Post Rita Questions

[galvbay]

Two weeks ago we were watching one of the strongest recorded hurricanes develop in the GOM. Hurricane Rita was projected to make landfall in or around the Galveston Island area. Media reported it as ‘the worst case scenario’ with the storm coming through Galveston and into Galveston Bay and up the Houston Ship Channel pushing a tide surge upwards to twenty feet. Experts expected that the communities all along the bay would experience severe tidal flooding. Television showed the animated graphics that showed the areas that would flood. We viewed the photographs surge did to Mississippi from Katrina a few weeks earlier than Rita. We also witnessed the colossal exit of over a million people evacuating the area expecting the same outcome Biloxi had. My question is…..I understand how Biloxi, Pascagoula and the other communities along the mid coast were affected by the surge…but, why do the experts think that Houston would experience the same outcome? We drove along Clear Lake today and I still question ‘where will all of this tidal surge water come from’? Simply put…is there enough water in Clear Lake and Galveston Bay to produce such a huge tidal surge? The only input (replacement water) for the bay is the ship channel pass between Galveston and Boliver, San Luis Pass at the West end of Galveston Island and Roll Over Pass. I just can’t see that there is enough water to meet the expected huge tidal surge the experts warn us about. Someone help me out here! galvbay

[wxmann_91]

A 1928 hurricane hit south Florida as a Cat 4. Winds on the left side of the hurricane drove a huge storm surge on the south coast of Lake Okeechobee. Thousands were killed, and remember this was storm surge from a lake. Galveston Bay is about the size of Lake Okeechobee, and remember that the storm surge in this case comes from the Gulf, which piles up because of the shallower waters and the funneling effect of a bay. So technically the surge will come from the Gulf and not the bay, but the bay makes the surge worse. What though I'm trying to demonstrate is that it does not take a huge body of water for a massive storm surge.

[galvbay]

wxmann.....agree with the storm surge. My question is that the experts were telling us that anything under the 20' elevation would be affected by tital flooding. The Galveston Bay complex is about 30 miles long and 17 miles wide with a depth of 7-9 feet. 'IF' the entire bay was completely emptied and pushed into the warned areas....there isn't enough water to do the flooding that the experts project. Simple math. (just my thoughts, galvbay)

[galvbay]

http://maps.google.com/maps?q=galveston ... rt=0&hl=en

[StormWarning1]

Galvbay, its not just the water in the bay, but all that water in the gulf that is pushed into the bay well before the storm center arrives that causes the storm surge.

If Rita had made landfall SW of Galveston by a few miles then a 15-20 foot storm would occur at Glaveston, 20-25 feet on the west side of the bay and 25-35 feet (storm surge and rainfall runoff) in the ship channel to downtown Houston.

[galvbay]

Stormwarning.....I agree with the massive flooding of Galveston Island with a 20-25 surge...no doubt indeed. I was living on Clear Lake (small lake that joins with Galveston Bay) during Alicia in 83'. We had a storm surge that flooded the immediate adjoining land (maybe one city block with minor street flooding)....but nothing like the 'projected flooding' the media warned about. I guess what I'm getting at is 'what am I going to do next time'? We live in Deer Park....elevation 25+ feet....3-4 miles from the ship channel. We have a vey well built brick home and execellent drainage (did not flood during Allison) and no large trees to fall into the house. I can prep the house for wind but not for the forcasted flooding. I just can't see the numbers adding up for the massive tital surge....there is not enough water in Galveston Bay (and ways to replace it) for this to happen. Thanks for any input or suggestions. galvbay

[artist]

galvbay - don't doubt it if the NHC says it can happen. The surge got (to my understanding) as far as 10 miles inland in parts of Mississippi. Just prepare and if they tell you to evacuate next time do it.

[vbhoutex]

Galvbay, as stated above already, it is not just the water already in the bay, but the incoming surge from the Gulf along with the funneling effect of the narrowing bay that would have helped produce that surge. Look at what happened at Pensacola during Ivan(very similar scenario topography wise). If Rita had come in to the SW of Galveston all of the islands would have been overwashed(under water)completely and areas like the Bolivar Peninsula would look like what used to be Holley Beach(?) and Cameron LA and the MS coast after Katrina. All of that surge would be pushed up into the bay and its estuaries with no place for it to drain to till the winds switched directions to allow the surge to begin to flow back south. On top of that flooding from torrential rains which can't escape due to the surge pushing up the bay would be on top of that. I do understand feeling like you are in good control of your situation and know your home and what has transpired in the past, but when NHC tells me I am in a flood zone and need to evacuate, there will be no question as to what I will do and that is GET OUT!! I am fortunate I am not in that situation.

[f5]

the media loves worst case scenarios beacuse they want to drive up their ratings

[patsmsg]

the media loves worst case scenarios beacuse they want to drive up their ratings

This is a true statement, but the "worst case scenarios" often come from the NHC and are then reported by the media. Don't discount them just because of who the messenger is.

[jasons2k]

I hope you're not suggesting the NHC intentionally makes a forecast based on the 'worst case scenario'. If that were true, Port Lavaca/Palacios would have never been the original landfall point.

I think the NHC strives for nothing less than accuracy.

[galvbay]

I really appreciate the input from the group and for taking my question seriously. Here is a storm surge map of harris county for a Cat 5 storm.....could have been Rita! Anyway.....I'm sitting in Deer Park at 25' above sea level and I'm still having a hard time accepting that they expect flooding (major...houses underwater) in this area. The numbers (water volume) just do not add up to me. galvbay

http://www.dodson-hydro.com/rita/c5surge.JPG

VB....did you stick around or head West for Rita?

[Roxy]

galvbay, I have the same question as you. we live right by Ellington field and they had us in zone c. Call me niave, but I really don't (or rather, didn't) think the water was really going to make it that far inland.

But this has been an interesting thread, and I will certainly take it to heart.

PS, does anyone know where I can find our elevation?

[galvbay]

Roxy...if you have google-earth (if you don't...GET IT!)..it will show your elevation. We use to live around the corner from you....the patio homes across from Bay Oaks. The only concern I would have with that area is Horsepen Bayou (starts behind the Randal's) backing up. galvbay

[galvbay]

http://www.dodson-hydro.com/rita/

http://earth.google.com/

[Roxy]

Roxy...if you have google-earth (if you don't...GET IT!)..it will show your elevation. We use to live around the corner from you....the patio homes across from Bay Oaks. The only concern I would have with that area is Horsepen Bayou (starts behind the Randal's) backing up. galvbay

I have google earth, it really is cool..isn't it. I guess I missed the part where it tells me elevation...I will look again. I know exactly where you are talking about, we are in Northfork.

We are easily 15 miles from the bay, but only about 5-10 from the lake. There are some bayous, but our neighborhood has HUGE empty gullys all around it to catch water. I just don't buy the massive flooding in this area scenario. I will check out elevation and recant if it's too low....

edited to add: ok,we are at 23 feet...I guess that is a little concerning.

[galvbay]

My thoughts exactly. I just can't see enough water leaving Clear Lake and being replaced through the small channel at Kemah. Granted, Kemah, Seabrook, Baycliff, Shore Acres on the bay side would take a major hit with a cat5 surge but I still doubt that it would flood everything out to I45 from Texas City to Pasadena. Morgan's Point, some parts of LaPorte would also see surge problems....but Ellington Field at 32' http://www.airnav.com/airport/KEFD...I still don't see it. galvbay

[galvbay]

Interesting poll on Houston Rita evacuation....'Would You Evacuate Again????'

http://www.chron.com/cs/CDA/ssistory.mp ... ry/3384384

[jasons2k]

My thoughts exactly. I just can't see enough water leaving Clear Lake and being replaced through the small channel at Kemah. Granted, Kemah, Seabrook, Baycliff, Shore Acres on the bay side would take a major hit with a cat5 surge but I still doubt that it would flood everything out to I45 from Texas City to Pasadena. Morgan's Point, some parts of LaPorte would also see surge problems....but Ellington Field at 32' http://www.airnav.com/airport/KEFD...I still don't see it. galvbay

Many people in MS couldn't imagine anything worse than Camille's surge and look at what happened.

Trust the science; otherwise you're playing roulette with six bullets, not one.

[jeff]

The Wednesday 1000pm forecast track on 9/21 was the worst case track for Houston/Galveston. A major hurricane striking at Freeport or the west end of Galveston Island with a tremendous surge into Galveston Bay from the Gulf. A cat 3 or higher storm will sweep the Gulf surge across Galveston Island and the Bolivar Peninsula (so Gulf water will flood into the Bay). The water will then be pushed WNW and NW by the strong SE winds on the east side of the storm flooding much of Galveston and SE Harris County.

At places such as Clear Lake, the Houston Ship Channel, and Trinity Bay, local funneling effects will produce a higher surge than one would expect along the Gulf beach front of even the rest of the bay. This is due to the surge being funneled into a smaller and narrower passage and forced to rise vertically. A surge of 25.0 ft or greater would be possible at I-45 and Clear Creek with a cat 4/5. A similar 25-30 foot surge would run up the Houston Ship Channel. The surge would run-up to the dam at Lake Houston flooding much of the river and floodplain and runup many of our bayous and creeks until the zero grade was reached.

With that said, there are a few locations within the surge zones that are elevated and would not likely see the extreme surge damage. One thing is for sure...had we taken a direct hit at San Luis Pass from Rita, the western end of Galveston Island would look like Holly Beach, and the communities along the west side of the Bay would be looking like Cameron LA.

We have chose to build in the last 100 years in these vulnerable areas, and luck has been on our side. One day that luck will end and it is going to be a horrible outcome...you would think that those living along the coast would finally understand after the hell of the last 2 hurricane seasons how vulnerable coastal locations are. The "it cannot happen to me" attitude still remains even after Katrina, Rita, Ivan, and Charley.