Postcards IV: Katrina's storm surge, and the Rita evacuation

By: Dr. Jeff Masters , 9:03 PM GMT on May 01, 2008

Share this Blog
2
+

I'm in Orlando this week for the 28th Conference on Hurricanes and Tropical Meteorology, sponsored by the American Meteorological Society. The conference, held once every two years, brings together the world's experts on hurricane science. Two postcards from today's talks:

Hurricane Rita evacuation survey
The evacuation effort for Hurricane Rita as it approached the Texas/Louisiana coast was one of the largest evacuation efforts of all time. Rebecca Mouss of the National Center for Atmospheric Research reported on the results of a survey of 120 residents of Houston, Galveston, and Port Arthur, Texas that evacuated from Rita. Since Rita came so soon after Hurricane Katrina's record devastation, 55% of the people surveyed reported that Katrina influenced their decision to evacuate, and 10% said it was their primary reason for evacuating. For future storms, a majority of the people said they would evacuate if evacuation orders were given for a Category 3 hurricane, but not for a weaker storm. Five percent said they would not evacuate ever, even for a Category 5 hurricane.


Figure 1. Hurricane Rita bears down on the Texas/Louisiana coast.

Katrina's storm surge
Pat Fitzpatrick of Mississippi State University studied the effect of the levee system along the Mississippi River on Hurricane Katrina's storm surge. Katrina had the highest storm surge on record in the Atlantic--an astonishing 27.8 feet along the Mississippi coast. Fitzpatrick showed that the levees along the Mississippi River acted to dam up the storm surge along the east side of the Mississippi River, increasing the storm surge by 2-3 feet within 15 miles of the levees. Calculations from a storm surge model showed that inundation of Chalmette and the Ninth Ward of New Orleans was accelerated by 1-5 hours, thanks to the presence of the levees, with a higher surge of 3-7 feet. In contrast, the levees had little impact on the timing or height of the surge on the Mississippi coast. It is possible that, without the river levees, hard-hit Chalmette and the 9th Ward may have experienced significantly less flooding.

Fitzpatrick also modeled the effect of the loss of wetlands due to erosion on Katrina's storm surge. The general rule of thumb developed for work in the 1960's credited wetlands with reducing storm surge by one foot for every 2.7 miles the storm surge had to pass over a wetland. The SLOSH storm surge model found that wetlands in Louisiana were actually twice as effective in reducing storm surge--each three miles of wetland the surge passed over reduced Katrina's storm surge by two feet. Note that this effect varied with the depth of the surge--an eight foot high surge was knocked down about 13% by wetlands, while a one foot high surge was reduced 59%.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 257 - 207

Page: 1 | 2 | 3 | 4 | 5 | 6Blog Index

257. Sophmom
9:24 PM GMT on May 02, 2008
Pat, I hadn't thought to check the River Cam. Duh! Thanks!
256. Patrap
8:38 PM GMT on May 02, 2008
A Good View Of Algiers Point right Now Sophmom..Storms for Jazz Fest today. Link
Member Since: July 3, 2005 Posts: 426 Comments: 129093
255. Stormchaser2007
8:34 PM GMT on May 02, 2008
I can see why that theres a "EXTREMELY LARGE" tornado with this. Check out the hook with this.
Link
Member Since: June 9, 2007 Posts: 4 Comments: 15946
254. Sophmom
8:34 PM GMT on May 02, 2008
Pat, you picked a great day to go to Jazzfest last Friday, both from a weather as well as a talent perspective. We got wet Saturday but had a great time anyway. I guess we'll go Sunday this weekend?

I did go to the Fly last Sunday to see the river. I'd been here for 3 weeks and hadn't seen it yet. Yup. It was full. :)
253. Patrap
8:30 PM GMT on May 02, 2008
Dupage Severe Weather Warnings Page Link
Member Since: July 3, 2005 Posts: 426 Comments: 129093
252. Patrap
8:29 PM GMT on May 02, 2008
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MEMPHIS TN
320 PM CDT FRI MAY 2 2008

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 345 PM CDT FOR
NORTHWESTERN CRITTENDEN...NORTHEASTERN ST. FRANCIS AND SOUTHEASTERN
CROSS COUNTIES...

AT 320 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR AND STORM
SPOTTERS WERE TRACKING AN EXTREMELY LARGE AND DANGEROUS TORNADO
TRACKING ACROSS EASTERN CROSS MOVING QUIKLY INTO CRITTENDEN COUNTY.
THIS TORNADO WAS LOCATED NEAR PARKIN...MOVING NORTHEAST AT 40 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
JENNETTE...EARLE AND CRAWFORDSVILLE.

.IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING
GOLFBALL SIZE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.

NEXRAD Radar
Memphis Base Reflectivity 0.50 Degree Elevation Range 124 NMI Link
Member Since: July 3, 2005 Posts: 426 Comments: 129093
251. Cavin Rawlins
8:10 PM GMT on May 02, 2008
I'm not really anticipating development. This is more of a sample wave for me. Comparing early season waves with those at the peak of the African Easterly Wave Season.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
250. CaneAddict
7:59 PM GMT on May 02, 2008
246. Drakoen 7:47 PM GMT on May 02, 2008
I don't think this wave will get remotely close to invest status. It is very impressive for this time of year but shear will increase over the system especially as it moves slowly to the west.


If it takes great advantage tonight during the night hours or dirunal max, An invest is not out of the question. I do agree though, Not much will come of it.
Member Since: October 5, 2007 Posts: 3 Comments: 2151
249. koneofdeath
7:55 PM GMT on May 02, 2008
SOMEONE said tropical wave?
Member Since: June 15, 2007 Posts: 0 Comments: 35
248. Cavin Rawlins
7:53 PM GMT on May 02, 2008
yeah cane...its the first official but the link says first of...we already had a few that I still believe was AEWs. But I think part of the definition of waves the TPC uses is the time of year (May to December).
Member Since: July 24, 2005 Posts: 407 Comments: 19076
247. morningmisty
7:53 PM GMT on May 02, 2008
Hello to all of you, I have learned alot about hurricanes and other storms from your site, but I must say that Tampa did have some damage in 2004. I do not know if there were hurricane strength winds, but I had to evacuate 4 times that season. Charlie did not directly hit us, but we were near a tornado on the way back home. Southern FL and Orlando suffered more than we did. The worst damage was following Frances when a tree hit a home next to ours and we were without power for aa week.
I enjoy looking at the storms and reading all your comments, but I hope we don't have too many powerful hurricanes. It seems like we might be in for an active season though.

Member Since: September 29, 2007 Posts: 0 Comments: 13
246. Drakoen
7:47 PM GMT on May 02, 2008
I don't think this wave will get remotely close to invest status. It is very impressive for this time of year but shear will increase over the system especially as it moves slowly to the west.
Member Since: October 28, 2006 Posts: 57 Comments: 30615
245. CaneAddict
7:39 PM GMT on May 02, 2008
211. TBWX3000 6:33 PM GMT on May 02, 2008
Yes that is true. We did feel gails during Charley though in 2003.


Charley as in 2004 not 2003....

And our wave will likely be labeled invest 90L tomorrow if it persists. Shortly after that though, It will encounter unfavorable conditions.
Member Since: October 5, 2007 Posts: 3 Comments: 2151
244. FallenStar
7:38 PM GMT on May 02, 2008
Went thru Elena On Pass Road not far from the SeaBee Base in 85,..Welcome to the Blogs.

Ooh, Pass Road is quite a bit further north from me. I was down on the southern side of Government Blvd during Elena (south of 90) over in OS.

I don't remember much of Elena, though I do remember we were cloistered in the hallway and that I got ill (throwing up and such) during the hurricane. I don't know whether it was then that the street outside flooded or not, but I definitely remember people going by in rowboats once, though the house itself wasn't flooded, lol.
243. Drakoen
7:35 PM GMT on May 02, 2008
I see we have our first official tropical wave. Very well defined inverted signature with some relative vorticity on the poleward end of the wave axis.
Member Since: October 28, 2006 Posts: 57 Comments: 30615
242. CaneAddict
7:30 PM GMT on May 02, 2008
241. Weather456 7:22 PM GMT on May 02, 2008
First Wave of 08


You may want to change that to the First REAL wave. We already had one tropical wave, Although barely, That the NHC confirmed on April 9th i believe.
Member Since: October 5, 2007 Posts: 3 Comments: 2151
241. Cavin Rawlins
7:22 PM GMT on May 02, 2008
First Wave of 08
Member Since: July 24, 2005 Posts: 407 Comments: 19076
240. pearlandaggie
7:22 PM GMT on May 02, 2008
interesting article on NASA "reworking" climate data:

Is the earth getting warmer, or cooler?


Member Since: September 14, 2007 Posts: 3 Comments: 3963
239. Stormchaser2007
7:21 PM GMT on May 02, 2008
LOL Gulf!!!!
Member Since: June 9, 2007 Posts: 4 Comments: 15946
237. Stormchaser2007
7:13 PM GMT on May 02, 2008
Well here it is....
Member Since: June 9, 2007 Posts: 4 Comments: 15946
236. Stormchaser2007
7:10 PM GMT on May 02, 2008
Way too early....but sheer is already starting to interact with blob/wave

Yeah it is way to early these thing usually roll off by Late July early august. Actually the shear is only 5nts above this thing.
Member Since: June 9, 2007 Posts: 4 Comments: 15946
235. southbeachdude
7:07 PM GMT on May 02, 2008
Way too early....but sheer is already starting to interact with blob/wave
Member Since: July 29, 2005 Posts: 2 Comments: 697
232. NEwxguy
6:59 PM GMT on May 02, 2008
If you will it,90L will come
Member Since: September 6, 2007 Posts: 886 Comments: 15950
231. hurricane23
6:56 PM GMT on May 02, 2008
Nothing even close to a LLC showing on quikscat.
Member Since: May 14, 2006 Posts: 8 Comments: 13839
228. Cavin Rawlins
6:53 PM GMT on May 02, 2008
We'll have wait and see what happens either near 30W or 48 hrs time. Right its the first wave that will analysed on surface maps. Last year it was around the last 10 days in May.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
227. Tazmanian
6:52 PM GMT on May 02, 2008
whats wind shear like in front of it for the next few days????
Member Since: May 21, 2006 Posts: 5091 Comments: 115362
226. weatherboyfsu
6:53 PM GMT on May 02, 2008
Good afternoon,

Arkansas and the surrounding states sure are taking a beating. Hope there was lots of warning and prayers!
Member Since: July 17, 2005 Posts: 0 Comments: 1025
224. hurricane23
6:49 PM GMT on May 02, 2008
Its a wave alright but it will run into lots of trouble real soon.
Member Since: May 14, 2006 Posts: 8 Comments: 13839
223. Patrap
6:48 PM GMT on May 02, 2008
The Tornado Continues on the Ground here..

NEXRAD Radar
Memphis Base Reflectivity 0.50 Degree Elevation Range 124 NMI Link
Member Since: July 3, 2005 Posts: 426 Comments: 129093
222. Tazmanian
6:48 PM GMT on May 02, 2008
looks like we may have 90L soon
Member Since: May 21, 2006 Posts: 5091 Comments: 115362
221. Cavin Rawlins
6:47 PM GMT on May 02, 2008
It has been a wave all day...Excellent inverted V pattern



Member Since: July 24, 2005 Posts: 407 Comments: 19076
219. hurricane23
6:45 PM GMT on May 02, 2008
Shear is only around 5kts lol.A bit early for this stuff!

You will see the wave added to this map at 18z.
Member Since: May 14, 2006 Posts: 8 Comments: 13839
217. Patrap
6:42 PM GMT on May 02, 2008
Dr.Masters was referring to the River Levees.One has to Have them..or every Spring like this year, flooding could occur like in the Upper Miss River Valley,below Baton Rouge.
Without the Spillway opening, the velocities along the River threatens the Levees. Its a passe thing to say the Miss River Levees caused any Surge Heights to be Higher. The River Levee's been there nearly 90 years.

Member Since: July 3, 2005 Posts: 426 Comments: 129093
216. Cavin Rawlins
6:41 PM GMT on May 02, 2008
Good a tropical wave as suspected.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
215. hurricane23
6:39 PM GMT on May 02, 2008
LOL well here you go TROPICAL WAVE will officially be introduced on the 18z map.

THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 2N10W 2N20W EQUATOR AT 34W THEN
1N43W INTO NE BRAZIL. CLUSTERS OF MODERATE/ISOLATED STRONG
CONVECTION COVER THE AREA FROM 3N TO 9N EAST OF 20W TO THE
AFRICAN COAST. A SFC TROUGH WAS ANALYZED IN THIS AREA ALONG
15W/16W ON THE 12Z SFC MAP. THERE SEEMS TO BE ENOUGH EVIDENCE TO
SUGGEST THAT THIS COULD BE A TROPICAL WAVE. SATELLITE IMAGERY
SHOWS A WELL DEFINED INVERTED V-PATTERN. THE HOVMOLLER DIAGRAM
ALSO INDICATES THE WWD PROPAGATION OF THIS SYSTEM DURING LAST
TWO DAYS...AND THE BAMAKO SOUNDING SHOWED THE PASSAGE OF THIS
TROUGH/WAVE BETWEEN APRIL 30 AND MAY 1ST. BASED ON THIS DATA AND
THE TIME OF THE YEAR


Here are several views of the african coast which ive always used for tropical waves of the african coast.

1st link and 2nd link

More tropical links can be found HERE on my tropics page.

HERE is another one from LSU

Besides the links i provided you can always get more from SSD.
Member Since: May 14, 2006 Posts: 8 Comments: 13839
214. Patrap
6:37 PM GMT on May 02, 2008
Went thru Elena On Pass Road not far from the SeaBee Base in 85,..Welcome to the Blogs.
Member Since: July 3, 2005 Posts: 426 Comments: 129093
213. DocBen
6:36 PM GMT on May 02, 2008
Interesting that the levees seem to have made the storm surge WORSE instead of better. Maybe we would be better off with nature instead of the Army Corps of Engineers.
Member Since: May 16, 2006 Posts: 0 Comments: 98
212. FallenStar
6:34 PM GMT on May 02, 2008
Hi, all! I'm FallenStar. My buddy, Koritheman wanted me to join since I have personal experience (and, thus, a great interest), in hurricanes and the like. lol

I live on the coast of MS, not more than a mile or two away from the coast, yet, I have not yet been flooded out from any hurricane, whether it be Elena in '85, Georges in '98, Ivan in '04, and the four-way punch of Cindy, Dennis, Katrina, and Rita in '05.

I'm not saying it won't ever happen, though. Just merely that it hasn't happened and for that, I can only feel grateful, lol.

One thing that always interested me was how *did* Ivan make that complete circle? Was it circulating an upper level high(or low)?

And, what exactly made Katrina make that more southwesterly turn? I theorized that it was an upper level high that moved back over the U.S. when it wasn't thought to be doing so.

Thanks for any and all information! =D
210. CaneAddict
6:32 PM GMT on May 02, 2008
....so west texas and TAMPA are pretty much the only areas along the Gulf that have not experienced Hurricane force winds in recent history. (1995).... does this give us here in central west fl a larger probability of getting hit every year??? It's a scary idea....

Not neccessarily...Tampa has not had a DIRECT hit for like over a Century...i believe.
Member Since: October 5, 2007 Posts: 3 Comments: 2151
209. CaneAddict
6:30 PM GMT on May 02, 2008
I dont think that our feature has associated low-level turning, More like the mid-levels...
Member Since: October 5, 2007 Posts: 3 Comments: 2151
208. FLWeatherFreak91
6:29 PM GMT on May 02, 2008
I've been thinking about this over the past few months and I have realized that Tampa is pretty much the only city along the gulf that has been spared by hurricane force winds for a long time now (I'll start at 1995). I have put together a list of the Gulf coast cities and the hurricane which affected each most recently.

We'll start from the West:
*Corpus Christi for the most part has been spared from hurricane winds
*Like CC, Houston has sustained little damage from hurricanes although a number of TS have come through including Grace and Dean
*Beaumont was just affected lat year as Humberto rapidly formed and moved through bringing hurricane force winds.
*The entire coast of LA, as we all know, was affected by strong hurricane force winds as Rita and Katrina came through.
*Mississippi was affected with strong Hurricane force winds with katrina as well.
*Pensacola was covered with the hurricane winds by Ivan in '04 along with most of the FL peninsula
*The west coast of Fl north of new port Richey experienced hurricane force gusts as Frances and Jeanne blew by.
*TAMPA has not been affected by hurricane force winds or even gusts during this whole time
*SW fl was hit recently by Charley and Wilma
*The keys got Georges in '98 and wilma in "05
SE fl got Wilma, Frances, and Jeanne as did CE Fl
*Jax has been spared for the most part although they did experience minimal hurricane force gusts when Charley crossed the state.

....so west texas and TAMPA are pretty much the only areas along the Gulf that have not experienced Hurricane force winds in recent history. (1995).... does this give us here in central west fl a larger probability of getting hit every year??? It's a scary idea....
Member Since: December 1, 2006 Posts: 2 Comments: 3631
207. newt3d
6:28 PM GMT on May 02, 2008
The shape of the coast of Myanmar combined with the direction of that landfalling storm and the winds associated with it look particularly bad for storm surge concerns. It looks like the winds will just be shoving the water into a v-shaped cone for several hours.
Member Since: October 6, 2005 Posts: 0 Comments: 90

Viewing: 257 - 207

Page: 1 | 2 | 3 | 4 | 5 | 6Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.