ATL: IRMA - Post-Tropical - Discussion

[jasons2k]

The strongest winds in a hurricane hail from the eastern side, not the western.

Depends on the storm. Ike, for example, had its strongest winds in the SW quadrant during and after landfall.

[meriland29]

Let's check her out..

[GCANE]

Mother of all EWRCs?

[KBBOCA]

Good article from the excellent Capitol Weather Gang folks on Irma's threat, potential impacts, and already some of the records she is breaking:

https://www.washingtonpost.com/news/cap ... abc13a8beb

Two key sections:

1) For Florida it's not so much a question of IF there will be a disaster, but how severe. Yikes:

This historically extreme hurricane, which maintained winds of 185 mph longer than any storm ever recorded, will produce the full gamut of hurricane hazards across the Bahamas and potentially South Florida, including a devastating storm surge, destructive winds and dangerous flash flooding.

The Hurricane Center is urging residents of Florida to rush preparations to completion.

Potential effects on Florida and the Southeast U.S.

In South Florida, this storm is being taken as deadly serious. Coastal areas are being evacuated, shelters are being established, and food and gas supplies have dwindled. Although there is uncertainty in the track and the exact path of the violent eye wall, where winds are the strongest, it will be difficult for the state to avoid a disaster: It’s just a matter of how severe.

2) Irma's place in history. I didn't realize that the US has not had 2 Cat 4+ hits in one season since 1915, and that was the ONLY season in recorded hurricane history in which two Cat 4+ hits happened!

Without a doubt, the World Meteorological Organization will retire the names Harvey and Irma after this season. While there have been several instances of consecutive storm names getting retired (Rita and Stan 2005, Ivan and Jeanne 2004, Isabel and Juan 2003, Luis and Marilyn 1995), the U.S. has only been hit by more than one Category 4+ hurricane in a season one time: 1915. Two Category 4 hurricanes hit in Texas and Louisiana six weeks apart that year.

[Chris90]

Satellite presentation appears to be improving again, and while the winds may be down a touch, dropsondes released during this mission have still showed some strong winds on their way down to the surface. It won't take much to bring them to the surface. It's dangerous to say that the storm looks like it is weakening and may not be a major threat to Florida.

The outflow was probably getting choked by the mountains in Hispaniola, and combined with the eyewall replacement cycles, sfmr measuring 135kts is still exceptionally impressive. I think we've been spoiled by the fact that it's been at 175-185mph for so long that 155mph seems less impressive than it is. It's still quite possible this strengthens again over the Bahamas once it puts some distance between itself and Hispaniola.

If you are in an area threatened by Irma please continue to take it seriously and prepare for the worst, hope for the best.

[ronyan]

000
URNT15 KNHC 071753
AF305 1711A IRMA HDOB 54 20170907
174400 1944N 06914W 6965 03136 //// +085 //// 197057 058 043 002 01
174430 1943N 06913W 6966 03136 //// +086 //// 197056 057 043 002 01
174500 1942N 06912W 6968 03136 //// +085 //// 197054 056 044 002 01
174530 1941N 06910W 6967 03137 //// +085 //// 199054 055 043 002 01
174600 1940N 06909W 6970 03139 0039 +088 +087 202054 055 044 001 01
174630 1939N 06908W 6970 03142 0038 +091 +087 201053 054 044 001 00
174700 1938N 06907W 6965 03149 0041 +095 +084 199052 052 044 002 00
174730 1936N 06906W 6962 03153 0042 +092 +084 198053 054 043 002 00
174800 1935N 06905W 6966 03150 0042 +097 +076 198052 053 044 002 00
174830 1934N 06904W 6969 03149 0050 +092 +076 195054 055 042 002 00
174900 1933N 06903W 6966 03154 0048 +094 +073 197053 055 040 002 00
174930 1932N 06902W 6966 03158 0051 +094 +072 198051 052 040 002 00
175000 1931N 06901W 6973 03150 0058 +090 +077 183050 051 041 001 00
175030 1930N 06900W 6965 03159 0055 +091 +076 184047 049 042 001 00
175100 1929N 06859W 6967 03159 0061 +090 +078 188047 048 046 001 00
175130 1927N 06858W 6967 03161 0058 +091 +079 190047 048 045 000 00
175200 1926N 06856W 6963 03164 0060 +091 +086 188046 049 046 001 01
175230 1925N 06855W 6963 03168 0061 +091 +081 186053 054 047 003 00
175300 1924N 06854W 6969 03160 0079 +080 //// 182047 053 045 004 05
175330 1923N 06853W 6970 03159 0098 +085 +085 189045 048 041 006 00
$$
;

[ronyan]

000
URNT15 KNHC 071803
AF305 1711A IRMA HDOB 55 20170907
175400 1922N 06852W 6955 03175 0092 +084 //// 190044 045 041 006 05
175430 1921N 06850W 6917 03223 //// +080 //// 194046 048 041 003 01
175500 1920N 06849W 6845 03315 //// +073 //// 191048 049 041 004 01
175530 1920N 06847W 6786 03390 0085 +073 +070 190048 049 040 005 00
175600 1919N 06846W 6694 03510 0101 +066 //// 191049 050 043 005 01
175630 1918N 06845W 6617 03612 0107 +054 //// 183049 051 043 005 01
175700 1917N 06843W 6545 03699 0111 +050 //// 181049 051 039 005 01
175730 1916N 06842W 6469 03793 0113 +042 //// 179052 055 041 005 01
175800 1915N 06840W 6404 03880 0132 +033 //// 182056 058 044 006 01
175830 1914N 06839W 6410 03875 0131 +032 //// 179055 059 042 006 01
175900 1913N 06838W 6450 03819 0125 +035 +035 173054 056 039 009 00
175930 1913N 06836W 6441 03835 0119 +034 +031 169056 056 038 007 00
180000 1912N 06835W 6441 03831 0102 +045 +027 170056 057 037 007 00
180030 1911N 06834W 6445 03826 0107 +040 +031 174056 058 037 008 00
180100 1910N 06832W 6443 03833 0101 +044 +031 176055 058 038 006 00
180130 1909N 06831W 6431 03840 0102 +043 +031 176055 057 038 005 00
180200 1908N 06829W 6351 03940 0088 +045 +027 178055 058 034 004 00
180230 1907N 06828W 6193 04151 0084 +035 +008 180053 056 034 002 00
180300 1906N 06826W 5982 04409 0063 +022 -017 172056 057 035 001 00
180330 1905N 06825W 5748 04739 0055 +003 -038 163055 058 034 000 00
$$
;

[Loring]

A few quick clips from St. Maarten, found on Facebook:

https://www.facebook.com/EtterroDnilmoT ... 3642392134

[xironman]

Don't know if it has been mentioned but there is a double max on recon, hence the higher pressure.

That's not why....she's had concentric eyewalls for quote some time...

Well yeah, recon showing a double max is conformation of concentric eyewalls and an ongoing EWRC. It is just using the observational data of recon.

[ronyan]

Irma still doesn't have it's EWRC sorted based on what I'm seeing. Probably due to some restricted outflow from DR.

[KBBOCA]

I'm seeing quite a few tweets, etc. now from NWS offices and VERY respected experts and urging folks not to let down their guard. For instance this from Charleston:

 https://twitter.com/NWSCharlestonSC/status/905851535577501696




and t his from Former NHC director Dr. Rick Knabb:

 https://twitter.com/DrRickKnabb/status/905854631837872129

[ronyan]

000
URNT15 KNHC 071810
AF305 1711A IRMA HDOB 55 20170907
175400 1922N 06852W 6955 03175 0092 +084 //// 190044 045 041 006 05
175430 1921N 06850W 6917 03223 //// +080 //// 194046 048 041 003 01
175500 1920N 06849W 6845 03315 //// +073 //// 191048 049 041 004 01
175530 1920N 06847W 6786 03390 0085 +073 +070 190048 049 040 005 00
175600 1919N 06846W 6694 03510 0101 +066 //// 191049 050 043 005 01
175630 1918N 06845W 6617 03612 0107 +054 //// 183049 051 043 005 01
175700 1917N 06843W 6545 03699 0111 +050 //// 181049 051 039 005 01
175730 1916N 06842W 6469 03793 0113 +042 //// 179052 055 041 005 01
175800 1915N 06840W 6404 03880 0132 +033 //// 182056 058 044 006 01
175830 1914N 06839W 6410 03875 0131 +032 //// 179055 059 042 006 01
175900 1913N 06838W 6450 03819 0125 +035 +035 173054 056 039 009 00
175930 1913N 06836W 6441 03835 0119 +034 +031 169056 056 038 007 00
180000 1912N 06835W 6441 03831 0102 +045 +027 170056 057 037 007 00
180030 1911N 06834W 6445 03826 0107 +040 +031 174056 058 037 008 00
180100 1910N 06832W 6443 03833 0101 +044 +031 176055 058 038 006 00
180130 1909N 06831W 6431 03840 0102 +043 +031 176055 057 038 005 00
180200 1908N 06829W 6351 03940 0088 +045 +027 178055 058 034 004 00
180230 1907N 06828W 6193 04151 0084 +035 +008 180053 056 034 002 00
180300 1906N 06826W 5982 04409 0063 +022 -017 172056 057 035 001 00
180330 1905N 06825W 5748 04739 0055 +003 -038 163055 058 034 000 00
$$
;

[ronyan]

000
URNT15 KNHC 071813
AF305 1711A IRMA HDOB 56 20170907
180400 1904N 06823W 5516 05082 0083 -021 -047 160053 054 032 001 00
180430 1903N 06822W 5346 05342 0261 -042 -055 168052 056 030 001 03
180500 1902N 06821W 5188 05581 0277 -050 -057 165051 055 028 002 03
180530 1900N 06822W 5037 05803 0286 -059 -060 174047 050 031 001 01
180600 1859N 06823W 4884 06044 0301 -061 //// 202042 045 031 001 01
180630 1858N 06823W 4756 06259 0316 -065 //// 208039 042 032 000 01
180700 1856N 06824W 4643 06444 0327 -078 //// 203040 042 032 001 05
180730 1854N 06825W 4542 06605 0333 -085 //// 194039 040 031 002 05
180800 1853N 06826W 4415 06836 0354 -094 //// 195046 048 039 004 05
180830 1851N 06827W 4352 06938 0361 -094 //// 188041 046 038 004 01
180900 1850N 06828W 4281 07070 0370 -103 //// 188037 041 038 004 01
180930 1848N 06829W 4168 07274 0385 -119 //// 193042 044 036 001 01
181000 1846N 06830W 4103 07397 0390 -126 //// 195043 045 047 000 05
181030 1845N 06831W 4095 07461 0401 -128 //// 194043 046 /// /// 05
181100 1843N 06831W 4091 07404 0388 -133 //// 191041 046 /// /// 05
181130 1841N 06832W 4097 07364 0353 -134 //// 211035 036 /// /// 05
181200 1840N 06833W 4094 07310 0318 -132 //// 216034 036 /// /// 05
181230 1838N 06834W 4097 07309 0305 -134 //// 216038 040 /// /// 05
181300 1836N 06835W 4096 07332 0337 -135 //// 212040 041 /// /// 05
181330 1835N 06836W 4094 07365 0331 -135 //// 209041 041 /// /// 05
$$
;

[KBBOCA]

Yup, ANOTHER model run with FL in its crosshairs... but just a bit further west.
12Z ECMWF:

Again, this is a MODEL, not the official NHC forecast track. But the ECMWF is about the most respected model there is. NHC won't be taking this lightly. The consensus of the best models seems to continue to show South FL in extreme danger, and the SW coast is not out of danger yet. All of FL peninsula is in the cone. MUST take Irma seriously:

 https://twitter.com/RyanMaue/status/905857734746222593

[BlueWater36]

All,

My wife, two friends, two cats, and two dogs are leaving port saint lucie shortly. We originally planned to stay. It isn't worth it.

We're taking back roads north west through the state in two fuel efficient cars. We have 30 gallons of extra gas on top of our full tanks. Going to family in the pan handle.

I've lurked here for many years and I have learned a tremendous amount about storms from all of your knowledgeable posts. I wish you all the best through this storm and I will check in once we have arrived safely to our destination.

Best of luck to all.

[dexterlabio]

Easy to believe recon getting the weakest sampled wind speed in the NW eyewall. Based on IR sat imagery, the NW quadrant is quite not healthy. Irma could weaken into borderline Cat4/5, but I believe it could regain strength as it closes Cuba and SE Florida..

[newtotex]

Yup, ANOTHER model run with FL in its crosshairs... but just a bit further west.
12Z ECMWF:

Again, this is a MODEL, not the official NHC forecast track. But the ECMWF is about the most respected model there is. NHC won't be taking this lightly. The consensus of the best models seems to continue to show South FL in extreme danger, and the SW coast is not out of danger yet. All of FL peninsula is in the cone. MUST take Irma seriously:

 https://twitter.com/RyanMaue/status/905857734746222593

What winds does 945mb equate to?

[KBBOCA]

Mods, feel free to move to the Preps thread if you think it best, but I've been seeing this article on Twitter a lot today. Thought it might be worth posting here.

New study suggests it best to close interior doors during severe wind events to help protect your roof.

https://disastersafety.org/ibhs-news-re ... ign=buffer

TAMPA, September 6, 2017 – Following rigorous scientific wind testing on a full-scale, 1,400 square foot single-story home in its unique laboratory this summer, the Insurance Institute for Business & Home Safety (IBHS) has important new guidance for all homeowners preparing for major wind storms such as Hurricane Irma: close all interior doors, in addition to all windows and exterior doors.

High winds, such as those currently expected from Hurricane Irma, place homes under intense pressure. Wind entering the home through an open or broken window, can create strong upward pressure on the roof. Closing interior doors helps compartmentalize the pressure inside the home into smaller areas reducing the overall force on the roof structure, which gives the roof a better chance of staying intact.

“The roof is your first line of defense against anything Mother Nature inflicts on a home, and during a bad storm your roof endures fierce pressure from wind, rain, and flying debris that may be outside,” said Julie Rochman, IBHS president and CEO. “But the roof also must withstand internal pressure if winds get inside. The pressure in your home can build like air in a balloon, eventually causing the roof to fail and blow apart, which – particularly in a hurricane – allows water to come pouring in.”

As the eastern United States and Caribbean islands prepare for Hurricane Irma, IBHS urges homeowners to follow all evacuation orders and be sure to shut the doors on Irma to increase its ability to withstand the storm.

Quite a few respected mets have been tweeting this out, so I thought I'd post it here.

[KBBOCA]

More on the 12Z ECMWF:

 https://twitter.com/RyanMaue/status/905855755831701505

[ronyan]

181400 1833N 06837W 4091 07342 0317 -133 //// 206039 042 /// /// 05
181430 1831N 06838W 4094 07347 0332 -134 //// 205040 041 /// /// 05
181500 1829N 06838W 4091 07359 0325 -136 -143 206044 045 /// /// 03
181530 1827N 06838W 4094 07326 0335 -136 -147 205038 043 /// /// 03
181600 1825N 06839W 4094 07338 0339 -133 -147 211038 040 /// /// 03
181630 1823N 06839W 4098 07355 0345 -133 -140 211042 043 /// /// 03
181700 1821N 06839W 4094 07390 0368 -153 //// 192041 043 /// /// 05
181730 1819N 06839W 4094 07403 0383 -157 -163 189037 041 /// /// 03
181800 1817N 06839W 4098 07418 0437 -151 -163 184039 041 /// /// 03
181830 1814N 06839W 4090 07447 0413 -142 -195 183034 038 /// /// 03
181900 1812N 06839W 4091 07417 0392 -135 -225 186032 033 /// /// 03
181930 1810N 06839W 4094 07398 0410 -132 -236 185032 032 /// /// 03
182000 1808N 06840W 4093 07416 0406 -130 -257 188031 032 /// /// 03
182030 1805N 06840W 4093 07431 0405 -130 -257 189029 030 /// /// 03
182100 1803N 06840W 4094 07430 0409 -130 -245 189029 030 /// /// 03
182130 1800N 06840W 4098 07421 0410 -130 -245 189028 029 /// /// 03
182200 1758N 06840W 4094 07431 0410 -130 -249 187028 028 /// /// 03
182230 1755N 06840W 4094 07432 0410 -130 -247 186028 028 /// /// 03
182300 1753N 06841W 4094 07427 0410 -130 -243 187027 027 /// /// 03
182330 1750N 06841W 4094 07428 0410 -131 -245 185027 028 /// /// 03

Mission Finished.