Killer twisters likely among largest, strongest

Apr 29, 2011 By RANDOLPH E. SCHMID and KRISTI EATON , Associated Press
Killer twisters likely among largest, strongest (AP)
A tornado moves through Tuscaloosa, Ala. Wednesday, April 27, 2011. A wave of severe storms laced with tornadoes strafed the South on Wednesday, killing at least 16 people around the region and splintering buildings across swaths of an Alabama university town. (AP Photo/The Tuscaloosa News, Dusty Compton)

Some of the killer tornadoes that ripped across the South may have been among the largest and most powerful ever recorded, experts suggested, leaving a death toll that is approaching that of a tragic "super outbreak" of storms almost 40 years ago.

"There's a pretty good chance some of these were a mile wide, on the ground for tens of miles and had wind speeds over 200 mph," said Harold Brooks of the National Severe Storms Laboratory in Norman, Okla.

It may have been a single long-ranging twister that battered Tuscaloosa, Ala., and then covered the 60 miles to Birmingham, Brooks said.

Only 1 percent of twisters reach the most powerful readings, but Brooks thinks several of those that left death and destruction in Alabama and five other states Wednesday fall into that category.

That speculation hasn't been confirmed yet, but if it is, it's no wonder so many homes were flattened and scores were killed.

This video is not supported by your browser at this time.
This video is from the EF4 tornado that went through Tuscaloosa, AL on 4/27/11.

Most tornadoes are weak, so most reasonably built structures survive them. The typical tornado is on the ground for a couple of miles and is a couple hundred yards wide with half the of the storms that barreled through the region on Wednesday.

It was the deadliest day for tornadoes since a series of twisters killed more than 300 people in 11 states in 1974, Brooks added. The death toll from Wednesday has surpassed 250 and is rising. The worst day in recorded history for storm fatalities is March 18, 1925, with 747 deaths.

"A big question is - the tornado in Tuscaloosa and Birmingham, is it the same one? I think they are the same," he said.

Chris Weiss, a tornado expert at Texas Tech University, said the storm that spawned that tornado formed in Mississippi and "lasted over 300 miles, and even for a super cell that's pretty long."

Tornado outbreaks happen just about every year somewhere in the country. But this time conditions were just about perfect for the series of powerful storms, explained Jerry Brotzge, a senior research scientist at the Center for Analysis and Prediction of Storms at the University of Oklahoma. He noted that a deadly tornado in Oklahoma in 1999 also was almost a mile wide.

Brooks noted there was a trough in the mid-levels of the atmosphere over the western U.S., with a strong jet stream coming across the southern U.S. A trough to the west means winds blowing to the south, turning and then moving back north at the same time a powerful jet of wind blows from the west above.

And that, explained Brotzge, results in an area "to the east of the trough where you have warm, moist southeast winds at the surface and strong dry winds from the west above ... that creates the perfect scenario for strong thunderstorms" and tornadoes.

Why was there such an active weather pattern?

"Causes are always difficult to assign," Brooks said. "A little bit has probably been the weakening La Nina in the Pacific, but not all weakening La Ninas are associated with lots of tornadoes, and we get lots of tornadoes in other situations as well."

La Nina is an unusual cooling of the water in the tropical Pacific Ocean that can change weather patterns around the world. The federal Climate Prediction Center said last month that La Nina conditions were weakening but could continue to affect weather for months.

Weiss said there is no scientific consensus on whether climate change played a role in this series of powerful storms. "The problem is trying to relate a climate signal to a specific weather event is always dangerous," he said.

Deaths from twisters have been declining in recent years because of improved forecasts and increased awareness of them by people living in tornado-prone areas, especially in smaller and rural communities.

While most Americans live in cities, urban areas actually cover only a relatively small percentage of the country. The result is that tornadoes occur more often in rural, sparsely populated areas.

That's led some people to believe twisters don't strike cities. But the National Climatic Data Center in Asheville, N.C., calls that a myth: "Tornadoes have hit several large cities including Dallas, Oklahoma City, Wichita Falls, St. Louis, Miami and Salt Lake City. In fact an urban tornado will have a lot more debris to toss around than a rural twister."

While May is historically the busiest month for tornadoes, they surge sharply upward in April as warm weather begins setting in and dry western air collides with warm moist conditions moving north from the Gulf of Mexico.

Indeed, the biggest tornado outbreak on record occurred April 3-4, 1974 when 147 confirmed twisters touched down in 13 states, claiming more than 300 lives in the United States and Canada.

However, April 1957 was more like this year, recording several days with large numbers of deadly twisters, said Brooks. By contrast April 1974 was a relatively average month, he said, with one "ridiculous" day.

The extraordinary swarm of tornadoes battering the country this month seems bent on proving Mississippi State University professor Grady Dixon's point - Tornado Alley is a lot bigger than people thought.

While that's traditionally seen as a north-south swath of the nation from the Dakotas to Texas with a second twister center - Dixie Alley - extending across the South from Arkansas to Georgia, Dixon argues they are really one big tornado risk area.

"Our goal is to show that there really are no separate regions, it's all one large risk area that's connected," Dixon said, describing a study scheduled to be published in the Bulletin of the American Meteorological Society.

And the near record number of reported this month has obligingly swept across both "alleys."

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_nigmatic10
1 / 5 (3) Apr 29, 2011
Just a reminder of the unusual jet stream pattern seen this winter/spring and the possibility it played a part in this story.
Moebius
1.6 / 5 (7) Apr 29, 2011
I predicted this stuff happening 20 years ago and it will get much worse in the next 20. It was obvious to me years ago that the effect of our activities would be to throw the weather into chaos. To make an electronic analogy we have added positive feedback to a stable system like an amplifier and it has gone into oscillation. It will oscillate until we remove the feedback which is our increasing activities and allow the system to stabilize again. Of course being the unintelligent species we are this won't happen willingly, it will have to be forced on us by the dire effects we cause. Those that know can't do anything and the skeptics will have to have their face rubbed in it repeatedly before they finally believe. And when it finally is forced on us we may not like the new state of equilibrium we generate.
rgwalther
2.6 / 5 (5) Apr 29, 2011
* And the massive tornado outbreaks in 1926, 1974 etc, etc were what part of your 'positive' feedback? 'Pre-positive, anticipatory' or maybe 'chronologically negative pre-amplification'?
* And the pre-1950 lack of ANY type or wide capability to observe much less identify tornado occurence provides which part of your calculation parameters?
* And the weather satellite emergence starting in the 1970's validates unsupported and unprovable theories by providing what evidence of tornadoes prior to the availability of evidence?

Global warming and climate change have now replaced the various gods as the explanation for anything. After all this is science not religion...right?
freethinking
1 / 5 (9) Apr 29, 2011
I like the article, it basically says even though no scientific consensus can show man caused these storm, they will try to blame global warming, or is it now global cooling, oh its climate change (oh whatever)lets just say man cause these things.
JimB135
not rated yet Apr 29, 2011
Whatever the cause these things are monsters. One certainly has to be amazed at the power of mother nature. The person shooting the video certainly was. Near the end of the video it sounds like he is in a state of terrorized shock.
winthrom
not rated yet Apr 29, 2011
In 1972 I had the pleasure of meeting one of the first people to forecast a tornado: Robert Miller. He was working (as I was) at Air Force Global Weather Central (AFGWC) in Omaha, Nebraska. I was a brand new (wet behind the ears) forecaster and Mr Miller was a civilian in charge of Air Force Weather forecating. The story of what Air Force Captain Robert C. Miller and Major Ernest J. Fawbush accomplished can be found here:
http://www.outloo...rn50.htm
axemaster
4.5 / 5 (8) Apr 29, 2011
I like the article, it basically says even though no scientific consensus can show man caused these storm, they will try to blame global warming, or is it now global cooling, oh its climate change (oh whatever)lets just say man cause these things.

Actually, they said nothing of the kind. Here's what they actually said:

Weiss said there is no scientific consensus on whether climate change played a role in this series of powerful storms. "The problem is trying to relate a climate signal to a specific weather event is always dangerous," he said.

Always good to see you irrational idiots are out and about.
Skeptic_Heretic
4.6 / 5 (11) Apr 29, 2011
I like the article, it basically says even though no scientific consensus can show man caused these storm, they will try to blame global warming, or is it now global cooling, oh its climate change (oh whatever)lets just say man cause these things.

You don't even read the articles. Sometimes I wonder if you're even capable of understanding what you read at all.
GSwift7
2.8 / 5 (8) Apr 29, 2011
Well, there's another story here on physorg which says it a lot more clearly. The above comment is a little vague. However, quibbling over wording of what was probably an informal telephone interview is getting way too carried away. But it is kinda funny. "Where you speeding? Well officer, there's no scientific concensus that I wasn't" lol.

My brother was right in the middle of the storms. He lives in Huntsville. His house is okay, but his garage door got blown out. Since they will be out of power there for at least a few days, my brother and his wife and kids decided to come here to SC and stay with mom and dad. They had trouble getting gas to get out of town. No electricity means no gas pumps. His tropical fish are gonna die, but he came out of the storms in good shape compared to many others who live near him.
trekgeek1
1 / 5 (1) Apr 29, 2011
Well, there's another story here on physorg which says it a lot more clearly. The above comment is a little vague. However, quibbling over wording of what was probably an informal telephone interview is getting way too carried away. But it is kinda funny. "Where you speeding? Well officer, there's no scientific concensus that I wasn't" lol.

My brother was right in the middle of the storms. He lives in Huntsville. His house is okay, but his garage door got blown out. Since they will be out of power there for at least a few days, my brother and his wife and kids decided to come here to SC and stay with mom and dad. They had trouble getting gas to get out of town. No electricity means no gas pumps. His tropical fish are gonna die, but he came out of the storms in good shape compared to many others who live near him.


What? He left perfectly delicious tropical fish behind to go to SC? Not the choice I'd have made. But then again, I'm a survivor ;)
freethinking
1 / 5 (8) Apr 29, 2011
SH, you make me laugh. Progressives have no humor.

How can you tell a progressive from a conservative? Tell them someone needs help. The conservative will ask how they can help, the progressive will yell, tax the rich, tax the rich.
Skeptic_Heretic
5 / 5 (1) Apr 29, 2011
If you think
I like the article, it basically says even though no scientific consensus can show man caused these storm, they will try to blame global warming, or is it now global cooling, oh its climate change (oh whatever)lets just say man cause these things.
is humorous, then no, we do not share a sense of humor. Your further commentary is just inane.
madrigal
5 / 5 (1) Apr 30, 2011
It is impossible to prove one way or another whether a freak weather event has anything to do with AGW but put them all together...........
MarkyMark
5 / 5 (1) Apr 30, 2011
SH, you make me laugh. Progressives have no humor.

How can you tell a progressive from a conservative? Tell them someone needs help. The conservative will ask how they can help, the progressive will yell, tax the rich, tax the rich.

Yea great recovery there...NOT!!!

Next time read the article.
patnclaire
1 / 5 (1) Apr 30, 2011
Next Skeptic Heretic and Moebius will be citing Damnation Alley as a source of what is to come. How about the original Voyage To The Bottom of The Sea?
Skeptic_Heretic
not rated yet May 01, 2011
Next Skeptic Heretic and Moebius will be citing Damnation Alley as a source of what is to come. How about the original Voyage To The Bottom of The Sea?

Where in the world did you get that idea?
TheGhostofOtto1923
1 / 5 (4) May 01, 2011
SH, you make me laugh. Progressives have no humor.

How can you tell a progressive from a conservative? Tell them someone needs help. The conservative will ask how they can help, the progressive will yell, tax the rich, tax the rich.
Once again science adds clarity:

"In line with many previous studies, it found no difference between the ethical behavior of believers and nonbelievers. But those who believed in a loving, compassionate God were more likely to cheat than those who believed in an angry, punitive God.

"The take-home message is not whether you believe in God, but what God you believe in"
http://articles.l...20110430

-According to this study, religionists are actually atheists with a lot of extra baggage and trappings, behaviorally speaking that is; except for the ones who believe god forgives sins, who may exhibit an enhanced tendency to cheat. Which does make a lot of sense, doesnt it?
rgwalther
not rated yet May 03, 2011
Ancient Otto, I believe in the Church of Jesus Christ the Utterly Indifferent (Reformed), not the heretical early CJCUI and its devil worshipping, blashpemous idolators!
panorama
5 / 5 (1) May 03, 2011
I remember renting the movie "Twister" when it came out on VHS (dating myself here...) and under the MPAA Rating it explained that it was rated PG for "Intense depiction of very bad weather".
ryggesogn2
1 / 5 (3) May 03, 2011
Want you and your house to survive a tornado (or fire, or hurricane, or earthquake) and save energy? Build an insulated, reinforced concrete dome house. There are many styles and sizes to choose from.
http://www.monoli...-tornado]http://www.monoli...-tornado[/url]
Want you and your house to survive a tornado (or fire, or hurricane, or earthquake) and save energy? Build an insulated, reinforced concrete dome house. There are many styles and sizes to choose from.
http://www.monoli...-tornado]http://www.monoli...-tornado[/url]
http://www.monoli...ed-homes
rgwalther
5 / 5 (2) May 03, 2011
for "Intense depiction of very bad weather".


Actually 'Twister' was a bad depiction of very intense weather...