ATL: HARVEY - Post-Tropical - Discussion

[Kingarabian]

The most recent F-16 pass makes me think that Harvey is nearly a lock for an eventual major hurricane.

[img]https://www.nrlmry.navy.mil/tcdat/tc17/ATL/09L.HARVEY/tc_ssmis/91h/1degreeticks/20170824.2158.f16.x.91h_1deg.09LHARVEY.75kts-979mb-244N-936W.95pc.jpg[img]

They are flying f-16s into harvey?

DMSP F-16 satellite.

[AubreyStorm]

It’s correct that post here?

Vía Twitter
Eyewitness viewer, Clarrisa Hernandez, sent this photo in of I-37 evacuation route in Corpus Christi ! Drive safely and prepare for delays.

[txwatcher91]

Massive hot towers firing all around now, eye being obscured and CDO forming a nice circular shape. This is the final step before we see intense pressure drops and wind spiking fast. I expect this will be a category 4 by morning and peak near 160mph, 915mb pressure.

[southerngale]

any one have Jeff Linders email update?

***Major hurricane impact into the TX coast likely Friday night***



***Preparations to protect life and property MUST be rushed to completion in the hurricane warning area***



Hurricane Warning in effect from Port Mansfield to Sargent (extended NE from Matagorda)



Tropical Storm Warning in effect from Sargent to High Island



Storm Surge Warning from Port Mansfield to High Island



Discussion:

USAF plane continues to show pressure falls in Harvey now down to 976mb…that is over 25mb since 400am this morning…which is rapid intensification. The convective pattern continues to look well organized with deep convection wrapped completely around the center and a well formed eyewall with good banding. There is nothing to prevent intensification up to landfall.



Intensity:

Trying to keep up with the intensity changes today has been like chasing running water…looking at a solid (mid to strong cat 3 into the mid TX coast) with sustained winds of 125mph. Could be slightly stronger (130-135mph) which would be cat 4. We are splitting hairs on the damage potential which is extreme. Entire structures will fail under these types of wind loads (Rockport to Port O Connor)



Track:

There has been little change in the track reasoning today which will bring a devastating hurricane to the TX coast. Latest ECMWF run is even slower and now stalls Harvey on the coast or just offshore. NHC guidance keeps it moving just inland. We must get the center inland or the storm will not weaken. Latest reasoning also turns Harvey ESE/E and track it up the upper TX coast to be located over Galveston next Tuesday.



Impacts:



Storm Surge:



Storm surge inundation (will update to the 400pm ADV at 530pm)



http://www.nhc.noaa.gov/refresh/graphic ... n#contents



Life threatening storm surge is likely along the coast from north of Corpus Christi to Sargent including Matagorda Bay.



I want to be very clear on the storm surge levels as there is some confusion on what these numbers are indicating.



All the numbers listed below are ABOVE THE GROUND, not above sea level



Mustang Island to Sargent including Matagorda Bay: 6-12 feet (above the ground)

Sargent to Jamaica Beach: 5-8 ft (above the ground)

Jamaica Beach to High Island: 2-4 ft (above the ground

Galveston Bay (Seabrook, Shoreacres, Nassau Bay, Kemah, San Leon: 2-4 ft (above the ground)



Rainfall:



Dangerous and life threatening flood event is likely over a very large area



Flash Flood Watch issued until further notice



Widespread rainfall amounts of 10-20 inches with isolated totals of 30 inches is possible. Clearly this will be a potentially catastrophic flooding event for a large portion of SC/SE TX and the coastal bend. Major flooding of the Harris County bayous and creeks is very possible along with major to record flooding on some of the rivers over SE TX and the coastal bend.



Winds:



Devastating core winds within the eyewall of Harvey will impact areas from Rockport to Port O Connor



Rockport to Port O Connor: 120-125mph g 130+

Matagorda Bay: 110-115mph g 125

Port O Connor to Sargent: 80-90mph

Sargent to Surfside: 50-60mph

Harris County including Galveston Bay: 45-50mph



The following impacts are expected from Matagorda to Rockport:



- Structural damage to sturdy buildings, some with complete roof

and wall failures. Complete destruction of mobile homes. Damage

greatly accentuated by large airborne projectiles. Locations

may be uninhabitable for weeks or months.

- Numerous large trees snapped or uprooted along with fences and

roadway signs blown over.

- Many roads impassable from large debris, and more within urban

or heavily wooded places. Many bridges, causeways, and access

routes impassable.

- Widespread power and communications outages.



Evacuation Orders:



Mandatory Evacuation: Brazoria County (Gulf of Mexico to the Intracoastal Canal)



Mandatory Evacuation: all Calhoun County (effective immediately)



Mandatory Evacuation: Matagorda County (South of FM 521 and FM 2611 in Sargent), all areas S of FM 521 in Matagorda County, all areas south of Business 35 W of Palacios. All persons under age of 18 must leave the evacuation area



Port Aransas/Aransas Pass: Mandatory evacuation (effective immediately)



Mandatory Evacuation: all San Patricio County (effective at noon today)



Mandatory Evacuation: City of Ingleside (effective immediately)



Mandatory Evacuation: All Refugio County (effective immediately)



Voluntary Evacuation: all Jackson County (effective immediately)



Voluntary Evacuation: western Nueces County



Voluntary Evacuation: all Victoria County



Voluntary Evacuation: all Bolivar Peninsula



Voluntary Evacuation: City of Corpus Christi (effective at noon today)



cone graphic



[Image of WPC QPF U.S. rainfall potential]

[ROCK]

Massive hot towers firing all around now, eye being obscured and CDO forming a nice circular shape. This is the final step before we see intense pressure drops and wind spiking fast. I expect this will be a category 4 by morning and peak near 160mph, 915mb pressure.

915MB 160mph? got a ways to go before that is a possibility...I am thinking high end cat3

[Houstonia]

Sorry for double-posting - you can delete if you would like.

Latest update from Jeff:

**Major hurricane impact into the TX coast likely Friday night***
***Preparations to protect life and property MUST be rushed to completion in the hurricane warning area***

Hurricane Warning in effect from Port Mansfield to Sargent (extended NE from Matagorda)
Tropical Storm Warning in effect from Sargent to High Island
Storm Surge Warning from Port Mansfield to High Island

Discussion:
USAF plane continues to show pressure falls in Harvey now down to 976mb…that is over 25mb since 400am this morning…which is rapid intensification. The convective pattern continues to look well organized with deep convection wrapped completely around the center and a well formed eyewall with good banding. There is nothing to prevent intensification up to landfall.

Intensity:
Trying to keep up with the intensity changes today has been like chasing running water…looking at a solid (mid to strong cat 3 into the mid TX coast) with sustained winds of 125mph. Could be slightly stronger (130-135mph) which would be cat 4. We are splitting hairs on the damage potential which is extreme. Entire structures will fail under these types of wind loads (Rockport to Port O Connor)

Track:
There has been little change in the track reasoning today which will bring a devastating hurricane to the TX coast. Latest ECMWF run is even slower and now stalls Harvey on the coast or just offshore. NHC guidance keeps it moving just inland. We must get the center inland or the storm will not weaken. Latest reasoning also turns Harvey ESE/E and track it up the upper TX coast to be located over Galveston next Tuesday.

Impacts:

Storm Surge:

Storm surge inundation (will update to the 400pm ADV at 530pm)
http://www.nhc.noaa.gov/refresh/graphic ... n#contents
Life threatening storm surge is likely along the coast from north of Corpus Christi to Sargent including Matagorda Bay.

I want to be very clear on the storm surge levels as there is some confusion on what these numbers are indicating.
All the numbers listed below are ABOVE THE GROUND, not above sea level
Mustang Island to Sargent including Matagorda Bay: 6-12 feet (above the ground)
Sargent to Jamaica Beach: 5-8 ft (above the ground)
Jamaica Beach to High Island: 2-4 ft (above the ground
Galveston Bay (Seabrook, Shoreacres, Nassau Bay, Kemah, San Leon: 2-4 ft (above the ground)

Rainfall:

Dangerous and life threatening flood event is likely over a very large area
Flash Flood Watch issued until further notice
Widespread rainfall amounts of 10-20 inches with isolated totals of 30 inches is possible. Clearly this will be a potentially catastrophic flooding event for a large portion of SC/SE TX and the coastal bend. Major flooding of the Harris County bayous and creeks is very possible along with major to record flooding on some of the rivers over SE TX and the coastal bend.

Winds:
Devastating core winds within the eyewall of Harvey will impact areas from Rockport to Port O Connor
Rockport to Port O Connor: 120-125mph g 130+
Matagorda Bay: 110-115mph g 125
Port O Connor to Sargent: 80-90mph
Sargent to Surfside: 50-60mph
Harris County including Galveston Bay: 45-50mph

The following impacts are expected from Matagorda to Rockport:

- Structural damage to sturdy buildings, some with complete roof
and wall failures. Complete destruction of mobile homes. Damage
greatly accentuated by large airborne projectiles. Locations
may be uninhabitable for weeks or months

- Numerous large trees snapped or uprooted along with fences and
roadway signs blown over.

- Many roads impassable from large debris, and more within urban
or heavily wooded places. Many bridges, causeways, and access
routes impassable.

- Widespread power and communications outages.

Evacuation Orders:
Mandatory Evacuation: Brazoria County (Gulf of Mexico to the Intracoastal Canal)
Mandatory Evacuation: all Calhoun County (effective immediately)
Mandatory Evacuation: Matagorda County (South of FM 521 and FM 2611 in Sargent), all areas S of FM 521 in Matagorda County, all areas south of Business 35 W of Palacios. All persons under age of 18 must leave the evacuation area
Port Aransas/Aransas Pass: Mandatory evacuation (effective immediately)
Mandatory Evacuation: all San Patricio County (effective at noon today)
Mandatory Evacuation: City of Ingleside (effective immediately)
Mandatory Evacuation: All Refugio County (effective immediately)
Voluntary Evacuation: all Jackson County (effective immediately)
Voluntary Evacuation: western Nueces County
Voluntary Evacuation: all Victoria County
Voluntary Evacuation: all Bolivar Peninsula
Voluntary Evacuation: City of Corpus Christi (effective at noon today)

[SouthDadeFish]

The low-level structure looks a little asymmetric:



But the mid-levels look better:

[meriland29]

Massive hot towers firing all around now, eye being obscured and CDO forming a nice circular shape. This is the final step before we see intense pressure drops and wind spiking fast. I expect this will be a category 4 by morning and peak near 160mph, 915mb pressure.

By morning? I don't know man, I mean we will see if it drops that low but that might be a far reach...

[meriland29]

The low-level structure looks a little asymmetric:



But the mid-levels look better:

Are asymmetrics indicative of anything in regard to intensity or future intensity?

[Kingarabian]

Overshooting tops obscuring the eye:

A real big one has just gone up on the NW eyewall that is firing alot of lightning as well, this maybe the one that kicks start the next stage of rapid strengthening and takes us down into the 940s in the next 6-9hrs.

Yep, starting to look better on Dvorak. ring is almost circular. Then we'll need to see the eye warm up and be positive, as it's still negative:

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 24 AUG 2017 Time : 214500 UTC
Lat : 24:46:11 N Lon : 93:58:27 W


CI# /Pressure/ Vmax
4.6 / 973.8mb/ 79.6kt


Final T# Adj T# Raw T#
4.6 4.6 4.8

Estimated radius of max. wind based on IR :N/A km

Center Temp : -32.7C Cloud Region Temp : -55.5C

Scene Type : EYE

[Blinhart]

Massive hot towers firing all around now, eye being obscured and CDO forming a nice circular shape. This is the final step before we see intense pressure drops and wind spiking fast. I expect this will be a category 4 by morning and peak near 160mph, 915mb pressure.

By morning? I don't know man, I mean we will see if it drops that low but that might be a far reach...

I wouldn't be surprised to see this being a very high end cat 3, low end cat 4 by 7am, and max winds could be around 160 before landfall, if it does make landfall just North of Corpus Christi, but if it stays off shore the whole time it could get up to say 175. Pressure could range anywhere from 894 to 925.

[SouthDadeFish]

Man this convective burst in the western eyewall is massive. Totally obscured the eye on visible imagery:



It also shows up nice on 85-GHz PCT:

[Langinbang187]

Massive hot towers firing all around now, eye being obscured and CDO forming a nice circular shape. This is the final step before we see intense pressure drops and wind spiking fast. I expect this will be a category 4 by morning and peak near 160mph, 915mb pressure.

By morning? I don't know man, I mean we will see if it drops that low but that might be a far reach...

Little bit of doomcasting. I'd guess it peaks right around what the NHC is predicting.

[Kingarabian]

The low-level structure looks a little asymmetric:

[img]http://i.imgur.com/kHvCMb7.jpg[img]

But the mid-levels look better:

[img]http://i.imgur.com/oBlyQ1E.jpg[img]

Well an hour later and the eyewall has degraded... Guess this is to be expected with all that green confined around the core.

[Cunxi Huang]

eye has been covered by a hot tower convection northwest. I think Harvey might be in CDO pattern next few hours.

[Blinhart]

The low-level structure looks a little asymmetric:

[img]http://i.imgur.com/kHvCMb7.jpg[img]

But the mid-levels look better:

[img]http://i.imgur.com/oBlyQ1E.jpg[img]

Well an hour later and the eyewall has degraded... Guess this is to be expected with all that green confined around the core.

I think what we are seeing is the first of many EWRC, whenever this new eye clears out, I will not be shocked to see a stadium eye where the bottom is about 15 miles wide and the top is about 60 miles wide.

[GalvestonWXGeek]

I have a question that I hope someone can answer:

In the Jeff L. upadates, he references the storm surge numbers are being measured "above the ground". Does anyone know where he might be getting these "above the ground" numbers? My understanding has always been that storm surge was measured as the height of the water above the normal predicted astronomical tide.

The information he has posted is extremely frightening.

[psyclone]

looks like a relentless grind toward Corpus/Port O'Connor in recent imagery.

[MaineWeatherNut]

I have a question that I hope someone can answer:

In the Jeff L. upadates, he references the storm surge numbers are being measured "above the ground". Does anyone know where he might be getting these "above the ground" numbers? My understanding has always been that storm surge was measured as the height of the water above the normal predicted astronomical tide.

The information he has posted is extremely frightening.

You can get all the numbers here - http://www.nhc.noaa.gov/refresh/graphic ... n#contents

[Kingarabian]

The low-level structure looks a little asymmetric:

[img]http://i.imgur.com/kHvCMb7.jpg[img]

But the mid-levels look better:

[img]http://i.imgur.com/oBlyQ1E.jpg[img]

Well an hour later and the eyewall has degraded... Guess this is to be expected with all that green confined around the core.

I think what we are seeing is the first of many EWRC, whenever this new eye clears out, I will not be shocked to see a stadium eye where the bottom is about 15 miles wide and the top is about 60 miles wide.

Don't think it's EWRC. Don't think there was a completed closed eyewall in the first place.