ATL: IRMA - Post-Tropical - Discussion

[CryHavoc]

Hi res 1min Visible loop

http://rammb.cira.colostate.edu/ramsdis/online/loop.asp?data_folder=goes-16/mesoscale_01_band_02_sector_05&width=1000&height=1000&number_of_images_to_display=40&loop_speed_ms=80

Pretty clearly a weaker (though still likely Cat 5 power) SW quadrant, but the outflow to the N and E has never looked better.

I have a feeling we'll be telling our children about Irma and how terrifying of a storm she was. Wilma might have been more impressive from a certain perspective, but Irma has to be new representative of an iconic Atlantic Ocean hurricane going forward (or perhaps at worst tied with Gilbert). Big, blue, round eye, impressive symmetry throughout most of her lifespan to date, incredible winds, and continuing to exist as a 185mph storm for an extended period of time.

I really, really, really hope anyone reading this thread doesn't guess that it's going to miss them based on a single model. That could imperil your own life or others. Look at that destruction -- look at that near perfect hurricane. Why would you want to even take a chance at putting yourself in the middle of that? This storm has a really good chance at hitting Florida, and if it does, it's going to kill people. Personal safety, especially if you have a family that depends on you to make decisions, should ALWAYS take precedence in these situations, because they are so so rare and can be devastating. A hurricane doesn't need to kill you to irrevocably change your life. It can maim you, impale you, or shred any chance you have of getting a simple infection cleaned out and stabilized.

Pride is not worth facing one of the strongest storms we have ever seen on our planet. It's just not.

[Raebie]

St. Thomas is getting absolutely pounded on the cam I'm watching.

Link Cam please?

I was watching on Earth Cams on my phone. Looks like the cam just bit the dust. Couldn't see anything before it went down...was totally obscured by the wind/rain. Wild.

[GCANE]

One door off the shed. Then cam stopped.

https://www.youtube.com/watch?v=jXcyJ6OpjGg

I saw that, I hope she's OK.

She's back on again.

Sheds losing it.
Taco truck is a tank.

[1900hurricane]

An outer reflectivity max (developing outer eyewall) is clearly becoming evident on radar. It'll be interesting to see how it progresses. I'm not sure there is a way to know if it's going to progress more traditionally or just sort of meld with the inner like what occurred yesterday.

[caneseddy]

 https://twitter.com/EricBlake12/status/905475395503497217

[jhpigott]

106mph winds gusting to 131 recorded way south and outside of the eyewall at Buck Island??? Am I reading this right?

http://www.windalert.com/spot/48691

[znel52]

Whats causing that weakness on the W/SW side? Shear and/or dry air? Land interaction?

In my amateur opinion it looks like it ingested a little bit of dry air. On IR you can see where a bit of a dry slot formed earlier. However it doesn't appear to be a lot of dry air or anything that is having a major effect on this monster. Please note I may be wrong maybe someone with more experience will chime in.

[Extratropical94]

URNT15 KNHC 061747
AF305 1311A IRMA HDOB 32 20170906
173730 1938N 06311W 6965 03146 //// +088 //// 119062 065 046 003 01
173800 1940N 06311W 6966 03146 0039 +093 +083 123062 063 047 002 00
173830 1942N 06311W 6965 03149 0041 +093 +083 125062 063 045 003 00
173900 1944N 06311W 6967 03148 0043 +094 +077 124061 061 046 003 00
173930 1946N 06312W 6969 03146 0036 +102 +059 122061 061 044 003 03
174000 1947N 06314W 6962 03154 0039 +100 +060 122059 060 /// /// 03
174030 1946N 06315W 6971 03143 0039 +099 +061 122058 059 048 002 00
174100 1944N 06316W 6967 03146 0044 +089 +070 120058 059 048 004 00
174130 1943N 06318W 6968 03142 0059 +082 +079 119062 062 050 005 00
174200 1942N 06319W 6969 03140 0051 +083 +079 118062 063 051 004 01
174230 1940N 06320W 6966 03141 0060 +082 +080 118064 064 050 007 00
174300 1939N 06322W 6965 03137 0064 +085 +085 116065 065 050 011 00
174330 1938N 06323W 6966 03136 0071 +084 +084 114066 067 052 018 03
174400 1936N 06325W 6969 03130 0070 +092 +092 119069 071 051 019 00
174430 1935N 06326W 6970 03127 0060 +096 +096 122068 073 051 022 00
174500 1934N 06327W 6963 03136 0057 +100 +100 121071 073 049 016 00
174530 1933N 06329W 6967 03126 0050 +103 +103 129068 072 048 014 03
174600 1931N 06330W 6970 03124 0040 +105 +105 136064 066 048 012 00
174630 1930N 06331W 6966 03125 0039 +105 +105 133061 066 046 018 03
174700 1929N 06333W 6979 03109 0025 +102 +101 140059 060 050 009 03

[BYG Jacob]

Whats causing that weakness on the W/SW side? Shear and/or dry air? Land interaction?

In my amateur opinion it looks like it ingested a little bit of dry air. On IR you can see where a bit of a dry slot formed earlier. However it doesn't appear to be a lot of dry air or anything that is having a major effect on this monster. Please note I may be wrong maybe someone with more experience will chime in.

Agreed, it wasn't enough to weaken the storm, but it eroded a bit of the SW/W core.

[eastcoastFL]

106mph winds gusting to 131 recorded way south and outside of the eyewall at Buck Island??? Am I reading this right?

http://www.windalert.com/spot/48691

Looks like it according to the nhc update


100 PM AST POSITION UPDATE...
...EYE OF IRMA PASSING OVER THE BRITISH VIRGIN ISLANDS...

A wind gust to 110 mph (177 km/h) has recently been reported at
Buck Island in the U.S. Virgin Islands.

[rickybobby]

Ucf has canceled classes starting tomorrow til Monday.

[WxGuy1]

Something to keep in mind... For a northward moving tropical cyclone, it's a pretty good bet that the western part of the circulation will be significantly weaker than the eastern part. This would be particularly true if the relevant land areas are on the west side (i.e., Irma moving along the east coast of Florida). Of course, you don't need Cat 4-5 winds to cause devastation, and even if the winds are "only" sustained at 90 mph, there would still be pretty tremendous damage produced. However, it's relevant to keep in mind that the size of the area that sees the NHC-assigned maximum sustained winds is very, very small, and it's almost always limited to areas over the water or along the *immediate* coast. Heck, there was an observation site on an island *directly* hit by Irma this morning that had *sustained* winds of "only" 118 mph, which is solid Cat 3-level winds. The anemometer did break, but the "calm" reports occurred as the surface pressure falls were slowing down significantly (indicating that it likely may have been inside the actual eye). In this case, even though it was *in* the eyewall of a high-end Cat 5 hurricane, the site never saw anything more than Cat 3 winds (remember, the Saffir-Simpson wind scale uses 1-min "sustained" winds, not 3-s wind gusts), at least through the time that the equipment stopped reporting. That's the relevance of being on the "weak" side of the hurricane and being in an area with offshore winds (if I recall, the site was on the south side of the island and reporting N or NW winds). Of course I'm not downplaying what is one of the most intense (in terms of sustained wind speeds) hurricanes on record in the Atlantic, but, like in real estate, it's (almost all about) *location, location, location*. I mention this because I think it's important for people who may experience the western periphery a northward-moving Irma to realize that they are, I can say with great confidence 99% of the time, not experiencing the maximum sustained winds that the NHC lists.

Remember that Hurricane Matthew was Cat 3 very near the east coast of Florida and caused "only" $3 billion in damage in that state; Wilma was of similar intensity as it crossed the state but caused ~$20 billion in damage in Florida

[NDG]

St Thomas now in the SW eyewall of Irma, winds have to be gusting at least to a Cat 4 by now.

[jhpigott]

106mph winds gusting to 131 recorded way south and outside of the eyewall at Buck Island??? Am I reading this right?

http://www.windalert.com/spot/48691

Looks like it according to the nhc update


100 PM AST POSITION UPDATE...
...EYE OF IRMA PASSING OVER THE BRITISH VIRGIN ISLANDS...

A wind gust to 110 mph (177 km/h) has recently been reported at
Buck Island in the U.S. Virgin Islands.

That's crazy wind given the location. Looking at the Puerto Rico radar, Buck Island looks to be on the south "weak" side of the storm just barely on the outer fringes of the core.

[storm_in_a_teacup]

Something to keep in mind... For a northward moving tropical cyclone, it's a pretty good bet that the western part of the circulation will be significantly weaker than the eastern part. This would be particularly true if the relevant land areas are on the west side (i.e., Irma moving along the east coast of Florida). Of course, you don't need Cat 4-5 winds to cause devastation, and even if the winds are "only" sustained at 90 mph, there would still be pretty tremendous damage produced. However, it's relevant to keep in mind that the size of the area that sees the NHC-assigned maximum sustained winds is very, very small, and it's almost always limited to areas over the water or along the *immediate* coast. Heck, there was an observation site on an island *directly* hit by Irma this morning that had *sustained* winds of "only" 118 mph, which is solid Cat 3-level winds. The anemometer did break, but the "calm" reports occurred as the surface pressure falls were slowing down significantly. In this case, even though it was *in* the eyewall of a high-end Cat 5 hurricane, the site never saw anything more than Cat 3 winds, at least through the time that the equipment stopped reporting. That's the importance of being on the "weak" side of the hurricane and being in an area with offshore winds (if I recall, the site was on the south side of the island and reporting N or NW winds). Of course I'm not downplaying what is one of the most intense (in terms of sustained wind speeds) hurricanes on record in the Atlantic, but, like in real estate, it's (almost all about) *location, location, location*. I mention this because I think it's important for people who may experience the western periphery a northward-moving Irma to realize that they are, I can say with great confidence 99% of the time, not experiencing the maximum sustained winds that the NHC lists.

Remember that Hurricane Matthew was Cat 3 very near the east coast of Florida and caused "only" $3 billion in damage in that state; Wilma was of similar intensity as it crossed the state but caused ~$20 billion in damage in Florida.

The whole "dirty" vs "clean" side dichotomy raises its head again I suppose.

(I don't know how many people call it that, but where I am from everyone says that. Though I doubt one can really refer to cat-3 winds as "clean.")

[eastcoastFL]

106mph winds gusting to 131 recorded way south and outside of the eyewall at Buck Island??? Am I reading this right?

http://www.windalert.com/spot/48691

Looks like it according to the nhc update


100 PM AST POSITION UPDATE...
...EYE OF IRMA PASSING OVER THE BRITISH VIRGIN ISLANDS...

A wind gust to 110 mph (177 km/h) has recently been reported at
Buck Island in the U.S. Virgin Islands.

That's crazy wind given the location. Looking at the Puerto Rico radar, Buck Island looks to be on the south "weak" side of the storm just barely on the outer fringes of the core.

How many miles from the center is that?

[GCANE]

Shed about to get ripped off its foundation.

[Extratropical94]

URNT15 KNHC 061756
AF305 1311A IRMA HDOB 33 20170906
174730 1928N 06334W 6966 03125 0020 +097 +094 139058 059 051 015 03
174800 1927N 06335W 6960 03131 0022 +104 +104 132062 066 050 020 03
174830 1925N 06336W 6990 03098 0021 +095 +094 131063 064 052 006 00
174900 1924N 06338W 6962 03127 0009 +093 +092 130065 065 048 004 01
174930 1923N 06339W 6968 03119 //// +089 //// 129066 067 052 003 01
175000 1922N 06340W 6966 03119 0008 +093 +085 129066 067 052 003 00
175030 1920N 06342W 6964 03118 0020 +089 +089 131069 072 051 008 00
175100 1919N 06343W 6963 03116 0013 +092 +091 130068 071 049 011 00
175130 1918N 06344W 6963 03113 0002 +091 +091 132070 071 052 005 00
175200 1917N 06346W 6969 03103 9992 +095 +087 134069 070 053 004 00
175230 1916N 06347W 6967 03103 9988 +096 +081 133068 069 052 005 00
175300 1914N 06348W 6970 03097 9973 +107 +073 129065 067 054 003 00
175330 1913N 06350W 6974 03091 9983 +103 +092 131067 068 056 011 00
175400 1912N 06351W 6977 03080 0005 +099 +099 132065 068 055 013 00
175430 1911N 06352W 6972 03091 9999 +101 +101 138069 070 053 021 03
175500 1909N 06353W 6971 03087 9973 +099 +094 136071 071 057 008 00
175530 1908N 06355W 6965 03092 9975 +098 +090 133070 071 054 007 00
175600 1907N 06356W 6967 03085 9972 +094 +083 130072 073 053 006 00
175630 1906N 06357W 6970 03081 9969 +096 +084 131074 075 054 002 00
175700 1905N 06359W 6966 03085 9971 +091 +087 132074 076 055 004 00

[AutoPenalti]

Shed about to get ripped off its foundation.

It's hanging on for dear life.

[davidiowx]

That shed can't be compared to the blue one! They are going to try to strap it down during the eye (at least that's what it sounded like she said)...