ATL: IRMA - Post-Tropical - Discussion

[RL3AO]

So NHC supposes major hurricane strength by 50w, what are the chances it could remain a major for all that time afterward or does the fact that it will happen so early likely mean it will become less intense as time goes on...

If it can avoid major land masses (basically PR and Hispaniola), it could be a major for over a week straight.

[BYG Jacob]

BULLETIN
Tropical Storm Irma Advisory Number 3
NWS National Hurricane Center Miami FL AL112017
1100 PM AST Wed Aug 30 2017

...IRMA EXPECTED TO BECOME A HURRICANE ON THURSDAY...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.4N 32.2W
ABOUT 545 MI...875 KM W OF THE CABO VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES
---------------------------------------------------------------------


Tropical Storm Irma Discussion Number 3
NWS National Hurricane Center Miami FL AL112017
1100 PM AST Wed Aug 30 2017

Irma continues to become better organized, with the development of
a small CDO feature and increased banding near the center. An
earlier high-resolution Windsat microwave overpass showed that Irma
has a tight inner core and a low-level eye-like feature was
present. A Dvorak classification of T3.5 from TAFB is the basis
for the initial intensity of 55 kt. Irma is expected to steadily
strengthen during the next couple of days while it moves through a
low-shear and moist environment, and remains over warm sea
surface temperatures. After that time, slightly cooler SSTs and
lower mid-level moisture may temper the intensification process.
However, the statistical aids, HWRF, and most of the consensus
models make Irma a major hurricane by the end of the forecast
period. The NHC forecast is fairly similar to the previous advisory
through 48 hours, but is above the earlier forecast thereafter. The
new official intensity forecast could still be a little conservative
as it remains a little below the SHIPS/LGEM guidance and the ICON
consensus at days 4 and 5.

Irma is moving westward at about 10 kt to the south of deep-layer
ridge over the eastern Atlantic. The track forecast reasoning is
about the same as the previous advisory, with Irma expected to turn
west-northwestward on Thursday, then continue on that heading
for a couple of days. The high pressure ridge over the central
Atlantic is forecast to strengthen later this week, which is
expected to result in Irma turning west-southwestward by the
weekend. There is still some spread among the track models, so the
NHC forecast lies near a blend of the typically reliable GFS and
ECMWF, and the HFIP corrected consensus.


FORECAST POSITIONS AND MAX WINDS

INIT 31/0300Z 16.4N 32.2W 55 KT 65 MPH
12H 31/1200Z 16.8N 33.6W 65 KT 75 MPH
24H 01/0000Z 17.3N 35.5W 75 KT 85 MPH
36H 01/1200Z 17.7N 37.3W 85 KT 100 MPH
48H 02/0000Z 18.0N 39.5W 90 KT 105 MPH
72H 03/0000Z 17.6N 44.3W 95 KT 110 MPH
96H 04/0000Z 16.8N 49.0W 100 KT 115 MPH
120H 05/0000Z 16.2N 53.5W 105 KT 120 MPH

$$
Forecaster Brown

Another major? Yikes, I hope this stays well away from land.

[SouthFLTropics]

WPTV Channel 5 led their 11:00PM broadcast tonight with Steve Weagle highlighting Irma. Depending on how the next few days play out I'd expect the South Florida media hype to really ramp up by Labor Day.

[TheStormExpert]

So NHC supposes major hurricane strength by 50w, what are the chances it could remain a major for all that time afterward or does the fact that it will happen so early likely mean it will become less intense as time goes on...

If it can avoid major land masses (basically PR and Hispaniola), it could be a major for over a week straight.

That would beat Matthew for longest lived major in a season in quite some time.

[floridasun78]

WPTV Channel 5 led their 11:00PM broadcast tonight with Steve Weagle highlighting Irma. Depending on how the next few days play out I'd expect the South Florida media hype to really ramp up by Labor Day.

weather man Craig Seltzer say too early how far west but say models that turn it north

[JaxGator]

WJXT 4's John Gaughan said on the 10pm newscast that while Irma was days away, it would be the one to watch for Florida and the East Coast depending on how the forecast changes. He didn't hype (he never does), but wanted to get the message out there in advance. I hope the Islands, PR, the Bahamas and Bermuda are keeping taps on this. She's been organizing at a good clip today with great outflow and forming CDO. Its been awhile (since Katia?) to have a Cape/Cabo Verdi storm like this to track.

[Exalt]

WJXT 4's John Gaughan said on the 10pm newscast that while Irma was days away, it would be the one to watch for Florida and the East Coast depending on how the forecast changes. He didn't hype (he never does), but wanted to get the message out there in advance. I hope the Islands, PR, the Bahamas and Bermuda are keeping taps on this. She's been organizing at a good clip today with great outflow and forming CDO. Its been awhile (since Katia?) to have a Cape/Cabo Verdi storm like this to track.

I wish more mets followed Harvey like they are with Irma, I just can't help but feel there wasn't enough early on coverage as soon as the thing popped out into the BoC.

[Aric Dunn]

We have two big hot towers that have fired off. One on tbe sw side and one on the ne side. Looks like the first signs of possible RI.

[painkillerr]

Somewhat more worried here with that track but still is a few days away to know the real deal that the NE Caribbean Islands may endure.

Ditto, I have a bad feeling about this one!

[joey]

WJXT 4's John Gaughan said on the 10pm newscast that while Irma was days away, it would be the one to watch for Florida and the East Coast depending on how the forecast changes. He didn't hype (he never does), but wanted to get the message out there in advance. I hope the Islands, PR, the Bahamas and Bermuda are keeping taps on this. She's been organizing at a good clip today with great outflow and forming CDO. Its been awhile (since Katia?) to have a Cape/Cabo Verdi storm like this to track.

I wish more mets followed Harvey like they are with Irma, I just can't help but feel there wasn't enough early on coverage as soon as the thing popped out into the BoC.

they need to hype this one imo fl is not prepared to handle a major hurricane at a cat 4 or even 5 so hype all u want get the word going and if it doesnt happen all will be fine

[ace]

I wish more mets followed Harvey like they are with Irma, I just can't help but feel there wasn't enough early on coverage as soon as the thing popped out into the BoC.

We have Rita PTSD so Mets are *very careful* when and how they discuss storms now. Even now, they all know about the spin up in the Gulf and Irma, but they are super careful to calmly mention then move along until they have definitive model consensus. Today one Met was literally standing in front of the graphic for an increase in rain next Tuesday and Wednesday because if we hyped it like Florida is doing it would be mass panic.

[Exalt]

I wish more mets followed Harvey like they are with Irma, I just can't help but feel there wasn't enough early on coverage as soon as the thing popped out into the BoC.

We have Rita PTSD so Mets are *very careful* when and how they discuss storms now. Even now, they all know about the spin up in the Gulf and Irma, but they are super careful to calmly mention then move along until they have definitive model consensus. Today one Met was literally standing in front of the graphic for an increase in rain next Tuesday and Wednesday because if we hyped it like Florida is doing it would be mass panic.

There's a difference between hype and simply warning or mentioning a potential for a hurricane making landfall. There were still people on the beaches of SE Texas the day before landfall due to the inconsistent reporting. I get the panic, but you'd think the Rita PTSD would be cause for a more precautionary state of mind..

[SouthFLTropics]

WJXT 4's John Gaughan said on the 10pm newscast that while Irma was days away, it would be the one to watch for Florida and the East Coast depending on how the forecast changes. He didn't hype (he never does), but wanted to get the message out there in advance. I hope the Islands, PR, the Bahamas and Bermuda are keeping taps on this. She's been organizing at a good clip today with great outflow and forming CDO. Its been awhile (since Katia?) to have a Cape/Cabo Verdi storm like this to track.

I wish more mets followed Harvey like they are with Irma, I just can't help but feel there wasn't enough early on coverage as soon as the thing popped out into the BoC.

they need to hype this one imo fl is not prepared to handle a major hurricane at a cat 4 or even 5 so hype all u want get the word going and if it doesnt happen all will be fine

Too much hype early on for a possible non event leads to complacency in the future. It's a fine line they have to tread.

[Blinhart]

They way these models are going, won't be long until we see it go through the Lesser Antilles and then go through the Caribbean, then go in between Cuba and Mexico and not make any significant landfall until the Gulf Coast.

[Mouton]

John G is excellent. I am fortunate to share a note with him from time to time. He believes it is too early to make a call but his mentioning this as early as he has means he is concerned. He will not over hype it, not his style which is measured and calculated to get attention without having one run about with their hair on fire or to not care enough.

Bastardi has been on this one for the past two days also. His and John G.'s style are dissimilar but interestingly their info is generally congruent.

[CrazyC83]

WJXT 4's John Gaughan said on the 10pm newscast that while Irma was days away, it would be the one to watch for Florida and the East Coast depending on how the forecast changes. He didn't hype (he never does), but wanted to get the message out there in advance. I hope the Islands, PR, the Bahamas and Bermuda are keeping taps on this. She's been organizing at a good clip today with great outflow and forming CDO. Its been awhile (since Katia?) to have a Cape/Cabo Verdi storm like this to track.

I wish more mets followed Harvey like they are with Irma, I just can't help but feel there wasn't enough early on coverage as soon as the thing popped out into the BoC.

Harvey didn't scream major threat until last Wednesday, which was less than 60 hours from landfall.

[meriland29]

GFS is in lala land as per 00z, while the EC hit is not out of the question, chugging through that ridge like it was nothing and being unaffected by it is. Unless there is something in physics, or climatology that can explain that, size, perhaps? Strength? Iono, Euro should be more honest...

[Bocadude85]

As far as I know the USA has never been struck by two category 4 or higher hurricanes in the same year, however the USA has been struck by multiple major hurricanes in the same year. Not that any of this information means anything but it is still a interesting stat.

[Cyclenall]

As far as I know the USA has never been struck by two category 4 or higher hurricanes in the same year, however the USA has been struck by multiple major hurricanes in the same year. Not that any of this information means anything but it is still a interesting stat.

For years I was bringing up the equilibrium concept of hurricane seasons and after the 12 year "no majors hitting US" drought isn't it interesting that when one finally hit it wasn't just any category 3 TC, but what is guaranteed to be the costliest natural disaster in American history? Happens to be a rare (even more so) CAT4 strike. Whether or not Harvey was enough to make up for 12 years of no 100 knot winds occurring there is the question. Equilibrium - that's the policy.

[LarryWx]

Per records from 1851 through 2017, I found 51 TC's that moved between 14N and 20N when crossing 30W. Out of these 51, 6 (12%) hit the CONUS (5 of these 6 between 14N and 15N with the other being between 15N and 16N), 14 (27%) dissipated over open water, and 31 (61%) recurved east of the CONUS.