ATL: IRMA - Post-Tropical - Discussion

[Digital-TC-Chaser]

CIMSS shows next to zero shear for this thing up until landfall. Where is that sounding from?
College of DuPage Weather Lab

[KBBOCA]

Irma is still pounding Anguilla and perhaps St. Maarten/St. Martin not yet in the clear either:

Next in line for Irma's fury:

Based on Storm Carib "How Close Can it Get" tool: http://stormcarib.com/closest1.htm

Anegada & Virgin Gorda & Tortola

Results for Virgin Gorda (18.45N, 64.43W):
The approximate Closest Point of Approach (CPA) is located near 18.5N, 64.4W or about 5.8 miles (9.4 km) from your location. The estimated time of when the center of the storm will be at that location is in about 6 hours and 56 minutes from now (Wednesday, September 6 at 3:48PM AST).

Results for Tortola (18.45N, 64.53W):
The approximate Closest Point of Approach (CPA) is located near 18.6N, 64.5W or about 8.1 miles (13.0 km) from your location. The estimated time of when the center of the storm will be at that location is in about 7 hours and 23 minutes from now (Wednesday, September 6 at 4:18PM AST).

The USVI:

St. John:
Results for St.John (18.35N, 64.73W):
The approximate Closest Point of Approach (CPA) is located near 18.6N, 64.6W or about 19.1 miles (30.8 km) from your location. The estimated time of when the center of the storm will be at that location is in about 8 hours and 13 minutes from now (Wednesday, September 6 at 5:06PM AST).

Results for St.Thomas (18.33N, 64.98W):
The approximate Closest Point of Approach (CPA) is located near 18.7N, 64.8W or about 26.3 miles (42.4 km) from your location. The estimated time of when the center of the storm will be at that location is in about 9 hours and 6 minutes from now (Wednesday, September 6 at 6:00PM AST).


Vieques, PR currently showing to be about 50 miles from center:

Results for Vieques (18.13N, 65.44W):
The approximate Closest Point of Approach (CPA) is located near 18.8N, 65.2W or about 50.1 miles (80.6 km) from your location. The estimated time of when the center of the storm will be at that location is in about 10 hours and 34 minutes from now (Wednesday, September 6 at 7:30PM AST).


Here's the track based on the 05:00 Forecast. (Point is centered on Tortola) But of course the storm is not a point on a line, it's BIG, so even areas 40 - 50 miles from center will likely get hurricane force winds, depending on which quadrant they are in...

[Extratropical94]

Not going for a center pass, maybe because of the islands.

125430 1855N 06259W 6974 03105 9988 +104 +096 119078 080 059 000 00
125500 1856N 06302W 6974 03106 9988 +104 +093 117079 080 061 001 00
125530 1857N 06304W 6975 03104 9995 +101 +100 115080 081 062 000 01
125600 1858N 06306W 6966 03109 0016 +109 //// 109085 088 061 015 05
125630 1859N 06309W 6979 03095 0021 +109 +109 099081 084 061 013 00
125700 1900N 06311W 6978 03091 0015 +110 +110 100083 084 062 007 00
125730 1900N 06314W 6971 03101 0016 +105 //// 103085 087 065 005 05
125800 1901N 06316W 6976 03097 0019 +094 //// 102078 083 064 005 01
125830 1902N 06319W 6974 03100 //// +100 //// 103079 081 064 000 01
125900 1903N 06321W 6974 03098 //// +098 //// 097085 086 062 001 05
125930 1904N 06324W 6805 03314 //// +089 //// 099078 083 /// /// 05
130000 1904N 06326W 6509 03680 //// +070 //// 098079 081 /// /// 05
130030 1905N 06328W 6316 03933 //// +060 //// 096082 083 058 000 05
130100 1906N 06331W 6135 04176 9977 +052 +039 100079 083 058 000 03
130130 1907N 06333W 5945 04408 9953 +040 +026 101078 079 057 000 03
130200 1908N 06336W 5763 04661 9950 +024 +015 101078 078 056 000 00
130230 1909N 06338W 5594 04907 9956 +010 +005 101078 078 057 000 03
130300 1910N 06341W 5433 05155 0201 -002 -008 098076 078 055 000 03
130330 1910N 06343W 5278 05392 0219 -018 //// 096075 076 055 000 05
130400 1911N 06346W 5132 05618 0236 -029 -034 094073 075 053 000 01

[mrbagyo]

 https://twitter.com/worldonalert/status/905410901242777600




 https://twitter.com/the_worldface/status/905413424657698816

[KBBOCA]

An update this a.m. from St. Thomas where they are already getting quite strong wind even though they're still probably about 100 miles from the center

http://stormcarib.com/reports/current/stthomas.shtml

By Jane Higgins
Date: Wed, 6 Sep 2017 09:04:53 -0400

Sleep has been rare for last 4 days. This will be brief. The sea is up and
angry.
Surrounded by grey. Some hard rain, then mist then not. We live off the grid
so use generator to boost batteries. We are watching too much weather channel.
Nauseated about Anguilla, just heard that St Maarten is in the eye.

Brave of our friend Jill NP to be on Red Cross duty in town. They had 58 folks
overnight. She has badges so can drive in curfew. She drove the less than
1 mile to Frenchtown at 6 am and was shocked already. She was stopped
twice, apparently curfew from 6 am today til Thursday 6 pm is being enforced.
GOOD.

Our friends in Lerkenlund north side over a Magens were feeling breezy
by 9:30 last night. We are experiencing the most wind from the North now
ever and we have been in this house since 2001. This house was built in
1964. Not sure if the roof will hold. I have been making big promises to
wind gods to show some mercy. We will start to feel it stronger from the West
soon. Backdoor west side is wearing plywood first time ever. East side shutters
are still cracked open for ventilation but that will change soon. So glad we
had those trees cut in the back just 2 days ago.

This is the most anxious we've ever been about our house.

Stay in touch. Dear family and friends in states , out of energy to answer
texts and emails. Will try to make some calls if landline holds as cell
never works here anyway. Dear islanders, please let us know how it is going.
The wind is so loud now.

[PTPatrick]

St marten pics and info I found online look very bad...quite high surge looked like it was in many buildings. Wind damage appeared extreme. Amazed people got out long enough to film in the eye but it's big eye so hopefully they got a couple hours break.

[Wakeknight]

USVI & BVI web cams

http://newsofstjohn.com/webcams/

[Sanibel]

If we get the weaker west side staying on Sanibel will be the better option than going in to the I-75 parking lot...East trend is huge relief...

[jlauderdal]

If we get the weaker west side staying on Sanibel will be the better option than going in to the I-75 parking lot...East trend is huge relief...

you are in much better shape than 24 hours ago..congrats

[KBBOCA]

More pix from St. Maarten/St, Martin:

 https://twitter.com/spekkers/status/905415236823523328




 https://twitter.com/CayleThompson/status/905406019211165700




 https://twitter.com/la1ere/status/905412878773215233

[Wakeknight]

If we get the weaker west side staying on Sanibel will be the better option than going in to the I-75 parking lot...East trend is huge relief...

Agreed. We are just up the road in Nokomis and are weighing the same options. Will likely stay.

[Janie2006]

I have yet to find any wind reports from the affected islands that are above 120. Here's hoping that the 180 wind estimates are way over-inflated.

They're not "inflated" as we have direct measurement from eyewall dropsondes. Its rare though for land stations to record sustained winds at the official level. For starters, I'm pretty sure I saw data from Barbuda a few pages back that had 155mph gusts before the anemometer failed. But beyond that you have more frictional interaction on land and rarely an official weather station in exactly the right place in the strongest quadrant of the storm.

Another thing to bear in mind is the effect that land, vegetation, and buildings have on wind, which of course plays directly into frictional interactions. If one is right on the coastline in the NE quadrant of the eyewall then there is little doubt that one would experience most, if not all, of the wind strength of that particular hurricane. In Irma's case, one probably wouldn't survive the encounter. However, if one isn't directly on the coast then things like trees, mountains, hills, and buildings play their part in reducing the amount of wind strength experienced. We can presume that NOAA does its best to avoid land interaction in order to get the most precise readings, but it can't be avoided. Like all things in real estate, it's location, location, location.

So, someplace on the islands impacted by Irma is indeed seeing those winds....whether there is an anemometer there to record it is another matter.

[AdamFirst]

 https://twitter.com/AndySlater/status/905419045368942593

[tolakram]

I would like to remind people, with an example from last year, about the typical errors at 5 days. The cone is what you need to pay attention too, not the forecast points. If Irma ends up anywhere within the cone it is NOT A SURPRISE. The cone is generally smaller every year but during the season it is a fixed size based on the error average from previous years.

Explanation here: http://www.nhc.noaa.gov/aboutcone.shtml

5 days is still a ways off and even using 2017 tools the track position at 5 days is just not that accurate. This is why preparation is really important ahead of time because you may not know exactly what will happen until closer to 3 days prior.

Matthew NHC 5 day forecast. Matthew did end up inside the 5 day error cone.



Matthew actual position.


Irma current 5 day forecast.

[weathaguyry]

God bless everyone who stayed to endure the Hurricane in the NE Leewards. I pray that everyone is alive and well, but unfortunately with a Hurricane this strong, that's unlikely

[bluespiderfl]

I'm in Brevard county fl... based on models, could get worst side if tracks up central fl, but if current models and it stays off coast, looks like we will get something but bad? if it does stay off coast of fl will it's intensity stay high (cat 4)???

[tolakram]

 https://twitter.com/EricBlake12/status/905419539109826560




Eric Blake ✔ @EricBlake12
Can't stress this enough- don't make your decisions based on shifting computer models! Use trusted sources like @NHC_Atlantic instead #Irma https://twitter.com/amygodsey/status/905406027214069760 …
9:16 AM - Sep 6, 2017

[abajan]

Here's what it was like in Anguilla a couple hours ago.

[Extratropical94]

AF307 seems to be having communication issues. The last 2 datasets are missing.

[rickybobby]

Was listening to do tremble on 103.3 the vibe and he said it's trending east and Florida should be good. He also said sucks foe people who spent money. I'm like wtf.