ATL: IRMA - Post-Tropical - Discussion

[MatthewsRevenge]

Heading for the Dominican Republic. It will be well above the eye but the wind surge and flooding will come for sure. Stay safe, Dominicans.

[psyclone]

It will be interesting to see if a reduction in peak intensity comes at the expense of an expanding windfield over time

[Sciencerocks]

000
URNT15 KNHC 070523
AF309 1511A IRMA HDOB 47 20170907
051400 1930N 06731W 6978 02473 9243 +180 +085 298068 075 051 003 00
051430 1928N 06731W 6963 02528 9282 +178 +093 294079 084 060 001 03
051500 1927N 06732W 6967 02564 9344 +152 +107 289097 107 113 006 00
051530 1925N 06732W 6936 02641 9421 +116 +109 286117 127 119 006 03
051600 1923N 06732W 6978 02646 9489 +111 +110 291126 133 /// /// 03
051630 1921N 06732W 6967 02730 9570 +102 +100 290111 120 121 041 03
051700 1920N 06733W 6959 02778 9611 +097 +096 290107 110 095 017 00
051730 1920N 06734W 6953 02810 9644 +094 +092 288103 108 095 017 00
051800 1919N 06735W 6971 02794 9656 +095 +092 293102 104 091 013 00
051830 1919N 06736W 6960 02824 9670 +095 +093 298102 105 091 013 00
051900 1918N 06737W 6969 02828 9682 +098 +087 301095 101 088 017 00
051930 1918N 06738W 6968 02840 9702 +095 +076 307096 097 084 010 00
052000 1918N 06739W 6965 02856 9703 +107 +075 313092 096 084 011 00
052030 1917N 06741W 6968 02865 9727 +097 +082 316093 096 082 012 00
052100 1916N 06742W 6971 02877 9752 +088 +085 322095 097 081 020 03
052130 1915N 06743W 6968 02902 9784 +083 +082 319096 099 073 014 00
052200 1913N 06744W 6979 02918 9811 +084 +081 315094 102 072 005 03
052230 1912N 06745W 6961 02950 9815 +095 +076 315083 088 073 004 00
052300 1910N 06745W 6974 03019 9866 +094 +073 314081 083 068 003 00
052330 1908N 06746W 6968 02985 9846 +109 +066 314077 081 060 003 00
$$
;

[Aric Dunn]

This is what it was like in St Thomas USVI.

That might be the most incredible hurricane footage I have ever watched.

Though I doubt he'd be so confident in the structure of that building if he were in an EF4/EF5 tornado.

its good.. though his judge of some of the winds were way off.

but damn some of those gust were probably cat 4 for sure.. someone needs to map that location with radar at that time.

[AutoPenalti]

looks like it has finally weakened. though still a cat 5..

Look at the water it's about to encounter though

[Dean_175]

WIth as long as it has been at 185 mph--is it at all unreasonable to think it may have sustained higher at some point in the past day (Patricia, Dean , Wilma were all under-rated initially) ? Maybe 190 mph in re-analysis or something?

[Blinhart]

WIth as long as it has been at 185 mph--is it at all unreasonable to think it may have sustained higher at some point in the past day (Patricia, Dean , Wilma were all under-rated initially) ? Maybe 190 mph or something?

And you got to think about how much water has been built up for that surge, could we see surges over 30 feet in some areas?

[Aric Dunn]

WIth as long as it has been at 185 mph--is it at all unreasonable to think it may have sustained higher at some point in the past day (Patricia, Dean , Wilma were all under-rated initially) ? Maybe 190 mph or something?

yes very possible.

[Dean_175]

When is the next recon? Surprised she has not strengthened, nor weakened at all since yesterday...

Well it has fluctuated slightly in intensity if you go by pressure, though not by wind speed (though that may change with re-analysis).

[shawn6304]

A question in regards to storm surge, if the storm makes that tight north turn would that lessen the surge as the majority of built up water would be heading NW? Or does it not matter?

[Sciencerocks]

When is the next recon? Surprised she has not strengthened, nor weakened at all since yesterday...

Well it has fluctuated slightly in intensity if you go by pressure, though not by wind speed (though that may change with re-analysis).

I think most of today in re-analysis will probably be dropped to 150-155 knots.

[Sciencerocks]

000
URNT15 KNHC 070543
AF309 1511A IRMA HDOB 49 20170907
053400 1836N 06805W 6973 03102 0005 +089 +069 310042 043 036 003 00
053430 1835N 06806W 6970 03102 9997 +095 +063 315037 041 036 002 00
053500 1833N 06807W 6965 03113 0008 +089 +067 320037 038 035 002 00
053530 1832N 06808W 6971 03110 0006 +095 +064 320040 042 036 005 00
053600 1830N 06809W 6965 03122 0011 +094 +065 321037 039 037 003 00
053630 1829N 06811W 6965 03119 0006 +095 +069 323040 042 038 004 00
053700 1827N 06812W 6969 03116 0006 +096 +066 320039 042 038 003 00
053730 1826N 06813W 6967 03122 0013 +093 +069 322039 040 040 002 00
053800 1824N 06814W 6969 03120 0026 +085 +069 321037 038 038 002 00
053830 1823N 06815W 6969 03125 0019 +094 +066 320038 038 037 002 00
053900 1821N 06816W 6974 03122 0025 +092 +065 322034 039 036 002 00
053930 1820N 06817W 6969 03128 0024 +095 +061 319032 034 035 002 00
054000 1818N 06818W 6967 03132 0030 +094 +057 320030 030 034 001 00
054030 1817N 06819W 6971 03130 0033 +090 +056 323030 030 035 001 00
054100 1815N 06820W 6968 03136 0039 +089 +059 327032 034 035 001 00
054130 1814N 06821W 6964 03140 0055 +076 +063 330034 037 035 001 00
054200 1812N 06823W 6970 03134 0046 +084 +061 333032 032 033 002 00
054230 1811N 06824W 6967 03140 0065 +071 +061 332033 033 031 004 00
054300 1809N 06825W 6971 03136 0071 +069 +060 326034 035 037 009 00
054330 1808N 06826W 6968 03143 0066 +071 +066 326032 035 040 011 03
$$

[Sciencerocks]

000
URNT15 KNHC 070553
AF309 1511A IRMA HDOB 50 20170907
054400 1806N 06827W 6968 03142 0063 +076 +073 314032 034 036 014 03
054430 1805N 06828W 6970 03138 0052 +083 +075 310031 032 030 013 00
054500 1803N 06829W 6967 03145 0045 +089 +070 315031 032 028 005 00
054530 1802N 06830W 6847 03272 0013 +092 +064 313033 034 029 003 03
054600 1800N 06831W 6572 03626 0019 +077 +052 308032 034 /// /// 03
054630 1759N 06832W 6376 03880 0019 +065 +040 309031 031 /// /// 03
054700 1758N 06834W 6170 04151 0018 +049 +027 314029 030 /// /// 03
054730 1757N 06835W 5964 04428 0014 +035 +013 316028 029 /// /// 03
054800 1755N 06836W 5762 04708 0006 +023 -005 312028 029 /// /// 03
054830 1754N 06838W 5575 04974 0006 +005 -010 312028 029 /// /// 03
054900 1753N 06839W 5391 05246 0232 -009 -038 305027 028 /// /// 03
054930 1751N 06840W 5225 05496 0249 -022 -053 306026 026 /// /// 03
055000 1750N 06842W 5084 05714 0264 -031 -066 312028 028 030 001 00
055030 1749N 06843W 4955 05919 0280 -038 -078 318028 030 029 001 03
055100 1747N 06844W 4839 06108 0295 -047 -097 321025 026 027 000 03
055130 1745N 06845W 4746 06264 0308 -054 -132 317024 024 027 000 00
055200 1743N 06845W 4676 06380 0316 -063 -160 320026 027 027 000 03
055230 1741N 06846W 4608 06493 0324 -063 -203 321025 027 026 000 00
055300 1739N 06847W 4539 06612 0333 -070 -224 318023 023 024 000 00
055330 1737N 06848W 4472 06727 0340 -082 -238 309020 023 025 000 03
$$

[Blinhart]

When is the next recon? Surprised she has not strengthened, nor weakened at all since yesterday...

Well it has fluctuated slightly in intensity if you go by pressure, though not by wind speed (though that may change with re-analysis).

I think most of today in re-analysis will probably be dropped to 150-155 knots.

Why would you say that, RECON constantly found SFMR ranging from 155 to 170, so they kept it steady at 160. There is no way they can sample the whole storm so they have to figure out a way to have a level for it.

[verbs]

looks like it has finally weakened. though still a cat 5..

Any idea what's causing it to weaken? Definitely looks worse.

[Aric Dunn]

looks like it has finally weakened. though still a cat 5..

Any idea what's causing it to weaken? Definitely looks worse.

internal issues is best guess. there was clearly a ERC in progress earlier which may have gone through in a obscure way.

however the environment is not the issue... It could also be some land interaction. some inflow is disrupted from PR and soon to be DR.

just have to watch and see.

[wxmann_91]

looks like it has finally weakened. though still a cat 5..

Any idea what's causing it to weaken? Definitely looks worse.

Downsloping flow off PR and Hispaniola... entraining some dry air into the circulation.

[Sciencerocks]

Well it has fluctuated slightly in intensity if you go by pressure, though not by wind speed (though that may change with re-analysis).

I think most of today in re-analysis will probably be dropped to 150-155 knots.

Why would you say that, RECON constantly found SFMR ranging from 155 to 170, so they kept it steady at 160. There is no way they can sample the whole storm so they have to figure out a way to have a level for it.

I didn't see any flight level winds above 163 knts(163x.9 =145 knots at the surface) today and the smrf were more supportive of 150-155knts. Of course, I haven't been as alert on recon as the day before so I may have missed something.

[Dean_175]

When is the next recon? Surprised she has not strengthened, nor weakened at all since yesterday...

Well it has fluctuated slightly in intensity if you go by pressure, though not by wind speed (though that may change with re-analysis).

I think most of today in re-analysis will probably be dropped to 150-155 knots.

Well it has now been dropped (per the update) to 155kt (180mph) and pressure has risen to 921mb. Storm still looks very impressive on satellite- cloudless circular eye,etc. Though it does look a little bit more rugged and the cloud tops near the eyewall are not as cold as they were before. Still very impressive to be maintaining high end cat 5 for this long.

[EquusStorm]

Sure, Irma's structure is a little more ragged and it's definitely weakened a little, but seeing how strong it still is, saying it is weaker is a little like saying being hit by a 140-car coal train is less painful than being hit by a 160-car coal train. When you're an upper end Cat Five, it takes a ton of weakening to not be extremely violent, heh. I'd be a little surprised if it dropped below a 5 before it starts wrapping up its core again, unless land interaction with Hispaniola causes some problems. It might, as I half suspect Puerto Rico might have played a small role with its structural issues earlier, beyond the typical ERC changes.