Isaac slamming Gulf Coast with damaging floods, tornadoes

By: Dr. Jeff Masters , 4:44 PM GMT on August 30, 2012

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Slow-moving Tropical Storm Isaac continues to hammer coastal Louisiana, Mississippi, Alabama, and Florida's Panhandle with tornadoes, torrential rains, high winds, and a damaging storm surge. Over the past 24 hours, destructive tornadoes have touched down in Biloxi and Pascagoula, Mississippi, and one person was killed by a tree falling on a car in Pearl River County, Mississippi. A major flood event is occurring in Slidell, Louisiana, where Isaac's storm surge filled Bayou Bonfouca and the W-14 Canal, inundating portions of the city with 1 - 5 feet of water. While Isaac is now a weakening minimal-strength tropical storm, it is still a potent rainmaker, and will cause damaging floods all along its path for the next three days. Major river flooding is occurring or is about to occur on a number of rivers in the landfall area. In north central Tangipahoa Parish in southeast Louisiana and southwestern Pike County in southern Mississippi, a mandatory evacuation has been ordered for all low-lying areas and along the Tangipahoa River, due to the potential failure of the Lake Tangipahoa dam. Audubon Park in New Orleans, recorded 11.19" of rain as of 7 pm Wednesday night. An earlier amount of 19" was found to be erroneous, and this is not a 24-hour precipitation record for the city. According to wunderground's weather historian, Christopher C. Burt, New Orleans' greatest 24-hour rainfall on record is 14.01" on July 24 - 25, 1933. The Louisiana official state 24-hour record is 22.00" on Aug. 29, 1962 at Hakberry, although U.S. Army Corps of Engineers `Storm Studies' mentions a 23.80" falling in a 24-hour period at Millers Island during a TS on Aug 7-8, 1940. Storm total was 37.50" over a 60-hour period there during that event.

A few other rainfall totals from Isaac, through 11 am EDT on Thursday:

15.02" Marion, MS
10.09" Hattiesburg, MS
10.15" Gulfport, MS
9.80" Slidell, LA
9.74" Biloxi, MS
8.52" Mobile, AL
5.57" Baton Rouge, LA


Figure 1. Isaac's winds and storm surge overcomes the seawall and floods South Beach Boulevard in Waveland, Miss., Wednesday, Aug. 29, 2012, the seventh anniversary of Hurricane Katrina hitting the Gulf Coast. (AP Photo/Rogelio V. Solis). Waveland experienced a storm surge in excess of 5' for 36 hours.

Isaac's storm surge winds down
Storm surge levels along the coast of Mississippi and surrounding areas are gradually receding, and the surge has finally fallen below 5' at Waveland, which experienced a storm surge in excess of 5' for 36 hours. Isaac's storm surge levels were characteristic of a Category 2 hurricane, and lasted for an exceptionally long period of time. Waveland, Mississippi experienced a peak surge of 8' and peak storm tide of 9' (surge plus the natural high tide), which beat the levels that occurred during Category 2 Hurricane Gustav of 2008 (7' of storm tide.) The peak 11.06' storm surge at Shell Beach, which is in Lake Borgne, 30 miles southeast of New Orleans, exceeded the 9.5' surge recorded there during Gustav. According to an article in nola.com, Isaac pushed a storm surge of 13.6' into Lake Borgne, on the east side of New Orleans. This is not far from the 15.5' storm surge Hurricane Katrina brought to the location. It is quite possible that Isaac's storm surge might have breached levees of the east side of New Orleans, flooding areas inhabited by tens of thousands of people, had the Army Corps of Engineers not completed their $14.5 billion upgrade to the New Orleans flood defenses this year. I estimate that storm surge damage from Isaac will exceed $2 billion. Isaac has likely caused $2.5 billion in insured damage not related to flooding, insurance firm Eqecat estimated yesterday. Here were some of the peak storm surge values that were recorded at NOAA tide gauges during Isaac:

11.1' Shell Beach, LA
8.0' Waveland, MS
3.5' Pensacola, FL
4.6' Pascagoula, MS
3.8' Mobile, AL


Figure 2. A TRMM satellite 3-D view of rainfall on Aug. 28 showed a few very powerful thunderstorms near Isaac's eye were reaching heights of almost 17 km (10.6 miles.) Intense bands of rain around Isaac were occasionally dropping rain at a rate of over 2.75 inches per hour. Image credit: SSAI/NASA, Hal Pierce.

Isaac's storm surge on the Mississippi River
A storm surge estimated at 12' moved up the Mississippi in Plaquemines Parish near Port Sulphur, LA, near 8:30 pm EDT Tuesday, causing overtopping of the levees and flooding of homes in the mandatory evacuation areas behind the levees. These levees were not part of the $14.5 billion levee upgrade New Orleans got after Hurricane Katrina, and were not rated to Category 3 hurricane strength, like the levees protecting New Orleans are. Since salt water is more dense than fresh water, the surge travelled along the bottom of the river, with the fresh water flow of the river lying on top. The surge continued upriver, and before reaching New Orleans, encountered an underwater barrier in Plaquemines Parish. This barrier was constructed by the Army Corps of Engineers beginning on August 15, in order to keep salt water from moving upstream and contaminating drinking water for Plaquemines Parish and New Orleans. Salt water had made it 90 miles upriver to the outskirts of New Orleans, due to the low flow rate of the river (which had dropped 7' below average in height due to the drought of 2012.) According to a spokesperson for the National Weather Service River Forecast Office, this barrier was probably able to completely block the flow of salt water upriver due to Isaac's storm surge, and no salt water made it as far as New Orleans. However, the massive intrusion of ocean water into the river channel caused the mighty Mississippi's fresh water flow to back up for hundreds of miles. Water levels were elevated by 10' in New Orleans (103 miles upstream from the mouth of the Mississippi), 8' in Baton Rouge (228 miles upstream), and 1.4' at Knox Landing, an amazing 314 miles upstream.

Hurricane Kirk in the Central Atlantic
Hurricane Kirk intensified into a 75 mph Category 1 hurricane this morning, becoming the busy 2012 Atlantic hurricane season's fifth hurricane. With the season's mid-point of September 10 still almost 2 weeks away, we've already had 12 named storms and 5 hurricanes, which is close to what an entire season experiences in an average year (11 named storms and 6 hurricanes.) Kirk should stay well out to sea and not trouble any land areas.


Figure 3. Morning satellite image of Hurricane Kirk.

Tropical Storm Leslie forms in the Central Atlantic
Tropical Storm Leslie has formed in the Central Atlantic. Leslie's formation on August 30 puts 2012 in 2nd place for earliest formation date of the season's 12th storm. Only 1995 had an earlier formation date of the season's 12th storm. With records dating back to 1851, this year is only the second time 8 total storms have formed in August. The other year was 2004, when the first storm of the season formed on August 1 (Alex), and the 8th storm (Hermine)
formed on August 29th. Leslie is organizing quickly, and appears destined to become a hurricane before the week is out. Fortunately, Hurricane Kirk is weakening the ridge of high pressure to the north of Leslie, and Leslie is expected to turn to the northwest and miss the Lesser Antilles Islands. In the long term, it remains unclear if Leslie will follow Kirk and fully recurve out to sea. The latest 2 runs of the GFS model have predicted that Leslie will recurve out to sea and not threaten any land areas, but the latest 2 runs of the ECMWF model have predicted that the trough of low pressure pulling Kirk to the northeast will not be strong enough to recurve Leslie out to sea. Instead, the ECMWF predicts that a ridge of high pressure will build in early next week, forcing Leslie more to the northwest, making the storm a potential threat to Bermuda, then to the Northeast U.S. and Canada in 8 - 11 days.

Jeff Masters

Hurricane Isaac Louisiana (apphotos)
Two men walk in the storm surge from Isaac, on Lakeshore Drive along Lake Pontchartrain, as the storm approaches landfall, in New Orleans, Tuesday, Aug. 28, 2012. (AP Photo/Gerald Herbert)
Hurricane Isaac Louisiana
west palm beach flood isaac (alishu)
West Palm Beach flood from Isaac
west palm beach flood isaac
Hurricane Isaac Impacts Navarre Beach & Pier10 (jennjeff1)
Hurricane Isaac versus Navarre Beach Pier, the longest concrete pier on the Gulf of Mexico
Hurricane Isaac Impacts Navarre Beach & Pier10

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Quoting muddertracker:


Kirk is a beautiful little 'cane.

I liked Gordon Better ;)

It's eye made up half of the storm by itself. xD
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The proof, as they say, is in the pudding:

JB's 2012 hurricane season forecast: 9-12/4-6/2-3. (The seasons's still two weeks from the peak.)

JB's spring and summer 2012 forecast: "The summer will not be as hot (more like 2009) and winter could last into April this year, centered on the [Great] Lakes."

JB's winter, 2012 forecast: "...next winter [2012], for example, will be colder than this one [2011]."

I could go on and on, but this is way too easy. Just Google any of JB's old forecasts--the ones that haven't been removed, that is--and you'll see much of the same: huge, grandstanding forecasts that go against both common sense and climatology, followed by a deafening silence when those forecasts inevitably turn out to be wrong. The bottom line is, his spoken ideology makes him desperately want the globe to cool, and that's not happening. He just hasn't realized or admitted to that yet.
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Quoting Grothar:
The two blobs are joining and making one big blob. It looks like Leslie is still a little elongated from North to South.



Not really elongated where it affects development at all its well stacked up which is more important it due for some chunks of intensification. Until some dry air keeps it in check from become greater than a Cat. 3 we shall see!
Member Since: May 25, 2012 Posts: 0 Comments: 2043
So, the forecast calls for Leslie to be a Hurricane, late on Friday.
The wave forecast is for 40' storm waves, north of Puerto Rico.

The surfers must be salivating all over....
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932. JLPR2
Quoting serialteg:


talking about stack... lets make the latest cmiss rounds

first the buoy (JLPR)













aha! south reloc? lol





now lookit this anticyclone! nice



Either that is the center of Leslie or the storm is weaker than we think. 14mph this close to it? O.o
Member Since: September 4, 2007 Posts: 7 Comments: 8747
Quoting Relix:
I'll worry about Leslie tomorrow. NHC, models and meteorologists are pretty much in the same line about it missing the islands.


11 Pm advisory forecast:
Tropical Depression Isaac
Final Advisory.
Hurricane Kirk
105 Mph
976 MB
Moving Northward out to sea.

INIT: 105 Mph
12 HRS: 115 Mph
24 HRS: 125 Mph
36 HRS: 125 Mph
48 HRS: 110 Mph
72 HRS: 90 Mph
94 HRS: 75 Mph
120 HRS: ABSORBED

Tropical storm Leslie
45 Mph
1004 MB
Moving Westward, expected to lift north of the islands and out to sea, East of Bermuda.

INIT: 45 Mph
12 HRS: 60 Mph
24 HRS: 70 Mph
36 HRS: 75 Mph
48 HRS: 85 Mph
72 HRS: 100 Mph
84 HRS: 110 Mph
96 HRS: 110 Mph--- less favorable enviroment interaction.
120 HRS: 115 Mph
144 HRS: 125 Mph
168 HRS: 135 Mph E-ESE of Bermuda.


I will post a tracking map LATE Friday night, or Saturday morning.
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Quoting FLPandhandleJG:


Hurricane Kirk


Kirk is a beautiful little 'cane.
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Quoting waterskiman:

If your from the caymans why do you give a crap about US politics stirring the pot maybe
hey, hey....US politics/actions effect the whole world. Stormpetrol has a right to an opinion. SP...I assume you're leaning west?
Member Since: August 3, 2005 Posts: 10 Comments: 5684
Weakening Isaac still threatens Louisiana, Mississippi

...In LaPlace, La., about 28 miles north and west of New Orleans, the National Guard was evacuating 3,000 people trapped by flooding, the governor's office said. Jindal said they were rescuing about 30 people an hour...
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Hurricane Kirk
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Quoting muddertracker:


Dolly she ain't.

Getting there quick, though.
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Quoting waterskiman:

If your from the caymans why do you give a crap about US politics stirring the pot maybe
Actually US politics affect us in the Cayman Islands more than you may know.
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Quoting pottery:

Very nice , thanks.

Well-stacked, indeed.
But then I would expect that, with a name like Leslie.


Dolly she ain't.

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Quoting HurricaneDean07:

Michael is emerging off the coast. and Nadine is located in central Africa ;)


Sounds like a scene from one of the daytime soap operas.

(Meanwhile Kirk and Leslie are still stuck in the Atlantic)
Member Since: July 17, 2009 Posts: 71 Comments: 27208
Quoting Grothar:
The two blobs are joining and making one big blob. It looks like Leslie is still a little elongated from North to South.



kinda isaac wise, i believe thats the pattern as well as better conditions for HURRicanes in more N lats
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Quoting CosmicEvents:
But he's right as often as a monkey throwing darts. Still, if you want to follow and pay for his long-range forecasts go right ahead. I understand that you can pay extra to get the "real secret forecast" if you want.




Horsefeathers.
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Quoting serialteg:


talking about stack... lets make the latest cmiss rounds

first the buoy (JLPR)













aha! south reloc? lol





now lookit this anticyclone! nice


Very nice , thanks.

Well-stacked, indeed.
But then I would expect that, with a name like Leslie.
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Signing off. A blessed night to all..:)
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Quoting stormpetrol:
Bastardi , aw well one thing he is an Obama basher, that doesn't disqualify him as a meteorologist, but he appears to go against science, mind you I'm a believer in Intelligent Design , along with Evolution factoring in. But Bastardi IMO is much like GOP he represents, he just doesn't realize reality, nuff said! Now let's see where the punches come from!


As a person who believes in Theistic Evolution, I have to disagree with middle of yours.

Now, off of this Bastardi Clown. Has there been any updates on the T numbers for Kirk and Leslie?
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The two blobs are joining and making one big blob. It looks like Leslie is still a little elongated from North to South.

Member Since: July 17, 2009 Posts: 71 Comments: 27208
Quoting stormpetrol:
Bastardi , aw well one thing he is an Obama basher, that doesn't disqualify him as a meteorologist, but he appears to go against science, mind you I'm a believer in Intelligent Design , along with Evolution factoring in. But Bastardi IMO is much like GOP he represents, he just doesn't realize reality, nuff said! Now let's see where the punches come from!

If your from the caymans why do you give a crap about US politics stirring the pot maybe
Member Since: June 6, 2010 Posts: 0 Comments: 4458
Quoting Grothar:

Michael is emerging off the coast. and Nadine is located in central Africa ;)
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912. Relix
I'll worry about Leslie tomorrow. NHC, models and meteorologists are pretty much in the same line about it missing the islands.
Member Since: August 3, 2006 Posts: 0 Comments: 2741
Quoting PensacolaDoug:
I'd like to see you bashers try to make a living at ultra-long range forecasting. No-one else really goes out on a limb like he does. It's a very daunting job.
But he's right as often as a monkey throwing darts. He's selling the idea that he can forecast the unforecastable. Still, if you want to follow and pay for his long-range forecasts go right ahead. I understand that you can pay extra to get the "real secret forecast" if you want.
Member Since: August 3, 2005 Posts: 10 Comments: 5684
Quoting stormpetrol:
Bastardi , aw well one thing he is an Obama basher, that doesn't disqualify him as a meteorologist, but he appears to go against science, mind you I'm a believer in Intelligent Design , along with Evolution factoring in. But Bastardi IMO is much like GOP he represents, he just doesn't realize reality, nuff said! Now let's see where the punches come from!


thank goodness you didn't mention global warming in your post...could you work that in? j/k lol..*gloves up* dude.
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Quoting kctinney:


Thank you for responding, at least ONE person responds to a legit question vs bashing others. :)

Well 2 I answered you last page posted it again though
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Quoting kctinney:
Ok, will try again,

What is everyone's feelings on the dam breaking and the manual breaching of it...........I'm afraid they will end up making it break and flood d/t pressure from water built up against it............plus aren't they still getting rain?


Its only 700 acres, that's not a lot of volume and the river valley is pretty broad, so even if it lets go I don't think it will be so bad. They have had ample time to move those in danger. Every lil' bit they dump lessens the danger too, so I think continued dumping is prolly a good course of action/relief. If memory serves, right now, the wind fetch should be away from the struggling damn toward the northern end.
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907. JLPR2
I miss Quickscat so bad...

Member Since: September 4, 2007 Posts: 7 Comments: 8747
Quoting TropicalAnalystwx13:

*passes insult to Joe Bastardi*

At least the information I put out is useful and makes sense.
Like I said, Joe is actually very smart. I've learned a lot from Bastardi as far as looking at patterns and the pattern evolution. I know Levi has also mentioned many times that he learned a lot from him as well. So the basis of his forecasts are very intelligent. The problem lies in his forecasts themselves. That is where his personality gets the best of him.
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If he was fired, they sure kept him around for a long time.,................WIKI....Born July 18, 1955
Providence, Rhode Island
Residence Boalsburg, PA
Citizenship United States
Fields Meteorology
Institutions Accuweather, WeatherBELL
Alma mater Penn State UniversityBastardi was born in Providence, Rhode Island. He spent his childhood moving frequently, first to Texas in 1960, then to Somers Point, New Jersey in 1965. His fascination with weather dates to his childhood; he reportedly carried an anemometer around with him as a teenager to measure wind speed. He enrolled at Penn State University, where he was a member of the varsity wrestling team. He graduated with a degree in meteorology on March 4, 1978. In 1992 at age 37, Bastardi married Jessica Jane Strunck, age 26, also a Penn State graduate. They have a son Garrett (born 1996) and a daughter Jessica (born 1998). In his free time, Bastardi enjoys bodybuilding, and has won the NABBA American Bodybuilding Championships.

Bastardi worked for AccuWeather from 1978 until February, 2011. He joined WeatherBell Analytics LLC in March, 2011
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Quoting WXGulfBreeze:


In any battle of wits, some come to the fight unarmed.

Nice.
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Member Since: July 17, 2009 Posts: 71 Comments: 27208
Quoting redwagon:

Stay on the microwave, I think the MW is the best portent, first to depict stack and direction. Vital signs, so to speak.


talking about stack... lets make the latest cmiss rounds

first the buoy (JLPR)













aha! south reloc? lol





now lookit this anticyclone! nice

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901. JeffM
Quoting PensacolaDoug:
All of you Bastardi Bashers? He's respected among meteorologists. You guys couldn't carry his briefcase.


Completely agree. He likes to overhype stuff but I think he is just a high-energy guy.

Make no mistake, the dude knows the weather.
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lol
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Bastardi , aw well one thing he is an Obama basher, that doesn't disqualify him as a meteorologist, but he appears to go against science, mind you I'm a believer in Intelligent Design , along with Evolution factoring in. But Bastardi IMO is much like GOP he represents, he just doesn't realize reality, nuff said! Now let's see where the punches come from!
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Quoting Grothar:


Yes, they are still getting rain and the Army Corps of Engineers and other specialists are making very sure they try and make the correct decision as to when and where they make the breach. It is still a developing story and when they have reached their decision, we should know. Nothing really new has come out recently. We are all waiting.


Thx Grothar!
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Quoting AstroHurricane001:
Interesting.



More ridging?
Member Since: May 25, 2012 Posts: 0 Comments: 2043
Quoting TropicalAnalystwx13:

*passes insult to Joe Bastardi*

At least the information I put out is useful and makes sense.

Sure... lol. Its good information and helps people, most here do that.
Member Since: March 16, 2012 Posts: 127 Comments: 7972
Quoting Cat5hit:
I see I stepped into a 5hit 5torm of folks having a battle of whits.


In any battle of wits, some come to the fight unarmed.
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Quoting pottery:

Well, I have read what the news is saying, but it makes not much sense to me.
I don't know the area....

Sounds like they are trying to save a bad situation.
If the dam goes, there will be flash flooding.
If they let the water out slowly, there will be flooding but it will be less severe.

That's my take...


Thank you for responding, at least ONE person responds to a legit question vs bashing others. :)
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Quoting waterskiman:

Last word was they are fortifying the bank that has sloffed off. I saw the aireal on it and it was a big hole as big as the spill way the cement top on it was ready to go at any second. Once they do that then it's up to the engineers to do their thing.
Member Since: June 6, 2010 Posts: 0 Comments: 4458
Quoting kctinney:


Could you please answer my question then that I have posed (now) 3 times? TIA

What is everyone's feelings on the dam breaking and the manual breaching of it...........I'm afraid they will end up making it break and flood d/t pressure from water built up against it............plus aren't they still getting rain?



Yes, they are still getting rain and the Army Corps of Engineers and other specialists are making very sure they try and make the correct decision as to when and where they make the breach. It is still a developing story and when they have reached their decision, we should know. Nothing really new has come out recently. We are all waiting.
Member Since: July 17, 2009 Posts: 71 Comments: 27208
Quoting TomTaylor:
He also insisted many times that the east US would see a flip to a big winter last year. Never really happened. He also anticipated a cool summer over the midwest in late spring and summer. Ended up horribly wrong there.

The point is Joe is too aggressive and tries too hard to make the big forecast.


Sounds like a lot of folks on this blog.
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Quoting Hurricanes305:


Cantore is more of a Weather enthusiast than met and have a wide range of knowledge of tornadoes and severe weather where a majority of his respect is earn as well as being the first to volunteer to be in the middle of the storm I have tremendous respect for him in that regard. However I seen Bastardi nail tropical system from a far. His rants and extreme wishcasting has derail his significance in tropical forecasting. Over the years he has made emotions cloud his judgement which many people have done. While I see some maturation in Jim Cantore's meteorological process.
I really couldnt say who is more knowledgeable on the subject. I do not even know there educational background. They both seem to know what there talking about where the tropics are concerned. I do know the Bastardi is almost ten years older than Cantori, so he may have more experience.
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Quoting kctinney:


Could you please answer my question then that I have posed (now) 3 times? TIA

What is everyone's feelings on the dam breaking and the manual breaching of it...........I'm afraid they will end up making it break and flood d/t pressure from water built up against it............plus aren't they still getting rain?



Well, I have read what the news is saying, but it makes not much sense to me.
I don't know the area....

Sounds like they are trying to save a bad situation.
If the dam goes, there will be flash flooding.
If they let the water out slowly, there will be flooding but it will be less severe.

That's my take...
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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.

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