ATL: IRMA - Post-Tropical - Discussion

[Patrick99]

Trust me, I'm not banking on it missing to the east. We can hope, though. This current intensity forecast has me worried, to say the least. At this point, if you said I'd take a direct hit from a Cat 3, I'd take that and be comparatively happy about it, judging against where things stand now.

[Callista]

Oh my god, oh...my god. I am crying right now cause I just woke up and saw the storm is at 175 MPH... I feel...SO bad for those islands approaching right now (puts hands over mouth) I have no other words.. I can't believe that speed..

Hey now. Breathe. I know a lot of us are nervous too and don't want to see this storm make landfall. But we humans are good at helping each other, and I am sure there will be ways to donate to the people who will be housing evacuees and pitching in with the cleanup. We're a tough species. We'll get through this.

I have a request: Can we make a stickied relief thread for major hurricanes that hit land? I know we're all here mostly for the science, but nobody likes to see other human beings hurt or homeless. It would be really great if we could gather a list of good, legit organizations that will be working to help people hit by these storms.

[Patrick99]

Meteorologist Bryan Norcross pointed out in tweets this morning that Irma's hurricane force wind field is wider than South Florida and it won't take a direct hit to produce Wilma type winds and storm surge on both coasts.

Absolutely, we are almost certainly getting *something*......doesn't seem to be much doubt about that.

[Ken711]

Hurricane Irma Discussion Number 26
NWS National Hurricane Center Miami FL AL112017
1100 AM AST Tue Sep 05 2017

Irma is an extremely impressive hurricane in both infrared and
visible satellite images. Experimental GOES-16 one-minute visible
satellite pictures show a distinct 25-30 n mi wide eye with several
mesovortices rotating within with eye. The aircraft have not
sampled the northeastern eyewall where the strongest winds were
measured shortly before 1200 UTC this morning, but the Air Force
plane will be entering the eye in that quadrant momentarily. A peak
SFMR wind of 154 kt was reported, with a few others of 149-150 kt.
Based on these data the initial intensity is set at 155 kt for this
advisory. This makes Irma the strongest hurricane in the Atlantic
basin outside of the Caribbean Sea and Gulf of Mexico in the NHC
records.

[znel52]

Irma up to 155kt (180mph)!!!! Hurricane Allen 1980 is still the record holder for sustained winds correct? 190mph

[RL3AO]

I'm surprised we're getting 155kt winds with such a large storm. The pressure is rather high for a cat 5.

[tolakram]

000
WTNT41 KNHC 051446
TCDAT1

Hurricane Irma Discussion Number 26
NWS National Hurricane Center Miami FL AL112017
1100 AM AST Tue Sep 05 2017

Irma is an extremely impressive hurricane in both infrared and
visible satellite images. Experimental GOES-16 one-minute visible
satellite pictures show a distinct 25-30 n mi wide eye with several
mesovortices rotating within with eye. The aircraft have not
sampled the northeastern eyewall where the strongest winds were
measured shortly before 1200 UTC this morning, but the Air Force
plane will be entering the eye in that quadrant momentarily. A peak
SFMR wind of 154 kt was reported, with a few others of 149-150 kt.
Based on these data the initial intensity is set at 155 kt for this
advisory. This makes Irma the strongest hurricane in the Atlantic
basin outside of the Caribbean Sea and Gulf of Mexico in the NHC
records.

Irma is expected to remain within low vertical wind shear, a moist
mid-level atmosphere, and high upper-ocean heat content as it moves
west-northwestward during the next several days. These conditions
should allow the hurricane to remain very intense throughout much
of the forecast period, however, fluctuations in intensity are
likely to occur as eyewall replacement cycles take place. The NHC
intensity forecast is near the upper-end of the guidance and assumes
little overall interaction of Irma with the islands of the Greater
Antilles.

Irma continues to move westward at about 12 kt, and a strong
subtropical ridge centered over the central Atlantic should steer
Irma generally westward today. The ridge is expected to remain in
place over the western Atlantic during the next several days and
Irma is forecast to move west-northwestward throughout the most of
remainder of the forecast period. Around day 5, a shortwave trough
dropping southward over the central United States is expected to
begin eroding the western portion of the ridge, allowing a Irma to
gain some latitude. The new NHC track forecast is close to the
HFIP corrected consensus model and is very similar to the previous
forecast.

Since Irma is a large hurricane, users are reminded to not focus on
the exact forecast track since tropical-storm and hurricane-force
winds and life-threatening storm surge extend far from the center.
Residents in the Leeward Islands should complete their preparations
very soon as the weather will begin to deteriorate over the
easternmost Leeward Islands later this afternoon.


KEY MESSAGES:

1. Irma is a potentially catastrophic category 5 hurricane and will
bring life-threatening wind, storm surge, and rainfall hazards to
portions of the northeastern Leeward Islands beginning later today
and the Virgin Islands and Puerto Rico beginning tomorrow.
Preparations should be rushed to completion before the arrival of
tropical-storm force winds later today in the Leeward Islands and
tomorrow morning in Virgin Islands and Puerto Rico.

2. Hurricane watches have been issued for portions of the Dominican
Republic and Haiti, the southeastern Bahamas and Turks and Caicos,
and Irma could bring dangerous wind, storm surge, and rainfall to
those areas on Thursday and Friday.

3. Irma could directly affect the remainder of the Bahamas and Cuba
as an extremely dangerous major hurricane later this week. Residents
in these areas should monitor the progress of Irma and listen to
advice given by officials.

4. The chance of direct impacts from Irma later this week and this
weekend is increasing in the Florida Keys and portions of the
Florida Peninsula. However, it is too soon to specify the timing
and magnitude of the impacts. Elsewhere, it is too early to
determine what direct impacts Irma might have on the continental
United States. Everyone in hurricane-prone areas should ensure that
they have their hurricane plan in place.

FORECAST POSITIONS AND MAX WINDS

INIT 05/1500Z 16.8N 58.4W 155 KT 180 MPH
12H 06/0000Z 17.2N 60.3W 155 KT 180 MPH
24H 06/1200Z 18.1N 63.0W 150 KT 175 MPH
36H 07/0000Z 19.1N 65.9W 145 KT 165 MPH
48H 07/1200Z 20.1N 68.7W 140 KT 160 MPH
72H 08/1200Z 21.4N 74.0W 135 KT 155 MPH
96H 09/1200Z 22.7N 78.3W 130 KT 150 MPH
120H 10/1200Z 24.4N 81.2W 125 KT 145 MPH

$$
Forecaster Brown

[Bamagirl2408]

Curious where the Pro Met tread went... and where's Ort when we need him?

He is on Twitter

[MississippiWx]

Hurricane Irma Discussion Number 26
NWS National Hurricane Center Miami FL AL112017
1100 AM AST Tue Sep 05 2017

Irma is an extremely impressive hurricane in both infrared and
visible satellite images. Experimental GOES-16 one-minute visible
satellite pictures show a distinct 25-30 n mi wide eye with several
mesovortices rotating within with eye. The aircraft have not
sampled the northeastern eyewall where the strongest winds were
measured shortly before 1200 UTC this morning, but the Air Force
plane will be entering the eye in that quadrant momentarily. A peak
SFMR wind of 154 kt was reported, with a few others of 149-150 kt.
Based on these data the initial intensity is set at 155 kt for this
advisory. This makes Irma the strongest hurricane in the Atlantic
basin outside of the Caribbean Sea and Gulf of Mexico in the NHC
records.

That is significant.

[gatorcane]

snippet from NHC 11AMEST discussion:

This makes Irma the strongest hurricane in the Atlantic
basin outside of the Caribbean Sea and Gulf of Mexico in the NHC
records.

[Michele B]

"Do not ride it out" - means WHAT??

12million people cannot evacuate the state of FL, and the islands cannot evacuate AT ALL.

All flights out of PBI are full for Wed/Thu/Fri, checking FLL now, but I expect the same... and there are no more reservations in any hotel (that isn't on either coast) until you get to Albany, Georgia.

What the hell do you want us to do? We might not have any CHOICE but to ride it out. The other coast of Florida isn't out of the woods yet. I resent the implication that we are idiots if we are forced to stay here... I'm terrified enough.

Any chance of heading toward southeast Alabama? It's far enough inland that you would likely be fine. I understand your stress right now. I'm hoping for the best for you.

I live in a little town in the middle of the state.

Already people here are freaking out. Hubs had to get gas this morning. He said he was "only" fourth in line! LOL 13 years ago, Charley came right over top of us. People here remember.

If we took off right now for points north, and AL, we likely would ALREADY have a drive twice as long as a normal trip would take. People are taking this very seriously, and the window is quickly closing for evacs. This is why I think if one is planning to go, one needs to do it earlier rather than later.

I guess there's good news in having serious storms "hit" (or nearly hit as Matt did) every year, so people don't forget and get complacent.

[caneman]

Irma up to 155kt (180mph)!!!! Hurricane Allen 1980 is still the record holder for sustained winds correct? 190mph

Yes

[CrazyC83]

Irma up to 155kt (180mph)!!!! Hurricane Allen 1980 is still the record holder for sustained winds correct? 190mph

Correct (pending reanalysis), but this is the strongest ever east of 75°W.

[O Town]

Eye showing up well now on radar.


http://www.meteofrance.gp/previsions-me ... r/antilles

[Hypercane_Kyle]

MSLP down to ~924mb per recon.

[Vdogg]

Surprisingly enough, looks like gfs has nailed the intensity, even if the pressures are off. A rare and dubious "win" for that model (I hesitate to call anything a win under these circumstances). Here's hoping that its latest trend east is also correct.

[KBBOCA]

This is the skeetobite 24 hour map showing the forecast for Irma from the 5 a.m. update when Irma was still a Cat 4.

http://www.skeetobiteweather.com/

Shows quite well which Islands will be within the Hurricane force vs. Tropical Storm winds:

[CrazyC83]

000
URNT15 KNHC 051448
AF309 0811A IRMA HDOB 35 20170905
143930 1658N 05803W 6961 02929 9825 +089 +089 156127 128 096 028 00
144000 1657N 05804W 6980 02892 9801 +091 //// 160130 134 103 021 05
144030 1656N 05805W 6969 02880 9773 +096 +096 163133 137 107 039 03
144100 1656N 05806W 6968 02854 9741 +098 +098 162138 141 105 065 03
144130 1655N 05807W 6951 02854 9720 +098 +098 160138 140 123 062 03
144200 1655N 05809W 6979 02791 9681 +102 +102 161140 142 122 073 03
144230 1654N 05810W 6963 02782 9645 +106 +106 161136 141 146 070 00
144300 1654N 05811W 6960 02746 9600 +111 +111 164133 135 147 067 00
144330 1653N 05812W 6979 02689 9560 +114 +114 162130 134 143 048 03
144400 1653N 05814W 6969 02661 9512 +111 //// 161128 130 147 025 01
144430 1652N 05815W 6948 02637 9460 +111 //// 159112 128 144 012 05
144500 1652N 05817W 6970 02556 9332 +131 //// 154094 101 128 001 05
144530 1651N 05819W 6970 02526 9284 +175 +143 152069 086 069 000 00
144600 1650N 05820W 6971 02504 9253 +185 +146 149046 058 063 002 03
144630 1649N 05822W 6972 02498 9236 +198 +142 149024 036 039 001 00
144700 1648N 05823W 6968 02505 9257 +176 +144 153014 017 030 000 00
144730 1648N 05825W 6973 02499 9277 +155 +145 169012 014 029 000 00
144800 1647N 05827W 6968 02505 9279 +153 +131 155013 014 027 000 03
144830 1647N 05829W 6962 02505 9264 +163 +128 149011 013 026 001 00
144900 1646N 05830W 6969 02492 9247 +179 +115 021002 009 026 001 00
$$
;

142 kt FL, 147 kt SFMR. Pressure 924mb.

[NDG]

History in the making, wow!

This makes Irma the strongest hurricane in the Atlantic
basin outside of the Caribbean Sea and Gulf of Mexico in the NHC
records.

http://www.nhc.noaa.gov/text/refresh/MI ... 1446.shtml

[Michele B]

There was some scuttlebutt on the model thread about models trending east and possibly just missing Florida.....I don't follow the models so closely, any possibility to this?

Yes and no. In other words, if you don't follow the models then just pay attention to the NHC, they out perform individual models almost all the time.

Models will wind shield wiper back and forth narrowing down a solution. The further out in time the more inaccurate they are. Right now it's a little too soon to say for sure. One day could be east, the next one west.

Exactly. Quit focusing on one model or another and from run to run people. There is wide and general consensus on a hit on Florida. The average or blend being up the middle of the state. Until or unless that blend changes. Get prepared

As I stated earlier this morning, this is a very big storm, and a very skinny state! Even if it rakes up the east coast, there will be very high winds felt on the west side, and vice versa! Focusing just on that little skinny line doesn't really give you a good sense of how dangerous this is going to be for ALL in FL.