Hurricane Harvey: 2017 Central Texas Coast

[Steve Miller]

Thunderstorms are beginning to redevelop near the estimated center. Rather rapid development into a tropical storm is expected during the next 36 hours. A continued northwest track toward the central Texas coast is forecast through Friday. More rapid intensification is expected on Thursday and Friday as Harvey approaches Texas. Current indications are that Harvey will pose a major threat for excessive rainfall and significant inland flooding over portions of Texas Friday through Monday. It is worth noting that Harvey will move slowly over Texas this weekend and may end up moving back over the northwest Gulf early next week resulting in a threat for re-development.

 

[Joerg Kachelmann]

This would be landfall according to the new ECMWF 12z - other parameters via menu, to zoom out use (-), click to zoom in, for pan click into edges. Time zone and units via gear icon top right

https://weather.us/model-charts/euro/951-w-261-n/sea-level-pressure/20170825-2100z.html

Accumulated ECMWF rain until Monday noonish

https://weather.us/model-charts/euro/953-w-320-n/acc-total-precipitation/20170828-1500z.html

 

[MClarkson]

Some of these potential rain totals are massive. Stalled or slow-moving remnants look like the overriding concern from this one. Shades of Allison?

 

[Steve Miller]

The latest from our meteorologists here at WDT:
Tropical Depression Harvey has redeveloped within the northern Bay of Campeche and is forecast to track to the north-northwest towards the southeastern coast of Texas. Over the next 48 to 60 hours, Harvey is forecast to make landfall as a tropical storm with a chance to become a hurricane prior to landfall. Beyond 60 hours, a complex steering environment will be in place leading to Harvey becoming somewhat stationary. The long term forecast track remains uncertain. What does remain certain is the potential for excessive rainfall along the coast of Texas leading to flash flooding and flooding.
http://www.weatherops.com

 

[Steve Miller]

Looks like things are beginning to get underway along the coast, preparation-wise.

Now we wait and watch for the model solution that makes the most sense. Nearly all agree on a stall when it reaches the coast.

 

[Warren Faidley]

Likely not chasing this one due to several factors: There will not be a lot of time for the storm to pile up a decent storm surge. The right front quad will likely (if the current forecast verifies) come inland between Corpis and Galveston, in an area that is not favorable for chasing. Timing is difficult but it appears to be a night falling storm. Agree with others that flooding could be a life threatening event.

 

[Steve Miller]

Rainfall totals in the Houston area across models and then given a weighted average:


Interesting fact. The ### you see for the 12z GFS is 11.84 inches. Our table didn't have the capacity... The 24" rainfall estimates are a thing.

 

[Randy Jennings]

Shades of Allison?

I was thinking the same thing. Despite "just" being a tropical storm and not a hurricane, Allison is the 14th most costly Atlantic storm and ranks right up there with all the major Cat 4 and 5 storms. My grandmother lived in NW Houston at the time, and the damage in her area was far worse from Allison than any hurricane during the time she lived there. I went back and did some reading on Allison, and several of the models have Harvey taking a similar track (a loop) and the slow moving aspect is certainly similar. However, from what I read it sounds like there was a high pressure system closer to the north of Allison that what the models are projecting for Harvey. I also read that with Allison a "subtropical ridge off Florida weakened, while the ridge west of Texas intensified." I haven't seen a strong indication of that with models for Harvey. I wish the WPC surface analysis archive went back that far. I'd be curious to see if anyone else say any strong (or not strong) correlations to Allison.

 

[cstrunk]

Harvey is now a 986 mb, 60 mph Tropical Storm. Rapid intensification overnight. It will be interesting to see if this kind of strengthening can keep up, and for how long...

 

[Bart_Comstock]

Very impressive sat image to wake up to this morning. As mentioned above Harvey 's pressure fell to 986 mb per the Hurricane Hunter's findings (EDIT: DOWN TO 982 mb AS OF 10AM!). Very warm SST and little in the way of shear ahead of Harvey should allow the rapid intensification to continue. Sat scans this morning show that an eyewall is rapidly forming as the CDO gets better organized. It also shows that Harvey is a pretty large storm and the forming eye is in relation small, I imagine that the NHC will account for this in later outlooks and get very bullish in their late day advisories. To add to this, the SHIPS Rapid Intensification indices are incredibly high. It shows a 70% chance the winds in the storm will increase 45kts in the next 36 hours.

I would not be surprised to see it make landfall as a major Cat 3. I also imagine the NHC will be getting more bullish with its advisories today. It's not been since 2008 that Texas has had a landfalling cane, and even longer for the area to be impacted. Let's hope they heed the warnings. When you combine the fact that Harvey will be a major hurricane AND will stall with noah's flood like rainfall rates I imagine this storm can surpass the damage done by Allison and Ike.

Interesting and slightly related note, today is Andrew's 25th anniversary of his landfall.

 

[Warren Faidley]

Wow. I won't re-post the latest NHC discussion regarding Tropical Storm Harvey (10AM 8-24-17) but they are predicting a major hurricane by landfall.

 

[MClarkson]

In addition to the stronger satellite presentation, every model's overnight runs are much stronger. New 12z guidance in shortly though. Good agreement on a stalled or slow moving system after landfall...

 

[MClarkson]

12Z GFS continues to show rapid strengthening up to landfall... as do the NAMs. I trust the NAM flavors a bit less for tropical systems, but some of that might be my old bias from the old eta core.

 

[Steve Miller]

A beautiful satellite image:

See it for yourself as Harvey evolves: http://bit.ly/2vjk8l8
Also, here is something interesting. Check out the loop after landfall. Our mets here are beginning to lean toward a solution that takes Harvey back offshore and potentially seeing him make a secondary landfall in LA.

 

[Bart_Comstock]

I have been looking at that too Steve. One interesting thing will be to see how much the upwelling from the storm affects the SST and how much Harvey re-strengthens when he moves back out to sea. Another thing to consider is how slow the storm will grind over the Corpus area with its eyewall winds as it stalls and turns back around. If it doesn't make it as far inland as forecast you could see really powerful winds grind down on the area it hits, especially if the more bullish runs are to be believed and this storm makes it to Cat 4. The Yucatan couldn't kill it, Texas likely won't kill it, is there anything that can stop the dreaded "ZOMBIE STORM?!?!?!?!" (I just got an idea to pitch to Scifi Channel. Maybe even a Sharknado/Zombiecane cross over? Hmmmm.... October is almost here!)

 

[Michael Nicolaou]

I have been looking at that too Steve. One interesting thing will be to see how much the upwelling from the storm affects the SST and how much Harvey re-strengthens when he moves back out to sea. Another thing to consider is how slow the storm will grind over the Corpus area with its eyewall winds as it stalls and turns back around. If it doesn't make it as far inland as forecast you could see really powerful winds grind down on the area it hits, especially if the more bullish runs are to be believed and this storm makes it to Cat 4. The Yucatan couldn't kill it, Texas likely won't kill it, is there anything that can stop the dreaded "ZOMBIE STORM?!?!?!?!" (I just got an idea to pitch to Scifi Channel. Maybe even a Sharknado/Zombiecane cross over? Hmmmm.... October is almost here!)

Oh, I've been toying with a little idea since after Ike...actually have put some of it to paper... Homage to Mr. Romero.

 

[Warren Faidley]

Really concerned about the lack of attention along the coast / inland about this storm - mostly due to the forecast "Charlie-like" intensity burst and narrowing time frame to take action. I've been on the on the phone with hotels and some friends / chasers in the area and people are just starting to pay attention. I'm scheduled to arrive in Corpus tomorrow AM. Suspect the core will be east of Corpus in the darkness, but anything can happen. Epic flooding will occur, no doubt.

 

[Steve Miller]

Our latest ECM rainfall forecast: Port Lavaca: 40 inches | Victoria: 30 inches | Houston 18 inches | Lake Charles 12 inches.

 

[Bart_Comstock]

The 12z Euro is out to lunch, but sure is fun to watch! Shows a Texas landfall, it moves back out to sea after sitting on Corpus Cristi and got getting further inland, then hitting Lake Charles as a cat 3. While I agree with the idea of it moving back out over the coast and making it to Louisiana it is way off on its intensity forecasts IMHO.

GIF of the EURO here: https://twitter.com/SvrWxChaser/status/900820800630132737

EDIT: MANDATORY EVACUATION issue for Port Aransas, TX. Ferry to remain open until tomorrow morning, not sure about the causeways. Given how flat the island is, and the lack of adequate shelter on it I would not recommend any chaser attempt to ride out landfall on it or any of the islands unless you are Aquaman.

 

[Warren Faidley]

Not the best hurricane situation to chase - bailing on Corpus unless the next update shows a big push to the west - unlikely. Looks like Port Lavaca will be in right front quad, in the dark. ): Maybe a good way to end up stuck in flooding and closed roads for days+. Beginning to think the Glaveston area east might be a better chase location for round two. Fascinating forecast regardless!

 

[Warren Faidley]

Interesting to watch the Funktop IR satellite image over the last few runs. Harvey ejected a large piece of energy towards the NE and has ingested some dryer air. It will be interesting to watch the new few frames to see what happens.

http://www.ssd.noaa.gov/PS/TROP/floaters/09L/imagery/ft-animated.gif

 

[Bart_Comstock]

I have arrived in Corpus Cristi and ready for the storm. 7am update puts Harvey 1mph away from Cat3 rating. Surprised at how much lightning is in the eye wall. Still have plenty of time before land but it has to move over the continental shelf so we shall see how much of a negative impact this will have on Harvey. I still see it being a cat3 at landfall.

 

[Warren Faidley]

IT'S OFFICIAL. The hurricane is here. TWC personnel are moon-walking with 25-45mph gusts!

 

[Jeff House]

I like the Galveston encore much better than Corpus to Pt O'Connor/Lavaca. Left jog would shake me out of CRP and hell no up toward O'Connor. Nowhere really to stay left side of landfall/eyewall. GLS offers spin-up tornado chances tomorrow without the night surge. Be safe!

 

[Steve Miller]

45 to 60-inch totals now being forecast on our latest ECM runs. I honestly cannot tell you the difference between these 12z runs outside of that they come to me from two different departments in the company and serve two separate purposes. Regardless, even 45 inches is a lotta rainfall!