NOAA: Preliminary analysis of April 27-28 tornado outbreak makes it the 3rd deadliest so far

National Severe Storms Laboratory (NSSL) map below shows tornado tracks logged by NEXRAD Doppler Radar

Bright reds, oranges and yellows show tracks of where rotation was strongest as detected by NWS Doppler radars during the April 27, 2011 tornado outbreak. - click to enlarge

NOAA’s preliminary estimate is that there were 211 tornadoes on April 27-28, 2011.

  • During the multi-day period of April 26-28, The National Weather Service (NWS) estimates there were a total of 288 tornadoes.
  • NWS issued outlooks five days in advance, watches hours in advance, and tornado warnings with an average lead time of 24 minutes. NWS issued warnings for more than 90 percent of these tornadoes.
  • The largest previous number of tornadoes on record in one event occurred from April 3-4, 1974, with 148 tornadoes.

Current media reports indicate the death toll is 318 people, and rising. This makes the event the third deadliest tornado outbreak on record.

  • The April 27-28, 2011, tornado outbreak is the deadliest since the March 21, 1932, tornado outbreak that had 332 fatalities.
  • Based on combined NOAA, historical research records and current fatality estimates, the April 27-28, 2011, tornado outbreak ranks 6th in single day total fatalities in the United States history. The historic research records extend back to 1680.
  • The deadliest single tornado on record was the Tri-State Tornado (Mo., Ill., Ind.) on March 18, 1925, when 695 died.
  • Based on combined NOAA and historical research records, the deadliest single day for tornadoes was March 18, 1925, with 747 fatalities across 7 states (including the Tri State Tornado).

Monthly tornado weather summary

http://www.spc.noaa.gov/climo/online/monthly/1104_map_torn.gif

Data is preliminary and subject to revision

Month of April 2011 (and record monthly) tornado statistics 

NWS’s preliminary estimate is that there have been more than 600 tornadoes thus far during the month of April 2011.

  • The previous record number of tornadoes during the month of April was 267 tornadoes set in April 1974.
  • The previous record number of tornadoes during any month was 542 tornadoes set in May 2003.
  • The average number of tornadoes for the month of April during the past decade is around 160.

2011 Year-to-Date (and record annual) statistics

NWS’s preliminary estimate is that there have been 835 tornadoes so far this year.

  • The previous yearly record number of tornadoes was set in 2004 with 1,817.
  • May is historically the most active month for tornadoes.

Source: http://www.noaanews.noaa.gov/april_2011_tornado_information.html

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41 thoughts on “NOAA: Preliminary analysis of April 27-28 tornado outbreak makes it the 3rd deadliest so far

  1. Not wanting to be disrespectful. but death toll is a meaningless measure of the intensity of a Tornado season, as it is purely down to chance if a Tornado forms over a built up area, thousands could form, all over open areas with nobody being harmed.
    There have been over 600 Tornados this April, more than twice the previous April record, surely this can be seen that something significant is occuring in the weather patterns that create these events.

  2. Seems that climate is reverting back to that of the mid 70’s 😉
    Queensland floods, USA tornados..etc

  3. jcrabb says:
    April 29, 2011 at 8:48 pm
    There have been over 600 Tornados this April, more than twice the previous April record, surely this can be seen that something significant is occuring in the weather patterns that create these events.

    …or that something has occurred. Whether it is a sudden, ongoing and permanent fixture in the tornado world will simply require more observation…not to outdo James Hansen, but I’ll bet it’s just a spike in natural variabilty, from a cold spring in a La Nina year.

  4. Mike Bromley the Kurd says:
    April 29, 2011 at 9:28 pm
    “…or that something has occurred. Whether it is a sudden, ongoing and permanent fixture in the tornado world will simply require more observation…not to outdo James Hansen, but I’ll bet it’s just a spike in natural variabilty, from a cold spring in a La Nina year.”
    According to this there is an increasing trend in the number of Tornados, so something on top of Natural variability is occuring.
    http://www.artemis.bm/blog/2011/04/28/u-s-midwest-tornado-and-severe-weather-outbreak-continues-to-break-records/
    As to suggestions that this upward trend is solely a product of improved detection, if older systems of detection were so bad, how was it possible to detect 267 in April 1973 and 210 in 1956, obviously the detection capabilities existed, just not the Tornados in other years.

  5. Ive been wondering if the fires in Texas might be creating a worse than normal tornado season. Hot air, smoke and water vapor rising.. ect.. when I look at the SSEC composite satellite for that day it seemed like the bulk of the system was puffing right out of NE Texas. Just a wondering on my part though.

  6. It would be interesting to graph that trend against population density.
    Also against the gradual improvement of detection instrumentation.

  7. ps, jcrabb
    Your last paragraph is really clutching at straws. How do you know that modern instrumentation would not have yielded much higher numbers.?

  8. Dear Anthony
    There is something that is not getting any press in this event. There was ANOTHER deadly tornado in Alabama approximately 12 hours after the Tuscaloosa event. The small town of Cordova Alabama was wiped off the map by this 5 am twister.
    I have this personally verified by people that I have known my entire life so I am sure that there is no mistake in this.
    There has been a bit of help and the Alabama National Guard has been deployed but no outside help beyond the county has been provided as all of the coverage is of Tuscaloosa, Concord, Pleasant Grove and other Jefferson county locations. Cordova is on the edge of Walker County.
    I just want to see this out there so maybe some one in the media will pick up on it.
    Thanks, this is my home area and these are mostly country folk and they don’t know what to do to get help there.
    REPLY: The TV Station ABC 33/40 in Birmingham has video they aired, people must know Anthony

    Here’s the tornado footage

  9. Andy G55 says:
    April 29, 2011 at 11:51 pm
    ps, jcrabb
    “Your last paragraph is really clutching at straws. How do you know that modern instrumentation would not have yielded much higher numbers.?”
    Sure, but that would make 1973 an incredibly bad year, as new detection methods since the nineties seem to detect very roughly 30% more Tornados (assuming no trend).
    People claim that the number of F3-5 Tornados have decreased since the 70’s, so if that data is acceptable then the total number of Tornados data should be acceptable.

  10. The data is inconsistent and cannot give a clear picture. You are comparing NEXRAD data to 1930s technology where it’s quite likely that a lot of tracks were not recorded because of lower population density, and technology deficiencies. Who cares if a bunch of trees were knocked over, or knows when for that matter. It’s just the best we can do.
    Like the NOAA folks do with hurricanes, the data from differing technology eras just cannot be reliably consistent. Take a look at what 1930s satellite data looks like, compared to today’s tiny-tim detectors. For instance the 1900 Galveston hurricane was detected when someone yelled “thar she blows” … and by most accounts this was the most deaths ever for a hurricane.
    We should just marvel at what technology has provided… Not really a critique, but we owe it to people to point out how technology has likely changed the analysis, and the results. Is it wrong to say we don’t know?
    Now can we discuss the accuracy of CO2 detectors in 5000 BC.

  11. jcrabb:

    People claim that the number of F3-5 Tornados have decreased since the 70′s, so if that data is acceptable then the total number of Tornados data should be acceptable.

    This is not necessarily true. Because the F3-F5s would produce higher levels of damage and would likely have longer paths, their probability of detection would be higher than for weaker tornadoes and therefore more likely to be counted even without satellite technology.
    The same effect is evident in hurricane counts where even the weakest weather system that may reach hurricane status for only a short period of hours would be counted today, but missed before the current technology came into existence.

  12. tarpon wrote:
    “…Take a look at what 1930s satellite data looks like, compared to today’s tiny-tim detectors.”
    Yeah, especially since the first successful weather satellite wasn’t launched until 1960 😉
    As for radar, the NWS WSR-57 (1957) was built w/tube technology & the WSR-74(1974) had transistor technology but were both reflectivity only (no doppler). The WSR-88 (1988) is the NEXRAD system with computer processing of reflectivity, doppler & other associated products.
    Jeff

  13. Did anyone notice that Tornado Alley has moved to the south and east, at least for this outbreak. It seems that the heat-energy to fuel the storms is not longer present in the Great Plains. That would seem to indicate a cooler/drier Plains area. Is that true?

  14. Hey Anthony,
    With all the hullabaloo about tornado’s being linked to “global warming”, I keep remembering that you posted back about a month ago that this was going to be a big tornado season. Do you have a link to that post?
    Thanks

  15. I second pkatt’s “…wondering if the fires in Texas might be creating a worse than normal tornado season. Hot air, smoke and water vapor rising.. ect……”
    Also the Texas fire smoke providing nuclei for water droplets? Also, some of the warmest Carribean Sea temps,
    http://climateprogress.org/2011/04/27/midwest-deluge-record-gulf-sea-surface-temperatures/
    not that I know if the resultant moisture also travels North. I later have learned that the warm sea temps are assuciated with the La Nina
    .

  16. Thanks to Anthony and Dennis Wingo for the footage on the Cordova AL disaster. We must try to help these people.

  17. “vukcevic says:
    April 30, 2011 at 1:05 am
    it is possibly sign of climate change, not warming but cooling!”
    This seems to be very true! According to the latest numbers at UAH, we are below the 30 year average for temperatures so far in 2011. And according the the latest numbers at HADCRUT3, 2011 so far is the coldest year since 1996: http://www.cru.uea.ac.uk/cru/data/temperature/hadcrut3gl.txt

  18. jcrabb:”According to this there is an increasing trend in the number of tornadoes, so something on top of Natural variability is occuring.”
    You’re kidding aren’t you? Just because there is increasing trend doesn’t mean it is beyond natural variability. Then in the paragraph you argue against yourself by saying that there were a lot of tornadoes in the 1970s.

  19. Just a theory, the one oil platform that spilled billions of gallons of oil/petrol into the Gulf of Mexico. That wasn’t the only oil platfrom mining oil was it?…What if our mining of oil is contributing to the warmer mantle/seas?…What does oil do anyways?…Isn’t it used to keep machinees from overheating?…hmmm.

  20. Preamble: I’m sceptical regarding AGW (which means I’m undecided, although I’ll admit the weight of the argument currently appears to be against the hypothesis). I have no vested interest in who is right, I’m just interested in the science. Hence this question, as I’ve read sceptical views and pro-AGW views on the recent tornados, and both seem to be saying different things based on the same observations.
    I’ve asked the opposite question on Joe Romm’s blog, although it’s currently in moderation.
    Elsewhere on WUWT I read that the explanation for the high number of tornados this year was due to warm air fro the gulf of mexico (I think) meeting cold air from La Nina, causing high winds and these formed into tornados. The implication is that it’s La Nina’s fault, and nothing to do with AGW.
    However, is it not the case that the temperatures in Alabama were unseasonably high, and if so didn’t this exacerbate the warm/cold air effect? Hence isn’t it possible that this is in fact an AGW effect? (or a GW effect, at any rate).

  21. And then there is the totally unknown effect of a quiescent sun. It does seem like cooling is more likely to be the issue than warming.

  22. This nfrom MikeSmith a couple mof days ago:
    “I have placed arrows pointing to the temperatures in 1884 (the “Enigma Outbreak” which killed as many as 1,200 in the South), the 1936 Tupelo/Gainesville tornadoes (which killed 800+), the “Superoutbreak” of tornadoes in 1974, and Wednesday’s. Note that these tornado outbreaks — which killed even more people — all occurred with cooler atmospheric temperatures.”
    Above they mention 1925 and 1932 outbreaks. So is it the 3rd, 4th or 5th most deadly. Clarification anyone.

  23. Derek Sorensen says:
    April 30, 2011 at 2:01 pm
    “However, is it not the case that the temperatures in Alabama were unseasonably high, and if so didn’t this exacerbate the warm/cold air effect? Hence isn’t it possible that this is in fact an AGW effect? (or a GW effect, at any rate).”
    Mississippi and Alabama are bathed by warm blasts from the Gulf all the year. A cold blast in north Alabama might last a week at most and is followed by balmy weather from the Gulf. The temperatures in the Deep South for the last week have been normal to cool. (I am not a meteorologist but am an expert in the region.)

  24. Also see:http://online.wsj.com/article/SB10001424052748703655404576293150621087550.html
    That gives us 1925, 1927, and 1932 for extreme weather events, as temperatures rose from a low ca 1910 to a high ca 1940. In past 60 year cycles the upsides seem to take longer than the declines (cycles are quite asymetric), and we are now in a down phase, so kaybe3 temps not unlike that late 1920s period. Does anyone know what La Nina and the PDO looked like in 1925-1932.

  25. Hello Derek,
    Something to put into this, noticed the repeated blocking weather in England, right now sustained east winds, also close to drought. I suspect the general global weather patterns have switched mode, probably a year or so ago. (try PDO, 15 to 35 years at a time)
    http://www.nwfsc.noaa.gov/research/divisions/fed/oeip/ca-pdo.cfm
    No-one actually knows what is going on, various guesses.
    There is a tornado belt. Plenty is known, real weather people know about that. The conditions necessary altered by other factors? That is the fuss. Loudmouths declaring causal before they can possibly have data, done any work, etc., ho ho.
    Look back over a few days at WUWT articles, some useful plots about general conditions. (one even mentions blocking Alaska way

  26. @TimC – good to see you, haven’t spoken for a while.
    The question isn’t really about tornados, but about the idea that Alabama is hotter atm than it ought to be, which in turn caused the tornados. I’ve read the other WUWT posts (referred back to them) but they don’t really address that fundamental question.
    Don’t mean to be picky, just trying to sort the wheat from the chaff.

  27. May I make a recommendation to all who take videos or photos of damage caused by a tornado? Please provide perspective. Please do not take a photo that shows nothing but damage. Such a photo contains very little information, unless the viewer is familiar with the scene before the damage occurred. Frame the photo by showing the undamaged area on both sides. That gives perspective and provides invaluable information. Now the viewer can estimate how extensive the damage was. For those taking video, the advice is the same with the addition that, if you are lucky enough to follow a storm track in a helicopter, include a border of undamaged area on both sides of the track. Otherwise, no one can make a reasonable estimate of the damage. If the damage is great enough, include just one border of undamaged area.
    Looking at videos and photos provided by professional news organizations over the web, I see that all of them make the same errors. Amazing! The only way to get some perspective on the damage caused by a given tornado is to find its path on a website that provides a “photo-realistic” map of the area.

  28. ” Theo Goodwin says:
    April 30, 2011 at 3:02 pm
    Mississippi and Alabama are bathed by warm blasts from the Gulf all the year. A cold blast in north Alabama might last a week at most and is followed by balmy weather from the Gulf. The temperatures in the Deep South for the last week have been normal to cool. (I am not a meteorologist but am an expert in the region.)”

    Thanks, Theo, that seems to answer the question. Don’t know why I overlooked your reply last night.

  29. On the Texas fires subject I would add: There has been a large number of big not so high altitude volcano eruptions closer to the equator lately. Ecuador, Philippines, Japan, Indonesia and New Zealand. Couple that with the regularly spewing high fliers in Kamchatka and Eyjafyalla solar dimming in the north and you have a brew for sharpened temperature gradients that cause disastrous mixing when the air masses move.

  30. The comment above makes an interesting point. If tornado tracks have moved South this year, and this can be viewed within an historical setting of tracks, CO2-driven climate change seems less of a driver than natural weather pattern variations. The notion that the South is 1 F warmer and 4% moister would not be a driver of the movement South. For that, one would have to compare the relative strength of the cold front dipping further South, causing the southerly movement of the tracks compared to previous seasons. Wonder what the matching analogue seasons would show regarding track position.

  31. m4570d0n says:
    May 1, 2011 at 10:18 am
    On another forum at WUWT, I explained that my mother’s stories about the day Tupelo was “blown away” by a tornado forms a memorable part of my youth. That disaster was in the neighborhood of 1953.

  32. The picture well illustrates what we went though in the southeast. By my count, my home in Ooltewah, TN, (outside Chattanooga) dodged three tornados; with tornados strikes to the north and south of me and only relatively minor wind damage in my community (mainly trees falling on homes).
    My kids in Huntsville, AL, experienced near continuous tornados warning throughout the day of the storm. My son lives with his mother in and my daughter is a student at UAH. The power has been out in Huntsville since the storm. UAH has given the students the option of taking their grades “as is” and skipping final exams.
    The kids have been though tornados before and are tornado “savvy”. They will go outside to look at them if the doppler radar indicates its relatively safe to do so (i.e., well to the side of the “track”, guided by the noise, and within seconds of a safe spot); but, my daughter said this storm was so different that when she stepped outside the hair stood up on the back of her head and she immediately sought refuge. Both kids said that the warnings lasted so long that the local tornado sirens backup batteries eventually gave out.
    Relatives in Muscle Shoals, AL, indicated that at least two towns just to the south of them were completely wiped out. The ‘Shoals area has become a place of refuge. My daughter made an emergency trip to the there to resupply her friends in Huntsville with food, ice, radios, cooking stoves, and propane.
    Since I have power, both my kids abandoned Huntsville yesterday (in “convey”) and are now staying with me. On the way, they went through a badly damaged town just outside Huntsville (don’t know which one) where there “there was nothing left higher than 18 inches tall”.
    Regards,
    Kforestcat

  33. Murray says:
    April 30, 2011 at 2:50 pm
    “This nfrom MikeSmith a couple mof days ago:
    “I have placed arrows pointing to the temperatures in 1884 (the “Enigma Outbreak” which killed as many as 1,200 in the South), the 1936 Tupelo/Gainesville tornadoes (which killed 800+), the “Superoutbreak” of tornadoes in 1974, and Wednesday’s. Note that these tornado outbreaks — which killed even more people — all occurred with cooler atmospheric temperatures.”
    Above they mention 1925 and 1932 outbreaks. So is it the 3rd, 4th or 5th most deadly. Clarification anyone.”
    I’m pretty sure those stats are off. The Tupelo/Gainesville event (as mentioned above) resulted in anywhere from 400-500 fatalities, whereas the Enigma Outbreak had no where near 1200 deaths…
    So anyway, its most likely the third deadliest, after the Tri-State event and the Tupelo/Gainesville sequence. This is assuming that all those people still missing are alive, which we all certainly hope to be the case.

  34. …unless that is, the high estimate of the deaths is due to the common disregard for African-American fatalities before the 1940’s and 50’s.

  35. @Tarpon… The hurricane that you speak of was actually detected by a junior meteorologist several days before the actual storm, and he was rebuffed by the senior meteorologists in Galveston. He was right, they were wrong, and as a result of ego, MANY people ended up dying needlessly.

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