Massive tornado outbreak kills 202; 100-year flood coming on Mississippi River

By: Dr. Jeff Masters , 1:49 PM GMT on April 28, 2011

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A stunning tornado outbreak of incredible violence has left at least 202 dead across the Eastern U.S.; injuries probably number over a thousand, with 600 injured in the town of Tuscaloosa alone. The tornadoes carved huge swaths of damage, completely flattening large sections of many towns, and damage from the storms is likely to be the greatest in history for any tornado outbreak. Hardest hit was Alabama, with at least 149 dead; at least 36 were killed in neighboring Mississippi. NOAA's Storm Prediction Center logged 160 preliminary reports of tornadoes between 8am EDT yesterday and 8am EDT today. At least 11 of these tornadoes were killer tornadoes; deaths occurred in six states. Damage from some of these storms appeared to be at least EF-4, and it is likely that there were multiple violent EF-4 or EF-5 tornadoes. The death toll makes the April 27 - 28 outbreak the third deadliest tornado outbreak of the past 50 years, behind the April 3 - 4, 1974 Super Outbreak (315 killed) and the 1965 Palm Sunday tornado outbreak (256 killed.)


Figure 1. Damage in Birmingham, Alabama from last night's tornado. Image posted to twitter.


Figure 2. Damage in Tuscaloosa, Alabama from last night's tornado. Image posted to twitter, photographer unknown.


Figure 3. Radar reflectivity image of the Tuscaloosa, Alabama tornado.

The 3-day total of preliminary tornado reports from this outbreak is 278, close to the 323 preliminary tornado reports logged during the massive April 14 - 16 tornado outbreak. That outbreak has 155 confirmed tornadoes so far, making it the largest April tornado outbreak on record. It is unprecedented to have two such massive tornado outbreaks occur so close together. According to a list of tornado outbreaks maintained by Wikipedia, only two other tornado outbreaks have had as many as 150 twisters--the May 2004 outbreak (385), and the May 2003 outbreak (401).


Figure 4. Satellite image of last night's storm at 8:15pm EDT April 27, 2011. Image credit: NASA/GSFC.

Tornado outbreak winding down today
Tornado warnings continue to be issued this morning along the cold front now pushing towards the Atlantic coast, and a tornado was reported at 7:35am EDT in McBee, South Carolina. NOAA's Storm Prediction Center has placed a large swath of the coast, from Florida to Vermont, in their "Slight Risk" region for severe weather. The high instability and high wind shear that triggered so many killer tornadoes yesterday is gone, and we should see only a few weak tornadoes today. No severe storms are predicted for Friday. Saturday has a slight risk of severe weather over Oklahoma and Texas.


Figure 5. Severe weather threat for Thursday, April 28, 2011.


Figure 6. Remarkable video of the tornado that hit Tuscaloosa, Alabama yesterday. Fast forward to minute four to see the worst of the storm.


Figure 8. Tornado near Empire, Alabama, moving rapidly down a hill.

Unprecedented flooding predicted on Ohio and Mississippi Rivers
This week's storm system, in combination with heavy rains earlier this month, have pushed the Ohio River and Mississippi River to near-record levels near their confluence. The Ohio River at Cairo, Illinois is expected to crest at 60.5 feet on May 1. This would exceed 100-year flood stage, and be the highest flood in history, besting the 59.5' mark of 1937. Heavy rains of 10 - 15 inches have inundated the region over the past few days, and one levee breach at Black River levee near Poplar Bluff, Missouri, has resulted in the evacuation of over 500 homes. Poplar Bluff has received 15.45" of rain since Friday morning. The greatest rain gauge-measured precipitation from the storm occurred in Springdale, Arkansas, where 19.70" inches has fallen since Friday morning.


Figure 9. The latest River Flood Outlook from NOAA shows major flooding is occurring over many of the nation's major rivers.

Record 100+ year flood expected on Mississippi River
Snow melt from this winter's record snow pack across the Upper Mississippi River has formed a pulse of flood waters that is moving downstream on the Mississippi, and is currently located in Iowa. When this floodwater pulse moves south of Cairo, Illinois over the next two weeks, it will join with the record water flow coming out of the Ohio River, and create the highest flood heights ever recorded on the Mississippi, according to the latest forecasts from the National Weather Service. Along a 400-mile stretch of the Mississippi, from Cairo to Natchez, Mississippi the Mississippi is expected to experience the highest flood heights since records began 100 or more years ago, at 5 of the 10 gauges on the river along this stretch. The records are predicted to begin to fall on May 3 at New Madrid, and progress downstream to Natchez by May 20. Areas that are not protected by levees can expect extensive damage from the flooding, and it is possible that the Army Corps of Engineers will have to intentionally dynamite a levee at Birds Point and New Madrid, Missouri to protect the town of Cairo from flooding.

The Mississippi River at New Madrid, MO, about 40 miles downstream of the confluence of the Mississippi and Ohio Rivers, is currently at 44', the 3rd highest flood in history. The river is predicted to crest on Tuesday very near the all-time record height of 48 feet. The NWS warns that at this height, "Large amounts of property damage can be expected. Evacuation of many homes and businesses becomes necessary." Previous record heights at this location:

(1) 48.00 ft on 02/03/1937
(2) 44.60 ft on 04/09/1913
(3) 43.60 ft on 04/04/1975
(4) 43.50 ft on 02/16/1950
(5) 42.94 ft on 03/17/1997

The timing of the floods crests will depend upon a complex mix a factors, including how much rain falls over the next month, the possible influence of southerly winds holding up the floodwater pulses, the potential opening of flood control structures and reduction of flows from flood control reservoirs, and potential levee failures (no levee has failed on the Lower Mississippi south of the Ohio River junction since 1950, however.) The Mississippi River is expected to crest at 17 feet at New Orleans on May 22, three feet below the top of the levees. This would likely require opening of the Bonnet Carre Spillway 28 miles upstream from New Orleans, to relieve pressure on the city's levees. Opening the spillway drains 250,000 cubic feet per second of flow into Lake Pontchartrain.

Helping out tornado victims
For those who want to lend a helping hand to those impacted by the widespread destruction this month's severe weather has brought, stop by the portlight.org blog.

Related post: Are tornadoes getting stronger and more frequent? The answer is--we don't know.

Jeff Masters

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102. 7544
sorry to read about all this but send some rain to so the so fla folks its been dry as a bone any relief in sight ?
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Jarrell, TX F5 damage:



Nothing left...no tubs, no foundation...NOTHING.

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Quoting cat5hurricane:

This is true. It does help mightily, yes. I would prefer that construction.
Same here. In TX, one of the first questions an insurance agent will ask you when you are looking for homeowners' insurance is the *exterior* construction of your house. Brick veneer is stronger (and cheaper in terms of rates) than hardiplank (fiber cement), which is stronger (and cheaper in rates) than wood. The brick will *still* handle some of the external load, and it will also not fracture as easily. When it fails, it will fail catastrophically, but its failure point is much higher than that of many other building materials.

I also understand that steel-reinforced poured concrete is much stronger than brick... but its also much, much less realistic to build a house out of steel-reinforced poured concrete.

Homeowner: "Welcome to by bunke... I mean house! Yes, its steel reinforced poured concrete, it cost me a mint to build, and its a nightmare hanging up ANYTHING inside, or putting in wires."
Member Since: August 3, 2008 Posts: 16 Comments: 5871
The NWS says the Tuscaloosa twister was an EF4; I wonder how many others there were at that strength or higher.

Incredible...
Member Since: November 8, 2009 Posts: 4 Comments: 13455
LMAO -- love it, even in the midst of tragedy... I'm getting lessons in physics, construction, and physiology, i.e., what colors bricks will produce when coming in contact with human beings...

The old addiction to "The" Blog kicked in quickly. Gotta' run gonna' be late to work. Good to "see" some old friends; take care and stay safe out there.
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Quoting aquak9:
sorry for the stress, glad I could bring a smile or two...and I'd NEVER throw a brick at anyone.

thanks
Member Since: August 7, 2010 Posts: 0 Comments: 1933
Quoting RitaEvac:
Storm death toll soars to 231


Everytime i refresh CNN the number goes higher :-\
Member Since: September 2, 2008 Posts: 1 Comments: 1261
sorry for the stress, glad I could bring a smile or two...and I'd NEVER throw a brick at anyone.
Member Since: August 13, 2005 Posts: 163 Comments: 25725
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Quoting pipelines:
Parkersburg EF5 Tornado
Link
Damage in Tuscaloosa

Damage in Birmingham


If this wasn't EF5 damage, it was pretty dang close.
Exactly. The line between EF4 and EF5 is terribly blurry, and highly dependent upon structural differences that are not readily apparent.

I'm aware that in the south, brick facades are not structural, but even if they aren't structural, they are highly resistant to flying object damage, and have a high resilience to strong winds in their own right. What I see in Tuscaloosa is most akin to a Cat 5 hurricane damage, which would roughly equal an EF4. There are some things I see that could be EF5, but also some things that are EF3. When assessing tornado damage, its critical to bear in mind that the environment can enhance or reduce winds in a microscale environment (a pair of two story buildings can drastically enhance wind speed between them, for example).

The professionals need to do their job with the damage assessment - our role is to do what we can to help the people impacted (www.portlight.org is a good start), and to learn what we can from this horrific event.
Member Since: August 3, 2008 Posts: 16 Comments: 5871
Storm death toll soars to 231
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53 aquak9 "If brick buildings leveled is EF4 damage, then what is EF5 damage? Powdered bricks? No bricks at all?"

Steel-framed (column&beam ala skyscrapers) buildings twisted, structurally damaged beyond repair.
Cars and trucks tossed around like matchsticks. Locomotives and heavy earthmoving equipment rolled.
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"A little info for you guys just because a building is made of brick does not make it strong, bricks are decorative not structural"

The are part of the structure when "tied" to the structure, which "should" be the case in all construction
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Quoting TampaTom:
I heard the reports of more than 150 possible tornadoes yesterday...

Man, I never thought the Super Outbreak would be surpassed....


It probably wasn't, confirmations are usually much less than reports. I'd say this outbreak probably produced around 80-100 tornadoes in a 24 hour span.
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Quoting cat5hurricane:

Debris projectiles bombarding a structure likely will heavily damage it, but not completely obliterate it off it's foundation as winds from an EF5 tornado. Unless of course, the debris is a semi-tractor trailor or something or enormous size and weight being picked up and thrown.
Yes. But, once a structure is breached, it's stability is compromised in a nado. My point is that a brick veneer helps in this regard.
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Another levee failure along the black river...this time further south into Arkansas

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MEMPHIS TN
714 AM CDT THU APR 28 2011

THE NATIONAL WEATHER SERVICE IN MEMPHIS HAS ISSUED A

* FLASH FLOOD WARNING FOR A LEVEE FAILURE IN...
LAWRENCE COUNTY IN EASTERN ARKANSAS...
RANDOLPH COUNTY IN EASTERN ARKANSAS...
THIS INCLUDES THE CITY OF POCAHONTAS...

* UNTIL 115 PM CDT THURSDAY

* AT 714 AM CDT...A LEVEE ON THE BLACK RIVER AT POCAHONTAS FAILED
CAUSING FLASH FLOODING OF IMMEDIATELY SURROUNDING AREAS...MAINLY
ON THE EAST BANK OF THE RIVER.

* LOCATIONS IMPACTED INCLUDE COLLEGE CITY...O`KEAN...POCAHONTAS AND
PORTIA

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The next system could be a rain event with a little severe weather...
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Quoting aquak9:


so if I throw a brick at you, it's only gonna decorate you?

LOL, first time I smiled since watching TWC last night
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Member Since: September 2, 2008 Posts: 1 Comments: 1261


EF5 Damage- Greensburg Kanas

Member Since: August 7, 2010 Posts: 0 Comments: 1933
Quoting cat5hurricane:

Precisely. Particularly down south, in a warmer climate.

A Brick structure could be either a brick veneer style, which is essentially a wood frame structure. More likely than not, most residential homes are built under this construction, particularly down south where it gets very hot in the summer. Solid brick structures such as what you would frequently see in Chicago in a cold climate are three or four layers thick, and thus provide the structure.

However, if many of these brick building were commercial structures, then the construction would be to a higher code, and thus likely solid masonry. Either way, a tornado doing EF5 damage would completely destroy anything short of Nuclear Containment Buildings or certain government buildings. In other words, gone.

I guess I haven't moved to the point of wanting to debate EF4, EF5, whatever. The will be decided. People are the important aspect right now.
Member Since: October 24, 2006 Posts: 0 Comments: 1910
Quoting aquak9:


so if I throw a brick at you, it's only gonna decorate you?
LOL His colors will be black and blue.
Member Since: March 28, 2008 Posts: 0 Comments: 1532
Member Since: September 2, 2008 Posts: 1 Comments: 1261
ok, ok...I understand the EF5 damage.

Thank goodness I didn't ask about necrotizing spider bites.
Member Since: August 13, 2005 Posts: 163 Comments: 25725
Quoting aquak9:


so if I throw a brick at you, it's only gonna decorate you?
That was funny even during a not funny situation. I was thinking re-enforced concrete block could have a chance against a mighty EF-5 . (if done properly).
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Quoting eddy12:
A little info for you guys just because a building is made of brick does not make it strong, bricks are decorative not structural
...for holding up the roof, etc. But they are far, far better to be behind than vinyl siding when 2x4s are being tossed around like missiles.

How much of a home's destruction comes from wind, alone, and how much comes from wind laden with penetrating debris? The ultimate ability to withstand a nado does have something to do with the facade's ability to withstand the bombardment of debris.
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Totally crazy graphic of the 2011 tornadoes and other severe weather reports listed so far...

http://www.spc.noaa.gov/climo/online/monthly/2011 _annual_summary.html
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Parkersburg EF5 Tornado
Link
Damage in Tuscaloosa

Damage in Birmingham


If this wasn't EF5 damage, it was pretty dang close.
Member Since: July 10, 2008 Posts: 0 Comments: 225
EF5 damage... eye opening

Total destruction of buildings.

Strong framed, well built houses leveled off foundations and swept away; steel-reinforced concrete structures are critically damaged; tall buildings collapse or have severe structural deformations.
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F5 style damage..
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Quoting eddy12:
A little info for you guys just because a building is made of brick does not make it strong, bricks are decorative not structural


so if I throw a brick at you, it's only gonna decorate you?
Member Since: August 13, 2005 Posts: 163 Comments: 25725
well I can't see videos right now...but ok, EF5 is no bricks at all, I understand.
Member Since: August 13, 2005 Posts: 163 Comments: 25725
Quoting aquak9:
If brick buildings leveled is EF4 damage, then what is EF5 damage?

Powdered bricks?
No bricks at all?

The brick buildings I saw had missing roofs, doors and windows. Their brick facade was mostly intact, which shows "severe" damage, but not being leveled. If its leveled (usually considered as more than 50% of that part of the structure missing), thats a hallmark of an EF5. Trees being stripped and broken in half is a sign of EF3+. Strong wood frame buildings being leveled is also EF3+. Asphalt removed or peeled from the roadway is probably one of the easier signs of an EF5.
Member Since: August 3, 2008 Posts: 16 Comments: 5871
Quoting aquak9:
If brick buildings leveled is EF4 damage, then what is EF5 damage?

Powdered bricks?
No bricks at all?


Yeah, not only knocked down, but the slab swept clean... the difference between an EF4 and EF5 is pretty small... the damage is pretty well complete and total...
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Quoting aquak9:
If brick buildings leveled is EF4 damage, then what is EF5 damage?

Powdered bricks?
No bricks at all?

Yes. no bricks at all; foundations scoured clean.

I just wanted to post this newly-released video to remind weather-lovers that not all columnar vortices are black and ugly bringers of death and destruction (00:14 through 00:24 is the best):

Member Since: November 8, 2009 Posts: 4 Comments: 13455
I heard the reports of more than 150 possible tornadoes yesterday...

Man, I never thought the Super Outbreak would be surpassed....
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Quoting aquak9:
If brick buildings leveled is EF4 damage, then what is EF5 damage?

Powdered bricks?
No bricks at all?


according to TWC, EF5 would be nothing there..obliterated..
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Quoting jeffs713:
If we start seeing asphalt torn up, or brick buildings leveled to waist or knee high, we're talking EF5.


Hope we don't see that
Member Since: August 7, 2010 Posts: 0 Comments: 1933
If brick buildings leveled is EF4 damage, then what is EF5 damage?

Powdered bricks?
No bricks at all?
Member Since: August 13, 2005 Posts: 163 Comments: 25725
Quoting aspectre:
A magnitude5.8earthquake struck near the east coast of Honshu epicentered
34miles at 81.9degrees(E) from FukushimaDaiichi

The lone red dot represents centralTokyo.

Lest we forget, TEPCO wants to shore up reactor#4's cooling pool (loaded with recently hot fuel rods) with support columns lest a quake causes the structurally damaged building to drop that pool from its high perch to the ground.

I saw yesterday that #4 had sprung a new leak. Do you know if that's fixed? I also saw that TEPCO had given up on the idea--mentioned a few days ago--to completely superflood two of the reactors, as their engineers told them this could cause a possible collapse of the entire containment structure.
Member Since: November 8, 2009 Posts: 4 Comments: 13455

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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.