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 Charmeck:

Link or info - what - where???


799. Grothar 8:42 PM EDT on August 30, 2012
Member Since: Posts: Comments:
Quoting pottery:

Post 799.


TY
Member Since: August 21, 2011 Posts: 0 Comments: 143
Your tax dollars at work.
Link Port Fourchon article about NOAA assist. Thanks CRS for calling attention to that.
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Quoting PRweathercenter:
http://www.ssd.noaa.gov/PS/TROP/floaters/12L/imag ery/swir-animated.gif


Thanks PRweathercenter.
Member Since: Posts: Comments:
Quoting Charmeck:

Link or info - what - where???

Post 799.
Member Since: October 24, 2005 Posts: 0 Comments: 24025
Quoting stormpetrol:
Leslie been on 14N line all day, simple as that! WEST!


As of 5:00 p.m....

THE INITIAL MOTION IS ABOUT 280/18. LESLIE SHOULD TURN TOWARD THE
WEST-NORTHWEST IN THE NEXT 12 HOURS OR SO AS IT MOVES AROUND THE
SOUTHWESTERN SIDE OF THE SUBTROPICAL RIDGE.

Member Since: Posts: Comments:
Quoting redwagon:

You're going to have to give points for 'colloquialism'.


Anytime someone writes a word with more than two syllables I am always impressed. I already gave them a plus for that one.
Member Since: July 17, 2009 Posts: 69 Comments: 25362
Quoting stormpetrol:
Leslie been on 14N line all day, simple as that! WEST!



and its geting closer and closer



am not really buying any of the mode runs

Member Since: May 21, 2006 Posts: 5091 Comments: 114719
Quoting stormpetrol:
Leslie been on 14N line all day, simple as that! WEST!

Looks ominising!
You think it will keep west all the way..???
Member Since: October 24, 2005 Posts: 0 Comments: 24025
What are your guys' thoughts on Leslie? It is already south of where some other great Atlantic hurricanes were when they were at the same longitude(ie: Gloria, Donna)
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Quoting indianrivguy:


42 ft wave height.. wow more than eight stories trough to crest, that's an e ticket ride der.


LOL.
Member Since: July 17, 2009 Posts: 69 Comments: 25362
827. JLPR2
Quoting stormpetrol:
Leslie been on 14N line all day, simple as that! WEST!


With what I'm starting to see in satellite images, it isn't hard to agree with that.
Member Since: September 4, 2007 Posts: 7 Comments: 8499
Quoting Grothar:



I just did "in a nutshell or "as" a nutshell :)

You're going to have to give points for 'colloquialism'.
Member Since: Posts: Comments:
Quoting HrDelta:


Very good.



The difference in that is the fact that TropicalAnalystwx13 has will have decent things to say. Bastardi is just sniveling, low-life, ignorant piece of scum.




Come on tell us what you really think! LOL

It's OK, TropicalAnalyst and I have been good friends for years. We spend most of the time insulting each other. That's what friends do!
Member Since: July 17, 2009 Posts: 69 Comments: 25362
824. JLPR2
Makes you wonder, no?

Member Since: September 4, 2007 Posts: 7 Comments: 8499
Quoting indianrivguy:


42 ft wave height.. wow more than eight stories trough to crest, that's an e ticket ride der.

Link or info - what - where???
Member Since: August 21, 2011 Posts: 0 Comments: 143
Leslie been on 14N line all day, simple as that! WEST!
Member Since: Posts: Comments:
Looks like Isaac is gonna pay me a visit. Rainfall forecast is calling from 7-8 inches of rain around the Cincinnati area.
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Quoting Grothar:
This shows a very large and strong system in the Atlantic in a few days.



42 ft wave height.. wow more than eight stories trough to crest, that's an e ticket ride der.
Member Since: Posts: Comments:
Quoting pottery:

Oh, this is getting Good !

heheheheheheh


He is someone so incompetant, he was let go. That is an achievement.

And this little Nugget from Wikipedia:

In 2012, Bastardi invoked the Madden-Julian Oscillation to predict that "drought-busting rains" would occur in the midwest/Ohio valley in June. That was the exact opposite of what actually occurred.
Member Since: Posts: Comments:
Quoting serialteg:


hey keep,

you see 'er making that WNW turn?


maybe
maybe not
we shall see soon
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting kctinney:
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?

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: 4429
Quoting opal92nwf:

Thanks for your reponses.


Wow, got an answer...not very highly regarded eh?! I've never seen him myself...have only thought about what an unfortunate name he had LOL But by their responses...is maybe fitting!?
Member Since: October 12, 2011 Posts: 0 Comments: 841
Quoting Hurricanes305:


He is like Jim Cantore but way more knowledgeable about the tropics.
How do you know that Bastardi knows more about the tropics than Cantori.? What are you basing that statement on.?
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Quoting muddertracker:


Can an ex-beefcake blowhard fit inside a nutshell?

Oh, this is getting Good !

heheheheheheh
Member Since: October 24, 2005 Posts: 0 Comments: 24025
AL, 12, 2012083100, , BEST, 0, 145N, 459W, 45, 1002, TS,
Member Since: May 21, 2006 Posts: 5091 Comments: 114719
Quoting opal92nwf:
I am not an Accuweather person. So for all you people who know about him, how would you describe Joe Bastardi in a nutshell?


Can an ex-beefcake blowhard fit inside a nutshell?
Member Since: Posts: Comments:
Quoting Grothar:


As quoted by someone with 20,939 comments LOL

Touche', my friend.
Member Since: October 24, 2005 Posts: 0 Comments: 24025
Quoting opal92nwf:

sorry for the colloquialism. I meant to say how would you briefly describe him?



I just did "in a nutshell or "as" a nutshell :)
Member Since: July 17, 2009 Posts: 69 Comments: 25362
Quoting waterskiman:

just say his last name, thats it in a nut shell.


Lol, that was funny!
Member Since: May 25, 2012 Posts: 0 Comments: 2043
Per New Orleans Channel 6: 2 bodies found in Braithwaite
Makes one wonder if others will be found in the attics of the flooded areas.
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Quoting TropicalAnalystwx13:

He talks too much.


As quoted by someone with 20,939 comments LOL
Member Since: July 17, 2009 Posts: 69 Comments: 25362
Quoting opal92nwf:

sorry for the colloquialism. I meant to say how would you briefly describe him?

Thanks for your reponses.
Member Since: May 12, 2012 Posts: 11 Comments: 2315
Quoting opal92nwf:
I am not an Accuweather person. So for all you people who know about him, how would you describe Joe Bastardi in a nutshell?

just say his last name real slow. thats it in a nut shell.

by the by he got canned from accuweather
Member Since: June 6, 2010 Posts: 0 Comments: 4429
Quoting AussieStorm:

Joe B is having a rant about the NHC. classic.


What a complete and total tool.

Hey Bastardi, how do you feel about those deaths in the aftermath of Katrina?

I hate that company so damn much.
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802. JLPR2
Quoting Charmeck:

Gust to 27.2knots


Ah yes, but that would be the gusts, I'm talking sustained winds.
Member Since: September 4, 2007 Posts: 7 Comments: 8499
801. opal92nwf
12:43 AM GMT on August 31, 2012
Quoting pottery:

Squashed up real small.

lol
Member Since: May 12, 2012 Posts: 11 Comments: 2315
800. HurrMichaelOrl
12:43 AM GMT on August 31, 2012
Quoting serialteg:


i think it's the lack of florida talk + hah...


They are beautiful storms, but considering they look to both be fish (fortunately), I don't think Kirk and Leslie will excite the blog too much.
Member Since: July 13, 2007 Posts: 0 Comments: 1073
799. Grothar
12:42 AM GMT on August 31, 2012
This shows a very large and strong system in the Atlantic in a few days.

Member Since: July 17, 2009 Posts: 69 Comments: 25362
798. avthunder
12:42 AM GMT on August 31, 2012
Quoting Hurricanes305:
Slow blog tonight considering we have 2 strengthening tropical systems right now.
I think there is a bit of exhaustion after Isaac. Will get active again over the weekend.
Member Since: August 30, 2010 Posts: 0 Comments: 326
797. Charmeck
12:41 AM GMT on August 31, 2012
Quoting JLPR2:


??
It is 23.3knots.

Gust to 27.2knots
Member Since: August 21, 2011 Posts: 0 Comments: 143
796. Hurricanes305
12:41 AM GMT on August 31, 2012
Quoting JLPR2:


Hmm... Suspicious looking arc in the deep convection, eye wall trying to form?


Could wake tomorrow to a 70 mph system or a hurricane based on how it has strengthen ever advisory! By far the most well develop storm this year. Probably more than all of 2011 as well.
Member Since: May 25, 2012 Posts: 0 Comments: 2043
795. JLPR2
12:40 AM GMT on August 31, 2012
Quoting Charmeck:

That would be KNOTS - 31 MPH


??
It is 23.3knots.

23.3knots = 27mph
Member Since: September 4, 2007 Posts: 7 Comments: 8499
794. CosmicEvents
12:40 AM GMT on August 31, 2012
Quoting opal92nwf:
I am not an Accuweather person. So for all you people who know about him, how would you describe Joe Bastardi in a nutshell?
LOL...what a question.
.
In a nutshell, think very cold waters effects on the male of the species.
.
.
Whatever met knowledge he has got thrown out long ago to sell the hype and fear of the "next" storm.
Member Since: August 3, 2005 Posts: 10 Comments: 5526
793. waterskiman
12:40 AM GMT on August 31, 2012
Quoting galvestonhurricane:
Good to see Isaac finally pulling away from Louisiana. Anyway, I need help with one of my AP Chemistry problems. Here it is: How would you synthesize chromyl chloride (CrO2Cl2)? What precautions might you take? Is it likely to be a liquid or a solid at ordinary temperatures, and what is its likely color?

Can't you just google it. I read about it interesting to say the least. My one thing learned for today, but have no idea what you would use it for. Safe breaking maybe??
Member Since: June 6, 2010 Posts: 0 Comments: 4429
792. Charmeck
12:39 AM GMT on August 31, 2012
Quoting JLPR2:


Yeah, 1005mb, though 27mph winds aren't impressive.

That would be KNOTS - 31 MPH
Member Since: August 21, 2011 Posts: 0 Comments: 143
791. CaicosRetiredSailor
12:39 AM GMT on August 31, 2012
Port Fourchon: A Critical Piece of Isaac No One Is Talking About

BY MIKE SCHULER ON AUGUST 30, 2012

Editor's Note: While Hurricane Isaac mostly spared Gulf of Mexico oil and gas production, concerns are mounting over the condition of Port Fourchon, LA where the%uFFFDmain hub of the Gulf offshore activity lies. Isaac delivered a direct hit to area, if not two, but little information has been released concerning damage to the port and main stream media outlets have all but forgotten the "Gulf's Energy Connection". So far all we know is that sections of LA 1, the only road in and out of Port Fourchon, have been washed out and it will likely be another 24 hours before we know the true extent of damage and flooding.

...

Here's a little about what NOAA is doing to assess the damage.

NOAA A rapid maritime response by NOAA's Office of Coast Survey will likely pay dividends to the U.S. economy, as a high-tech survey team today began surveying the channels of Port Fourchon, the "Gulf's Energy Connection," to search for dangers to navigation caused by Hurricane Isaac.

...

http://gcaptain.com/port-fourchon-isaac-impact/
Member Since: July 12, 2007 Posts: 0 Comments: 5996
790. beell
12:39 AM GMT on August 31, 2012
Quoting StormDrain:
Thank you, beell, for your answer and for taking time to make the graphic. Makes sense.
:)

Guess the biggest ? I been trying to understandd is whether the surge came upriver (as Plaquemines Parish President Billy Nungesser seemed to suggest in a news conference on wwltv Wednesday morning... perhaps I misheard him), over land/swamp, or both.

Best wishes to your family and to all who've been affected by Isaac.


YW, SD.

I think it came over the very much depleted marsh between the Mississippi River and the Mississippi River Gulf Outlet Canal-but not certain.
Member Since: September 11, 2007 Posts: 141 Comments: 16213
789. Hurricanes305
12:38 AM GMT on August 31, 2012
Quoting opal92nwf:
I am not an Accuweather person. So for all you people who know about him, how would you describe Joe Bastardi in a nutshell?


He is like Jim Cantore but way more knowledgeable about the tropics.
Member Since: May 25, 2012 Posts: 0 Comments: 2043
788. JLPR2
12:37 AM GMT on August 31, 2012
Quoting PRweathercenter:
Lcould you send me the link for the bouy?


Sure.

Here is the buoy.

Here is the link to the buoy page.
Member Since: September 4, 2007 Posts: 7 Comments: 8499

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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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