ATL: IRMA - Models

[GCANE]

I checked today's best performing model analysis, 3-days out, and a number of the CMC Members have done real well, less than 25 miles.

Latest CMC forecast - impact FL.

IMHO, based on trends, track thru Straits of FL is highly likely.

[stormreader]

In other words, a reincarnation almost perfectly of Donna.

What I always liked about the Donna analog was the fact that it formed at almost the exact same date (Aug 29) in the Cabo Verde Islands area. Donna did not intensify quite as quickly as Irma, but still was a major hurricane well out to sea. Donna peaked at Cat 4 before entering the Keys and turning up into Fl and then paralleling the East seaboard. The similarities are obviously there.

Not sure about the stats on Donna while out in the Eastern Atlanta We didn't have the technology or instruments To track them like we do today

True, we know it was a major well out to sea, but while in the east-central Atlantic our observations were probably limited.

[NJWxHurricane]

HWRF still NW of 06Z

06Z - 17.85N 61.1W (930mb)
12Z - 18.15N 61.6W (925mb)


Aside to Rock:

Run the 06Z IR4 simulated off HWRF-P as it finally finished. Dynomat in the house.
https://www.tropicaltidbits.com/analysi ... 0&ypos=600

good to see

[Michele B]

models are still betting some sort of a low to develop over the MS valley... not buying into it yet..

I don't see it either ? There's really not much coming from the nw atm

It's subtle but it's there. Shortwave troughs going trough a longwave ridge get lost since the relative vorticity of the shortwave gets lost in the negative vorticity of the ridge.

Can you rephrase that in English, please?

[Steve]

LOL GCANE. NDG was mad at it during Harvey.

NAVGEM slightly NE of 06Z run out to 12 hours.

HWRF is moving closer to being due west of the 06Z rather than NW.

57 hours

06Z - 19.15N 64.75W (929mb)
12Z - 19.25N 65.4W (924mb)

[Michele B]

https://weather.us/model-charts/standard/broward/windspeed-barbs/20170910-2100z.html

https://weather.us/model-charts/standard/florida/windspeed-barbs/20170911-0000z.html

So the latest GFS would do this to SE FL.. it's pure model fantasy, but quite interesting to look at.

this what miami was lucky with Andrew because want into south dade

Yes, Miami was spared the worst. By ONE DEGREE. Remember that. ONE DEGREE more north, and it would have been a whole different story.

[gatorcane]

Looks like the west shift with HWRF may have stopped also.

[wxman57]

Interesting 12Z GFS - Irma hits SE FL next Sunday, while 94L develops into a hurricane and threatens SE FL the following Sunday. I'm sure that is what will happen...

[wzrgirl1]

Question when does anyone think south florida will be in the 5-day cone? Tonight, or tomorrow?

[Michele B]

I think the pressures on the GFS, given all the land interaction, is way too low and unrealistic. Anybody agree??

I totally agree. If
This thing Goes up the spine of FL interaction with land will weaken her significantly

[WeatherOrKnot]

Interesting 12Z GFS - Irma hits SE FL next Sunday, while 94L develops into a hurricane and threatens SE FL the following Sunday. I'm sure that is what will happen...

Thank you! I was waiting for somebody to acknowledge the absurdity!

[gatorcane]

12Z NAVGEM goes up west coast of Florida:

[weathaguyry]

Trends are starting to make me poke out an eye in NY again, with possible trough at the end that swings this out and back in, if CMC is right. Looking like Donna will be a really good analog, but a disastrous one.

[Steve]

I think the pressures on the GFS, given all the land interaction, is way too low and unrealistic. Anybody agree??

I totally agree. If
This thing Goes up the spine of FL interaction with land will weaken her significantly

But you have to realize it's a Category 5 or a high end 4 at the least under the GFS scenario. So significant weakening is relative and also remember it's with an onshore flow ahead of her. Additionally she's only 100 or so miles inland across FL (the way it appears to me), so when it hits the Atlantic, it should still be intact enough to get Irma back to Cat 2 or 3 for the next landfall if it isn't still that anyway.

[gatorcane]

Slight right shift with 12Z GFS ensembles but more tightly clustered over South Florida

[NJWxHurricane]

Slight right shift with 12Z GFS ensembles but more tightly clustered over South Florida

could be a trend hopefully

[Hurricane Andrew]

If this thing gets far enough away from Hisp/Cuba to avoid significant land interaction, look out! OHC/SSTs in the Straights are unbelievable.

[Hurrilurker]

The good news is, we've pretty much stopped seeing these crazy 880-920 type pressures at US landfall. With all the land interaction forecast they should be significantly higher. We'll see if the models stabilize on that path or shift again though.

[Steve]

HWRF Comparison 78 hours (Thursday 2pm EDT)

https://www.tropicaltidbits.com/analysi ... 0412&fh=78

06Z - 20.55N 69.8W @ 930mb
12Z - 20.65N 70.25W @ 927

A hair WNW of 06Z

Also NAVGEM is a hair NW of the 06Z run as well and about to smack Puerto Rico at 54 hours:
https://www.tropicaltidbits.com/analysi ... s=0&ypos=0

[GeneratorPower]

Slight right shift with 12Z GFS ensembles but more tightly clustered over South Florida

could be a trend hopefully

This is looking like The Big One. Historic possibilities. Typical uncertainties.