August 2017: Looking Back at Harvey 5 Year Later

[sau27]

Another bit I would add that I expressed to my family was to make sure you have a way to get tornado warnings during this event. It looks like we are going to be on the dirty side for a while which is the preferred location for those spin ups.

[BlueJay]

Thanks Andrew. Good advice.
I see where the School Closure list is growing by the hour.

[davidiowx]

18z GFS at hour 42. Fairly similar to the last run, but a little more north.

[wxman57]

VERY busy at work today. Have just a minute to check on the forum. Harvey is strengthening rapidly, could well be a Cat 4 when it hits north of Corpus Christi tomorrow night. Big question is how far inland it gets over the weekend. Euro keeps it near the coast, thus not weakening it too much before it eventually accelerates northeast, passing south of Galveston Tuesday morning as a major hurricane on its way to SW Louisiana. I'm not forecasting that just yet. I have the track moving inland a bit more, and winds near hurricane strength on Tuesday morning as it tracks south of Galveston. Worst conditions in Galveston will be on Monday/Tuesday, not initially. If you have a boat down there, get it out of the water.

We are looking at not only a historic hurricane landfall, but a historic rainfall event for Texas. Where Harvey's center meanders around over the weekend, we could see rainfall approaching 40 inches - or more. In Houston, I'd look for daily amounts in the 3-6 inch range Saturday-Tuesday. Winds here may approach low-end tropical storm conditions around landfall tomorrow night, then die down Saturday/Sunday and increase again to near tropical storm-strength on Tuesday morning, depending on how strong Harvey is then and how close it passes to Galveston. I'm not expecting extensive damage to the power grid in CenterPoint's service area, but there will be outages.

Gotta get back to work...

[DoctorMu]

NHC is getting very, very close to my initial call of Sargent, TX.

Aransas National Refuge may be as good as it gets - I'll call it.

[DoctorMu]

This has got to be a once in a lifetime event. From the major hurricane, to loopy loo, ride the entire coast northeastward and dump 25" or more for so many. We might never see this again.

Floyd in North Carolina is the only thing of this potential magnitude I've seen. It took years to recover.

[TexasBreeze]

18z not much change except it meanders around south central TX instead of the coast and the 12+ inch rains are more widespread to the west more. 16-20 Harris County.

[DoctorMu]

This has got to be a once in a lifetime event. From the major hurricane, to loopy loo, ride the entire coast northeastward and dump 25" or more for so many. We might never see this again.

Floyd in North Carolina is the only thing of this potential magnitude I've seen. It took years to recover.

almost forgot...and Floyd was a Cat 1...it stalled over the coastal plains of eastern North Carolina.

remember, a CAT 3 is about 2.35 times stronger than a CAT 1!

[srainhoutx]

4:55 PM CDT Thursday 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)

[jasons2k]

NHC is getting very, very close to my initial call of Sargent, TX.

Aransas National Refuge may be as good as it gets - I'll call it.

Well I made that call two nights ago (not sure if it was publicly, but what I told close friends). Today, I'd probably be on the other side of the bay closer to Port. O'Connor. Could be like one of the historic Indianola hurricanes.

You just never know about those right hooks at the end. Happened with Charley, Rita, others...impossible to forecast, but definitely possible. A small hook could make a big difference with the coastline shaped like that.

[TexasBreeze]

NHC is getting very, very close to my initial call of Sargent, TX.

Aransas National Refuge may be as good as it gets - I'll call it.

Well I made that call two nights ago (not sure if it was publicly, but what I told close friends). Today, I'd probably be on the other side of the bay closer to Port. O'Connor. Could be like one of the historic Indianola hurricanes.

You just never know about those right hooks at the end. Happened with Charley, Rita, others...impossible to forecast, but definitely possible. A small hook could make a big difference with the coastline shaped like that.

That is so true with lots of NW Gulf systems. The "arc shape" of the coast funnels in surge too.

[Texaspirate11]

Voluntary Evacuations for Bolivar Thursday at 8 a.m.

[TexasBreeze]

Is it just the recent burst of storms or does it seem to be more west than north?

[Rip76]

It's been looking west.

[jasons2k]

Wobble wobble around the mean circ. Overall, a steady NW movement.

[djmike]

When is the next model guidance run? Is it pretty much set in stone a landfall west of matagorda or is it still possible for a further northern shift? Or are we getting to the point that model watching is now irrelevant and we now begin watching the movements of harvey? Thoughts? Thanks in advance!

[Andrew]

A lot of the models indicate a WNW-NW phase over the next 12 hours. Closer to land it then makes a more NW-NNW turn

[davidiowx]

Was just wondering the same thing.. is the convection closer to the center pulling the storm westward? Or is it intensifying and wrapping itself together?

[djmike]

Wow. Sure got quiet. Any thoughts on what the next move may be with harvey?

[Andrew]

Wow. Sure got quiet. Any thoughts on what the next move may be with harvey?

Not much to talk about, recon is still in the storm, models come out in the next couple hours but just basically a watch and see. Here is microwave to track it:

http://tropic.ssec.wisc.edu/real-time/m ... t24hrs.gif