it to be in the eyewall, and one wouldn’t expect substantially stronger winds in the south eyewall compared to the north eyewall for this storm.

Edit 2: Looking at satellite, the south eyewall dropsonde may also not be a fluke because thunderstorm activity appears to be heaviest right now south of the eye. Next advisory’s in about an hour (11 PM EDT) to see how NHC chooses to handle it.
 
Last edited:
It still has a few days before landfall and there’s no obstacles in sight. Terrifying.

I know there’s a lot of hyperbole these days, but expect to see the word “historic” associated with this storm.
 
Eh, that's from 12Z 08/30 — early this morning. Don’t think the 00Z run is out yet, but I’d be careful using data that old when this much remains in flux.
Oh thanks, I removed it.
It still has a few days before landfall and there’s no obstacles in sight. Terrifying.

I know there’s a lot of hyperbole these days, but expect to see the word “historic” associated with this storm.
140 mph now. I believe that’s only 16 mph from a cat 5. Spare a thought for the Bahamas. The Bahamas are getting slammed no matter what.
 
140 mph now. I believe that’s only 16 mph from a cat 5. Spare a thought for the Bahamas. The Bahamas are getting slammed no matter what.
Looks like they split the difference between the questionable 131 kt observation and the “status quo” observation of 112 kt for this advisory — averaging them comes almost exactly to 140 mph. That recon flight’s on its way out of the storm as another flies in. It’ll be interesting to see what comes with the next flight.

Looks like NHC moved the track just offshore for this advisory:

024334_5day_cone_no_line_and_wind.png


That’d still be devastating for parts of Florida’s Atlantic coast.
 
Strangely enough, I was just about to post a dropsonde measurement in the NE eyewall

I'm sure you know all this (and a lot more) but just for reference.

A dropsonde: Device deployed (literally "dropped") from weather monitoring aircraft to get highly granular data from storm systems. The device can measure atmospheric air pressure, temperature, wind speed and direction, and humidity. It also has a GPS receiver to mark its location.

A dropsonde is a disposable, one-time-use device as they are almost always dropped over the ocean.

Dropsonde.png
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.