Rita: Category 5, still intensifying

By: Dr. Jeff Masters , 5:42 PM GMT on September 21, 2005

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The 3:37 pm eye report from the hurricane hunters found a 914 mb pressure and flight level winds of 161 knots (186 mph). These numbers plus the satellite intensity estimates support upgrading Rita to a Category 5 hurricane. Tonight, Rita will be passing over the Loop Current, a warm eddy of water in the Gulf that aided Katrina's growth to a Category 5 hurricane. Fueled by this pool of deep warm water and an almost ideal upper level wind environment, Rita should continue to intensify until Thursday morning, when she will pass beyond the Loop Current. The eye has started to shrink as Rita continues to intensify, and is down to 20 nm diameter from 25 nm earlier this afternoon. By the time the eye shrinks down to 10 nm, the eyewall will collapse and an eyewall replacement cycle begin, putting an end to this intensification cycle. With another 12 hours to go before this happens, Rita could approach historic intensity, and is already one of the ten strongest Atlantic hurricanes on record.

The list of strongest hurricanes of all time reads:

Hurricane Gilbert (888 mb, 1988)

The Great Labor Day Hurricane (892 mb, 1935)

Hurricane Allen (899 mb, 1980)

Hurricane Katrina (902 mb, 2005)

Hurricane Camille (905 mb, 1969)

How low will Rita go?

I'll post the rest of my discussion from this morning below:


It's been a long time since Texas had a severe hurricane. Hurricane Bret hit the state in 1999 as a Category 4 hurricane, but was small and hit the relatively unpopulated Padre Island National Seashore. Bret gave Texas the unique distinction of being the only state to get hit by a Category 4 hurricane that didn't get its name retired. In 1988, Hurricane Gilbert, the strongest hurricane of all time, just missed Texas, hitting south of the border. The last hurricane to do serious damage to Texas was Hurricane Alica of 1983, which hit Galveston as a weak Category 3 storm, pushing a 10 - 12 foot storm surge into Galveston Bay. Alica killed 21 people, and its $2 billion price tag was the highest in Texas hurricane history.

Texas's luck is about to change. Rita, looking more and more like a nightmare copy of Katrina somehow displaced in time, will make sure of that. The forecast models we so heavily rely on did not anticipate another Katrina-like storm when Rita first formed and plowed through the Florida Straits. But now, the forecasts mirror the reality unfolding today in the Gulf of Mexico. Rita will be another huge destructive hurricane for the Gulf Coast. This time, it is Texas's turn. Every other state on the Gulf Coast has borne the burden of the immense destruction created by our unprecedented onslaught of intense hurricanes the past two hurricane seasons. No state will be left out.

Rita's impact on the Florida Keys
The residents of the Keys returning to their homes today are the lucky ones, for the Keys escaped serious damage. A 4 - 6 foot storm surge did hit the Lower Keys and flood the Coastal Highway, but this quickly subsided and the highway is now open to traffic again. Some minor to moderate wind damage occurred, but winds in Marathon only reached 38 mph, gusting to 53 mph, while the winds at Key West Airport reached 56 mph, gusting to 73 mph. There was an unofficial report of sustained winds of 75 mph gusting to 102 mph in Key West. Rainfall amounts of up to 12 inches occurred in the Keys, causing minor flooding problems.


Figure 1. Estimated rainfall from Hurricane Rita.


Figure 2. Wind and pressure plot from a coastal weather station in the Lower Keys. Note how the pressure after Rita's passage remains lower than that before her passage--Rita has depressed pressure values over an area hundreds of miles wide.

Rita now
Rita's presentation on satellite imagery is classic; she has a well-formed eye, large Central Dense Overcast (CDO) of cirrus clouds surrounding the eye, and well developed outflow on all sides, particularly to the north. Rita is currently smaller than Katrina, though. Katrina at her peak had hurricane force winds that extended outward 120 miles from the center; Rita's hurricane force winds only extend out 70 miles from the center. This will change as Rita continues to intensify and expand in size over the next day or two. There is little shear over Rita at present, nor is there expected to be the next three days. Water temperatures are 1 - 2C cooler over the central Gulf than they were for Katrina, which may keep Rita from attaining quite the intensity Katrina did. However, once Rita crosses the Gulf and arrives in the western Gulf on Friday, water temperatures warm back up to 30 - 31C, about the same temperatures as the waters Katrina had to work with.

Rita at landfall
Rita's future intensity will largely be controlled by impossible-to-predict eyewall replacement cycles. Rita is growing large enough that she is creating her own upper level environment that will be relatively impervious to any external shearing winds that try to weaken her. I expect Rita to be a Category 4 hurricane at landfall.

The landfall location forecast has increased in confidence since yesterday, as the computer models have started to converge on a landfall location on the middle Texas coast. Western Louisiana still needs to be concerned, as does Corpus Christi, but New Orleans should escape Rita with nothing more than some fairly ordinary thunderstorms in some of the outermost spiral bands. A significant storm surge capable of flooding New Orleans is very unlikely.

A very significant storm surge is expected along and to the right of where Rita makes landfall on the Texas coast. Surge heights may reach 25 feet or higher, breaking the record 22 foot storm surge seen in 1961 during the Category 4 Hurricane Carla.

Elsewhere in the tropics
Tropical Storm Philippe continues northward away from land, and is not not expected to be a threat. Strong shearing winds will likely tear Philippe apart by Saturday. The remainder of the tropics are quiet and expected to remain so through Friday. By Saturday, the chances of tropical storm development off the coast of Africa begin to increase.

Jeff Masters

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1107. pbaylis
10:08 AM GMT on September 22, 2005
Interesting about God's possible intervention. I join those praying for a reprieve for those pour souls in the impact zone.

Interesting link I stumbled across not so long ago. There's a prophecy there relating to Satan's control of storms.

From: http://www.ladyofroses.org/warning.htm
Our Blessed Mother Mary's alleged message to an American mystic quite recently:
"In My counsels of the past, My children, I have told you many times that satan has control of the elements. There will be accidents that are not accidents, disturbances of nature claiming many lives: floods, tornadoes
1106. cajunkid
2:43 AM GMT on September 22, 2005
I 'm sorry but you are a dumbass if you stay in Galveston. I can't believe there are people who won't get the hell out. Lefty, do you know how to post those pictures of Buras LA that I sent you? I wish I could show those to the people who think they can ride this one out.
Member Since: July 10, 2005 Posts: 3 Comments: 1281
1105. cajunkid
2:39 AM GMT on September 22, 2005
Link
Member Since: July 10, 2005 Posts: 3 Comments: 1281
1104. code1
2:05 AM GMT on September 22, 2005
It is starting to get late, and many of us will soon go bed,the grotto must have worked in the Key's.....let's all say a prayer for those to be affected even as we are fascinated with the phenom.
Member Since: September 18, 2005 Posts: 66 Comments: 13872
1103. muffinanne
1:36 AM GMT on September 22, 2005
Having been on a flight in South America that was close to crash on landing and aborted landing and then came back in to land successfully, I can say that these people have been traumatized over that last several hours. They may look calm as they are leaving the plane right now, but like myself, I went into the ladies bathroom and wept for a while before my first of many cocktails that evening.
1102. dracko19
1:32 AM GMT on September 22, 2005
OMG! THE MODELS SHIFTED EAST! GROUND ZERO IS NOW HOUSTON!!!

http://maps.wunderground.com/tropical/tracking/at200518_model.html
Member Since: September 21, 2005 Posts: 2 Comments: 310
1101. GRDRATNAVARRE
1:30 AM GMT on September 22, 2005
MUFFIN -- I stand corrected, and glad of it.
1100. WillJax
1:28 AM GMT on September 22, 2005
Sweeeeet landing, those pilots deserve a free vacation! Those passengers deserve a free vacation! Vacations for all!
Member Since: September 7, 2005 Posts: 0 Comments: 33
1099. iyou
1:28 AM GMT on September 22, 2005
OldWorld-GlobalWeatherSystem - I wish you were not so elusive!
Member Since: July 25, 2005 Posts: 0 Comments: 5219
1098. Thermohalineeotw
1:25 AM GMT on September 22, 2005
WOW Awesome Landing !

What an absolutely fantastic pilot!
Textbook, could not have been better.
1097. muffinanne
1:22 AM GMT on September 22, 2005
It's down, and was nothing close to a "crash". Thank the LORD!!!!!!!!!!!!!!!!!!!!
1096. GRDRATNAVARRE
1:20 AM GMT on September 22, 2005
wow!!!!! those gear held, i am amazed. THANK GOD!!!
1095. Valence
1:20 AM GMT on September 22, 2005
SOMEONE BUY THIS PILOT A BEER!

(Hopefully not before his next flight!)

JV
1094. Valence
1:19 AM GMT on September 22, 2005
ftlaud-

The EWRC is not really a decrease in intensity. All it means is that the inner core cannot sustain the intesnsity, so it breaks down. When the outer eyewall closes and shrinks after the EWRC, the hurricane is stronger. During the EWRC, the hurricane loses intensity, which is why you hope for one as a hurricane makes landfall.

However, unless Rita's eye starts to shrink, she will probably not have an EWRC. Rita is an annualar (or doughnut) hurricane. These types of canes have a larger eyewall, and no real feader bands (hence the doughnut nickname) Katrina was an annular hurricane, and never underwent an EWRC from the time she was a cat 3.

So yes, an annular hurricane is must more capable of sustaining a higher intensity, and is less likey to undergo a dramatic detensification during landfall.

JV
1093. muffinanne
1:15 AM GMT on September 22, 2005
This is going to be a successful emergency landing!!!!! Hope, hope, hope. Not a crash.
1092. OldWorld
1:10 AM GMT on September 22, 2005
HUHhricane?

Not good enough.

Yours truly,
Your GlobalWeatherSystem
1091. WillJax
1:09 AM GMT on September 22, 2005
Nah, plane is way too heavy to not go straight because of a little nose gear problem. It's momentum will track it stright down the center line.

Great, stupid ass satellite just went out b/c of storms. This should be a cable commercial!
Member Since: September 7, 2005 Posts: 0 Comments: 33
1090. pseabury
1:08 AM GMT on September 22, 2005
Looks like eyewitness reports of the tornado have slowed/stopped.....warning expiring but still hail and winds.

Member Since: May 28, 2005 Posts: 0 Comments: 3
1089. amd
1:07 AM GMT on September 22, 2005
i think this hurricane will undergo an EWRC in the next 12 hours, but after that, I think that will be the last EWRC because annular hurricanes do undergo many EWRC's.

The 100 billion dollar question (note that I chosed that value on purpose) is that will this storm be able to ramp back up to near or at its current levels before landfall.

I think bastardi nailed this storm when he said that this storm will be the strongest hurricane to ever hit texas, and it may be the strongest by a significant margin.

Member Since: August 29, 2005 Posts: 0 Comments: 1024
1088. pseabury
1:05 AM GMT on September 22, 2005
WILLJAX - depends if the front gear forces the nose laterally before it collapses or shears off. I guess we'll see.....say a prayer.
Member Since: May 28, 2005 Posts: 0 Comments: 3
1087. WillJax
1:02 AM GMT on September 22, 2005
Any word on the Tornado?

I'm thinking this landing should be okay... the rear gear is fine, which will allow the plane to track straight once it hits ground. More importantly it will keep the wings from hitting the ground.

Member Since: September 7, 2005 Posts: 0 Comments: 33
1086. Valence
1:00 AM GMT on September 22, 2005
StSimmons-

Gilbert did not make a landfall with a sub 900 pressure. Im sure part of the reason that the pressure came back up was because of the interaction with land, but it was only a cat 4 when it officially made landfall.
1085. FLexpatriate
12:58 AM GMT on September 22, 2005
Annular hurricanes like Kat and, now, Rita tend to go through less EWRCs than other types of intense hurricanes. The "stadium" effect tends to stabilize the eye and keeps it from collapsing inward on itself.

As long as Rita is in a favorable environment for strengthening, she probably won't undergo an EWRC, which means she'll continue to deepen.
1084. SaCaCh
12:57 AM GMT on September 22, 2005
Masters has just posted again calling for a stall over TX this is unbelievable news....!!
1083. fortlauderdalegirl
12:57 AM GMT on September 22, 2005
Valence: So, given that, if Rita continues to intensify and does not go thru an EWRC, the chances of a DECREASE in intensity are much less -- Am I on track?? Please clarify.
1082. muffinanne
12:57 AM GMT on September 22, 2005
Just a few minutes from the landing. It's going to be OKAY!!!
1080. Valence
12:54 AM GMT on September 22, 2005
ftlauderdale-

Katrina never really went through an eyewall replacement cycle. The general thinking has always been that as major hurricane intensifies, the eye conctacts due to the drop in pressure and increase in wind (centrifugal force), At a diameter of about 10-12nm for a cat 4 or 5 storm, the system becomes unstable and the eyewall begins to breakdown, and the outer eyewall takes over.

Right now, Rita's eye is 20nm wide, and not really getting smaller. Unless that eye starts to shrink, or the system becomes unstalbe for another reason, there is no reason for the EWRC to begin.

JV
1079. pseabury
12:54 AM GMT on September 22, 2005
Latest A98E puts Rita Just West of Cocodrie, LA. A98E always seems to flip out...although it was in decent agreement with the rest of the models until now.

Member Since: May 28, 2005 Posts: 0 Comments: 3
1078. leftyy420
12:53 AM GMT on September 22, 2005
be bck in a bit. going to go eat and what not
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1077. leftyy420
12:51 AM GMT on September 22, 2005
no she doesn't. as long as that eye stays bigger than 7-10nm she will not have to undergo a ewrc. its the fprce of an eye that small that casues the ewrc. i dobut she will go with out one but nothing says she must do it. katrina only when thru one and that was befor she was a cat 5.
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1075. Valence
12:49 AM GMT on September 22, 2005
Gilbert went from a pressure of 960 to its record of 888 in only 24 hours.

Thats a drop of 72mb, or about 3 per hour.

Right now, Rita has gone from 973 to 898 in about 27 hours. So, do the math...thats a little less than 3mb per hour.

JV
1074. fortlauderdalegirl
12:48 AM GMT on September 22, 2005
Lefty -- Does a hurricane HAVE to enter a EWRC?? It it possible that Rita can go along w/o it??
1073. Weather89
12:45 AM GMT on September 22, 2005
StSimons, the way she has been deepening there is a very distinct probably she could break the 24 hour record held by Gilbert. It is also very unusual that it hasnt already undergone an EWRC after such strengthening. I suspect that it will be at least another 10 hours or so before she would enter one... which means she will probably continue to strengthen under the warm SST's of the central Gulf. This storm is impressive!
1072. SportingWood
12:45 AM GMT on September 22, 2005
OldWorld: How true... Nature only seeks to survive and flourish, and it's not just organic life.
1071. FLexpatriate
12:45 AM GMT on September 22, 2005
OldWorld, HUH???

Watching footage of this attempted landing of this JetBlue airliner... fascinating
1070. OldWorld
12:40 AM GMT on September 22, 2005
The existence of EllistonVA is not known to me.
No names are known to me.
I am an energetic system which seeks homeostasis.
If disrupted, I strenuously seek balance.
If corrupted, then pathological symptoms will ensue.

Please...It's not personal...I'm only trying to survive.

Yours truly,
Your GlobalWeatherSystem
1069. stevego
12:40 AM GMT on September 22, 2005
I am in western wisconsin watching all of this tonight...its the most excitment i have had in awhile..radar images up in one window cnn on the tv and the hurricane blog in the other window
Member Since: August 31, 2005 Posts: 0 Comments: 0
1067. leftyy420
12:37 AM GMT on September 22, 2005
yeah 89. me either
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1066. Weather89
12:35 AM GMT on September 22, 2005
thanks lefty for clarifying. I am in just total shock of the amazing intensification the storm has undergone in the last 30 hours or so. I don't remember any hurricane in the Atlantic that's central min. pressure has dropped as fast as rita!!! This is one impressive storm!
1065. fortlauderdalegirl
12:35 AM GMT on September 22, 2005
Valence -- LOL lots! Sad, but true lately! My guess is a earthquake could be the next thing.
1064. muffinanne
12:34 AM GMT on September 22, 2005
GRD -- we all are hopingand praying right now. Thanks for your input,
1063. leftyy420
12:33 AM GMT on September 22, 2005
carbo, there is nothing toslowher down. there is also no evedince she will ever undergo an eye wall cycle. isabeal was a cat 5 for 2.5 days.so right now until that eye comes back smaller on recon and the pressure keeps dropping atleast 1 mb and hr she is still getting deeprand stronger
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1062. Valence
12:32 AM GMT on September 22, 2005
Rita's pressure drops Below 900mb!

Jet Blue Plane trying to land at LAX with its front landing gear turned SIDEWAYS! (how the hell does that happen anyway?)

Tornado touching down in Minneapolis!

Im waiting for the cloud of locusts to come flying by my window. . .

JV
1061. GRDRATNAVARRE
12:31 AM GMT on September 22, 2005
muffin -- i'm hoping for the best, crash was a rash statement on my part, but it's a crash landing if that makes it better.
1060. Weather89
12:31 AM GMT on September 22, 2005
ok, thanks carbo. I was just trying to think a little optimistically.
1059. leftyy420
12:30 AM GMT on September 22, 2005
weather that was the recon for the 8pm advisory and there was an explanation of how the dropsonde did not make it to the surface to do the winds and the pressure measured was 899 so they assume it is likley to be 898 at the surface of the eye so it is 898. she is not weaking. in fact she is stil getting stronger. she has droped 3mbs each hour all day.sometimes in bigger chunks. just sit back and watch
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1058. pseabury
12:30 AM GMT on September 22, 2005
Look at the Mean Radial Velocity Profile.

Radial Velociry Radar Sig
Member Since: May 28, 2005 Posts: 0 Comments: 3
1057. Carbo04
12:29 AM GMT on September 22, 2005
has the storm stopped strengthening? the latest RECON report shows the central min. pressure is up to 899 mb. Has Rita reached her intensity peak???


read the discussion.. it says 899 but they think it's stronger since they didnt get a 100% reading. so they set it 898, and said it's probably lower.

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