Katrina is gone

By: Dr. Jeff Masters , 6:56 PM GMT on August 31, 2005

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Katrina lost its tropical characteristics this morning and is no longer a tropical depression, just a regular low presssure system. She continues to dump 2 - 4 inches of rain along her path, and is a threat to bring minor flooding to northern New England today and tomorrow. Katrina-spawned tornadoes killed two in Georgia and damaged 13 homes in Marshall, Virginia yesterday, but the threat of tornadoes has diminished today. Katrina is no more, a blessing we can use right now!

Blessings are very hard to find in the catastrophe zones of Louisiana and Mississippi today. We are only just now beginning to hear from the areas that the calm of the eye passed over. Slidell, on the western side of the eye's passage, received a 15-foot storm surge. Only foundations are left of a large portion of the buildings, and the bridge to New Orleans is broken in multiple places, according to news reports. Pass Christian, unlucky holders of the U.S. record-highest storm surge of 24.7 feet from 1969's Hurricane Camille, received a 20-foot storm surge. The storm surge at nearby Bay St. Louis was 22 feet, and both areas have extensive areas of complete destruction.

Why did the New Orleans flood walls fail?
The 325-mile long series of flood walls and levees surrounding New Orleans were engineered to withstand the storm surge from a Category 3 hurricane. No Category 3 or higher hurricane has hit New Orleans in the past 150 years, a strange quirk one would not expect based on the pattern of hurricane strikes elsewhere along the Gulf Coast. New Orleans should get a Category 3 hurricane passing within 80 miles every 32 years, a Category 4 hurricane every 70 years, and a Category 5 hurricane every 180 years. However, the strongest hurricanes ever to hit the city were two Category 2 hurricanes--a 1893 hurricane that killed 2000, and Hurricane Betsy of 1965, which killed 75 and put parts of the city under 8 feet of water. Hurricane Camille, although it was a Category 5 hurricane and took almost the same track as Katrina, was a very small hurricane with hurricane force winds extending out only about 50 miles from the center. Camille brought 100 mph gusts to the eastern side of New Orleans. Katrina was a huge storm whose hurricane force winds extended a full 110 miles from the center, and probably brought 130 mph wind gusts to the same area. Katrina piled up a much larger storm surge wave onto the flood walls than Camille. According to the Army Corps of Engineers, "What failed were actually floodwalls, not levees. This was caused by overtopping which caused scouring, or an eating away of the earthen support, which then basically undermined the wall. These walls and levees were designed to withstand a fast moving category 3 hurricane. Katrina was a strong 4 at landfall, and conditions exceeded the design." The flood wall breaks lie along Lake Pontchartrain, whose water is 4.5 feet above sea level. Thus, since New Orleans lies 6 feet below sea level, we can expect the city to flood to a depth of at least 10 feet.

I highly recommend reading an October 2001 article from Scientific American, titled: Drowning New Orleans, to learn more about the vulnerabilities of the levee system.

The tropics today
The most significant threat in the tropics I can see is the potential this weekend for a tropical depression to develop in the coastal waters surrounding Florida. This is the same location that Katrina developed. However, this time the development might come at the tail end of a cold front that is expected to push off of the East Coast, instead of from a tropical wave. If a depression does form in this area, the possible track is impossible to guess at this point.

Tropical Depression 13 is nothing to worry about, as it is over the open Atlantic Ocean and heading out to sea. The well-organized wave 1300 miles east of the Lesser Antilles will probably become Tropical Depression 14 in the next day or two, but it is probably too far north to threaten any land areas. This system will probably recurve out to sea. The tropical wave that pushed off of the coast of Africa yesterday and is now south of the Cape Verdes Islands has some potential for development later in the week, and the GFS model projects that this wave will become a hurricane and a potential threat to the Leeward Islands a week or so from now.

On August 19, I posted the image below showing a long-range forecast for August 31 from the GFS model.

As you recall, mid-August was a time of relative quiet in the tropics, but the GFS model was calling for an end to this quiet period. The 12-day GFS forecast called for 3 tropical cyclones for August 31. Well, the GFS was correct in calling for an end to the quiet period! While there is only one tropical cyclone (TD 13) out there, the other two strong tropical waves seen in the satellite image above certainly have the potential to become tropical depressions over the next few days. The GFS did miss the formation of Katrina, but the general 12 day forecast showing a big increase in hurricane activity was pretty accurate.

Dr. Jeff Masters

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193. scrabblechick
9:50 PM GMT on August 31, 2005
I'm just thankful I don't have a long commute to work, and that hubby and I share a small, fuel-efficient car. Wish we could afford a hybrid, but not this year.
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192. o22sail
9:50 PM GMT on August 31, 2005
The governor on WWLTV is telling absolute lies about the days leading up to the storm. Said "didn't know it was coming soon enough."
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191. EllistonVA
9:44 PM GMT on August 31, 2005
The LA governor is blasting the reporters for hounding for body counts. You go girl!
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190. leftyy420
9:51 PM GMT on August 31, 2005
cg, the nhc predicts 2-4more major hurricanes this year.
Member Since: August 24, 2005 Posts: 35 Comments: 1987
189. turtlehurricane
9:48 PM GMT on August 31, 2005
i use the wunderground graphic for sst.
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188. leftyy420
9:50 PM GMT on August 31, 2005
yeah obx. i saw the devestation from isabele up colse and was really shocking. i had damage even at my home when i got back. but that rush during the storm will kepp me chasing as long as ilive. i tell my wife its my way of getting asclose as i can to the power of nature. its crazy but its better than doing drugs or drinking.
Member Since: August 24, 2005 Posts: 35 Comments: 1987
187. cgableshurrycanegal
5:48 PM EDT on August 31, 2005
KS and lefty!!!
No more majors!!! Who cares if the calendar says SEP 1 tomorrow and we still have half the season to go and it's the Cape Verde ::groan:: Season to boot!!!
3 out of 4 hurricanes thus far this season have been major what kind of odds are those???
Member Since: July 12, 2005 Posts: 24 Comments: 214
186. Weatherwatcher007
9:41 PM GMT on August 31, 2005
Don't question my compassion with regards to the situation on the gulf coast, I have family there. As for what I said, no one can jump on me. I am just telling you what I know from years of experience. I never said that FL or the gulf wouldn't get hit again; I just said that I think it won't have another major storm in a while. I think that no one should become complacent and think the season is over because of this storm. You may know that but believe me, there are people I know who think the season is over now. What is going on along the gulf coast is god-awful I know, my thoughts are in the right place. I will do all I can do to find my aunt in NOLA and help the million who are homeless and hunderds or thousands who are dead. It will take years to move on there, another storm would be even worse but. I JUST DON'T KNOW WHAT TO SAY.
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185. leftyy420
9:47 PM GMT on August 31, 2005
here is a linktyo the statements the mayor of nola made today

the other statement i heard was from the head of hurricane research at lsu. he stated they expect 200,000-300,000 didn't evacute and their computer extimates suggest 1/3rd drowned. tahst 40,000-100,000 very shocking statement. he made that statement live on cnn 2hrs ago

Member Since: August 24, 2005 Posts: 35 Comments: 1987
184. OBXER
9:44 PM GMT on August 31, 2005
Lefty i know what you mean i have been here for the past 32 years and the preparation and clean up sucks but the actuall storm is a big rush.Thankfully we havent had anything over a cat 2 in awhile though.
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183. leftyy420
9:46 PM GMT on August 31, 2005
ks, that sounds reasonable.
Member Since: August 24, 2005 Posts: 35 Comments: 1987
182. cgableshurrycanegal
5:43 PM EDT on August 31, 2005
cosmic thanks! 007 a tad out of control. didn't realize an attorney.

lefty, whacko comment ref to storm chasing, I hide under bed!!! ::grin::
Member Since: July 12, 2005 Posts: 24 Comments: 214
181. newinfl
9:42 PM GMT on August 31, 2005
lefty - been working claims geting ready to be deployed to s/ms. I just read your post earlier stating that new estimates for deaths are over 25,000. this is the numbers that we spoke of the night that cat hit and a few were saying were were nuts. Do u have a link or location where I can read that report. I was praying that the number would be low, i knew that it would be in the thousands but prayed for low number. I have not had the opportunity to tell you and others how much I learned for yal and the info that was presented to us. Thanks much.
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180. KShurricane
9:40 PM GMT on August 31, 2005
While we're talking about future storms, anyone want to make predictions for September? I say 7 storms, 4 hurricanes, 2 majors.
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178. Hawkeyewx
4:39 PM CDT on August 31, 2005
the wake left by Katrina is minimal. water is still 90 degrees.


Turtle, Katrina has left a very large pool of cool water in the gulf, barely 80 degrees in spots let alone 90.
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177. cgableshurrycanegal
5:42 PM EDT on August 31, 2005
lefty <~~~ you whacko!!!
Member Since: July 12, 2005 Posts: 24 Comments: 214
176. leftyy420
9:42 PM GMT on August 31, 2005
total, 80 percent of their fuel prices is taxes. when u take away the tax they pay close to what we pay. aslo their economy is setup around their prices. any nation wide spike of 2.oo or more would crush our economy
Member Since: August 24, 2005 Posts: 35 Comments: 1987
175. CosmicEvents
9:37 PM GMT on August 31, 2005
Weatherwatcher.....if you could please refrain for the moment, as hard as that might be for you. I know you're an attorney. The anxiety level is already high enough. No need for alarmist talk on storms that haven't even developed a cloud as yet. Remember you said all the pieces were in place for an Andrew type event in South Florida just a few days ago from Katrina.
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174. raindancer
9:42 PM GMT on August 31, 2005
TotalDestruction... If my math is correct, that equates to about $4 / gallon US. Of course, in Holland, people drive logically sized vehicles - instead of Hummers and Suburbans.
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173. cgableshurrycanegal
5:40 PM EDT on August 31, 2005
Kat has created an agricultural disaster for our local community. Farmers are out close to $500 million. That's not much in the overall scheme of things, but for one county it's a nasty hit.
Member Since: July 12, 2005 Posts: 24 Comments: 214
172. turtlehurricane
9:38 PM GMT on August 31, 2005
its possible the gulf coast will get another storm. its still august afterall. the flood wont be drained until after hurricane season so any storm tide will cause major implications.
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171. leftyy420
9:39 PM GMT on August 31, 2005
obx, thanks man, i willlet u know if we do. not hoping for it but it would be nice to chase another. i chased isabelle, that was my first storm i chased. i told my wife i wouldn't chase any storms south of south carolina, she kinds scared. so i was not able to chase any last year though i wantes to. after ur in one, u can't even watch them on tv with out getting the rush of 100+ wind hitting you
Member Since: August 24, 2005 Posts: 35 Comments: 1987
170. scrabblechick
9:39 PM GMT on August 31, 2005
The wind started to blow really hard here by about 9 p.m. Monday night. By about 1:30 a.m., it was all over, except for some sprinkles and a stiff breeze. That's 360 miles inland. Talk about boogeying....
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169. TotalDestruction
09:38 PM GMT op 31 Augustus, 2005
Gasoline costs in Holland around 1.14 Euro a liter... And that's without disasters... :S
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168. cgableshurrycanegal
5:38 PM EDT on August 31, 2005
turtle, not surprised. Kat was boogeying by then. at 16+ isn't going to create a whole lot of upswelling
Member Since: July 12, 2005 Posts: 24 Comments: 214
167. OBXER
9:36 PM GMT on August 31, 2005
Hey Lefty i hope we dont get one on the east coast but if we do and you chase it down in the outer banks area let me know ive got a motel down here could put you up in.
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166. turtlehurricane
9:35 PM GMT on August 31, 2005
the wake left by Katrina is minimal. water is still 90 degrees.
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165. cgableshurrycanegal
5:33 PM EDT on August 31, 2005
007, I'm sitting here in MIA. You don't think I'm NOT worried about more hurricanes? Think again. I was born and raised in Puerto Rico, long before we had all this sophisticated instrumentation to track systems days out. I now, STILL, live in hurricane country.
I think we can divert a comment or two as well, all so far has been NO-related/KAT related. Don't be a troll.
Member Since: July 12, 2005 Posts: 24 Comments: 214
164. leftyy420
9:33 PM GMT on August 31, 2005
if a storm does hit the east coast i will chase that one and send u guys plenty of pictures, barring i can get gas.
Member Since: August 24, 2005 Posts: 35 Comments: 1987
163. Weatherwatcher007
9:29 PM GMT on August 31, 2005
I'm not that worried about gas right now. What I am worried about is the possiblilty that the main target may of future storms may be the east coast. This not the end of the season I think that anything that moves into the gulf would die in the wake left by Katrina. I think there will be two or maybe three more cat 3 or 4's this year with 2 threatening the east coast.
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162. leftyy420
9:32 PM GMT on August 31, 2005
well iwasn't alive during that but i have heard plenty of stories and with how our contry is now 30 years later things would be much much worse
Member Since: August 24, 2005 Posts: 35 Comments: 1987
161. cgableshurrycanegal
5:29 PM EDT on August 31, 2005
ouch, scrabble, on top of everything else...
I had a car to get from DC to Baltimore to ship to Puerto Rico. We made it off the ship in San Juan and it drove exactly 1/4 mile out of the shipyard and died! Hadn't thought about that in years...
Member Since: July 12, 2005 Posts: 24 Comments: 214
160. cgableshurrycanegal
5:27 PM EDT on August 31, 2005
it was even/odd per your license plate... hmmm... I have a vanity plate with no numbers on it, whatever would they do with me?
Member Since: July 12, 2005 Posts: 24 Comments: 214
159. scrabblechick
9:26 PM GMT on August 31, 2005
I remember, cgables. When my grandfather died in Feb. 1974, he was buried about 65 miles from here. The gas stations were only open on certain days, and we had to promise the funeral home that they would be able to get gas for the hearse, in order for them to transport the body. My cousin, who owned a gas station in the county where the cemetery is, opened up a pump long enough for the hearse and any of the relatives who needed to, to get gas.
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158. Weatherwatcher007
9:26 PM GMT on August 31, 2005
The destruction of New Orleans I mean. Sorry
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157. leftyy420
9:25 PM GMT on August 31, 2005
if any one saw the movie on fx called "oil storm" it was this same stiuation and showed our vunerlbility. this is how it starts. shortages in small pockets that spread. than panic causes people to store more fuel than they need. than winter hits and fuel shortages compound it/ very scary and this is only day 3. 4.99 already very scary
Member Since: August 24, 2005 Posts: 35 Comments: 1987
156. Weatherwatcher007
9:20 PM GMT on August 31, 2005
This is something: New Orleans did not even take a direct hit from a cat 5 and it was nearly wiped off the map. Katrina was a cat 4 and made landfall to the east of NOLA. Should a storm the size of Katrina with the stregnth of Camille (180-200mph) make a DIRECT landfall over NOLA 20-30 years from now, that storm would finish what Katrina started. The total destruction of Katrina. This is the worst storm I have ever seen. My God.
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155. cgableshurrycanegal
5:23 PM EDT on August 31, 2005
anyone else remember the gasoline lines of the 70s?
Member Since: July 12, 2005 Posts: 24 Comments: 214
154. leftyy420
9:22 PM GMT on August 31, 2005
yeah weather i saw that in the models. the first 2 storms, lee, and the eastern wave will recurve. but the wave after that just off the coast now will not be able to and any other waves will folow that waves course across the atlantic. i just hope none get into the gulf
Member Since: August 24, 2005 Posts: 35 Comments: 1987
153. mangroveman
9:06 PM GMT on August 31, 2005
Thanks, Dr. Jeff, for the reference to the Scientific American article from 2001 predicting the impacts of a storm like Katrina. It comes as no great surprise. Nor does the lack of willpower on the part of Bush's pathetic attempt at government to do anything with the report.
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152. turtlehurricane
9:21 PM GMT on August 31, 2005
in that case the french quarter is gone. they could get a firefighter helicopter if they wanted to though.
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151. cgableshurrycanegal
5:22 PM EDT on August 31, 2005
just think about the history we're losing right now in NO. It's one of our oldest, continually occupied cities in North America. A rich history, not just Mardi Gras...
Member Since: July 12, 2005 Posts: 24 Comments: 214
150. leftyy420
9:20 PM GMT on August 31, 2005
yeah scrabble i wasn't saying that to you i was just stating that i don't think no one outside the affected area really knows what is going on. like bush today. u could see he now realises the scope of this, and i think he looked alittle shocked
Member Since: August 24, 2005 Posts: 35 Comments: 1987
148. leftyy420
9:18 PM GMT on August 31, 2005
well bush just said they will realse oil from the reserve but there atleast 3 refineries still underwater. some others have damage and need to be fixed. others have no crew to man them as they evacuated and now have no hometo come back to. this will be a painfull few months and maybe a painfull year
Member Since: August 24, 2005 Posts: 35 Comments: 1987
147. cgableshurrycanegal
5:17 PM EDT on August 31, 2005
turtle, these fires will spread building to building and the FD can't do a thing about it. Particularly in the older sections of town where buildings are extremely close together and have alot of wood structures. It could go very fast. So what if it's to the water line? It's still gone. Remember the newspaper building in Indianapolis (?) that they watched burn in the middle of a flood just a few years back?
Member Since: July 12, 2005 Posts: 24 Comments: 214
146. turtlehurricane
9:17 PM GMT on August 31, 2005
the french quarter structures will start failing in a few days anyways from water. this is just so sad.
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145. scrabblechick
9:18 PM GMT on August 31, 2005
Not disputing anyone--just passing along what the official sources are saying. I'm not offering an opinion on what they're saying, one way or the other--just posting information.
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144. 147257
09:19 PM GMT op 31 Augustus, 2005
lee is generated
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143. Weatherwatcher007
9:14 PM GMT on August 31, 2005
I think the gulf coast is done for the year, if not at least for now. I think the next storms will come close or hit the east coast. Some models predict a very strong high pressure ridge in the next 144 hours that would eliminate any storm from recurving in the atlantic. This is unreal, this isn't even the peak of the seasons and some of the strongest storms formed in september.
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Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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