2011-04-27 MISC: AL,TN,MS,KY,OH,IN,WV,GA

Well, that's a shame. It seems like this episode deserves a real meteorological analysis.

I'm absolutely sure it will get one. This was way too big of an event not to be studied. You will see many academic and non-academic articles published on this event in the next few years.
 
Smithville tornado videos

I'm not sure what people think of posting video in these kind of threads as there doesn't seem to be any discussional value in mine other than the interesting aspect that there seems to be very few clips of the Smithville tornado, and none of Hackleburg as it was near that community. I haven't seen these posted here:

http://www.youtube.com/watch?v=5ku9NRDNOfc As the tornado was reportedly over Smithville.

http://www.youtube.com/watch?v=YVBzaPhLn2Q Peculiar surveillance-video from the Smithville PD, with a camera flying away with the carport.
 
The NOAA's current clearinghouse page for the event at this time shows 197 tornadoes surveyed.

I'm not sure it's above board to insist the Super Outbreak was worse even if there were a larger number of tornadoes within a 24 hour period, just for that reason alone. I don't believe the Super Outbreak produced tornadoes continuously over a three-day period. As a total event, April 25-27, 2011 outbreak is unquestionably worse. I don't see how there's a reasonable debate. "Within 24 hours" is arbitrary and meaningless.

The Super Outbreak also featured 6 F5 tornadoes and 24 F4 tornadoes. As best as I can determine, using the preliminary data that is available, the recent April 26-28 event produced 2 EF5 and 11 EF4 tornadoes. Both are quite obviously extreme outbreaks, both in terms of total tornadoes and percentage of all tornadoes that were violent. But considering the Super Outbreak produced a considerably higher number of violent tornadoes in a much shorter time frame, I don't see how it is "unreasonable" when others argue that it is still the most intense tornado outbreak on record. They certainly have valid reasons and a valid argument.

Also, I still don't think we will know precisely which outbreak has the highest overall tornado count until the data has been completely and thoroughly sifted through and entered into the NCDC database. While we can say there were 197 tornadoes within a 3 day period, I still have unresolved questions about whether this event was a continuous outbreak or not. I subscribe to the Grazulis method (which seems to be the accepted standard) that states for a tornado outbreak to be considered a continuous event that first, the tornadoes be produced by the same general weather system and secondly, that there not be a gap of 6 hours or more between tornado touchdowns during the event. At this point, I really don't know if the April 26-28 outbreak meets this criteria. And again, we probably won't until all of the tornado data (including times of touchdowns) make it into the official database. Only then will we be able to determine if this was one humongous, continuous outbreak that surpasses 4/3/74 in numbers, or if it was broken down into two or more separate events. But considering just how rare it is to have a legitimate "continuous" outbreak that spans 3 days or more ( I can only recall one off the top of my head---November 1992), I'm not quite ready to bump the 4/3/74 event down to #2 on the largest outbreaks list just yet.
 
Sickening birds-eye view of the tornado going through Tuscaloosa.... shame on those people who were cheering it on too.

 
The Super Outbreak also featured 6 F5 tornadoes and 24 F4 tornadoes. As best as I can determine, using the preliminary data that is available, the recent April 26-28 event produced 2 EF5 and 11 EF4 tornadoes. Both are quite obviously extreme outbreaks, both in terms of total tornadoes and percentage of all tornadoes that were violent. But considering the Super Outbreak produced a considerably higher number of violent tornadoes in a much shorter time frame, I don't see how it is "unreasonable" when others argue that it is still the most intense tornado outbreak on record.
The number of tornadoes should not be used to define the impacts of the outbreak, but rather the total area covered by tornado damage. Although we have yet to see those numbers, it is possible that the area covered by damage on 27 April 2011 may exceed that covered in 3-4 April 1974. In addition, the area covered by strong and violent damage is important, along with the population densities, land use, and demographic data affected by the tornadoes.
 
In terms of total path length of violent tornadoes,

Super Outbreak
F-4: 865.9 miles
F-5: 283.6 miles

Late April 2011 Outbreak
EF-4: 597.8
EF-5: 147.6

based on Wiki pages
 
Has the Smithville tornado been "connected" to any other paths, yet? I find it hard to believe that such a violent tornado had such a short path length:

http://www.srh.noaa.gov/news/display_cmsstory.php?wfo=meg&storyid=67427&source=0

PATH LENGTH: 2.82 MILES

Given the forward speed of the storms, it could only have been on the ground for three minutes at that path length. That brief of an EF5 tornado just does not compute, especially given the number of much longer-track EF4s and EF3s.

Edit: Ah, here we go:

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE MEMPHIS TN
755 AM CDT MON MAY 2 2011

...UPDATE TO PRELIMINARY EF-5 DAMAGE TORNADO IN MONROE COUNTY
MISSISSIPPI...

BASED UPON FURTHER EXAMINATION OF SATELLITE IMAGERY WHICH
DEPICTED TREE SCARS /KNOCKED DOWN BY THE TORNADO/ AND OTHER
GROUND SURVEY EVIDENCE...THE NATIONAL WEATHER SERVICE OFFICE IN
MEMPHIS IN COORDINATION WITH THE NATIONAL WEATHER SERVICE OFFICE
IN BIRMINGHAM HAS CONNECTED THE SMITHVILLE MS AND SHOTTSVILLE AL
TORNADO DAMAGE SEGMENTS. THIS PUBLIC INFORMATION STATEMENT
PROVIDES UPDATED INFORMATION ON THE SECTION OF THE SEGMENT FROM
SMITHVILLE MS TO NEAR SHOTTSVILLE AL.

* COUNTY/COUNTIES: MONROE

* LOCATION/TIME OF EVENT: SMITHVILLE AT 344 PM CDT ON APRIL 27 2011

* BEGINNING POINT: 34.0517/-88.4236

* ENDING POINT: 34.1579/-88.1847

* RATING: EF-5

* ESTIMATED PEAK WIND: 205 MPH

* PATH LENGTH: 15.24 MILES /CONTINUES INTO SHOTTSVILLE ALABAMA SEGMENT/

* MAXIMUM WIDTH: 3/4 MILE /WIDENED TO MATCH SHOTTSVILLE TORNADO SEGMENT/

That makes much more sense. They should update the top news link on their homepage.
 
Has the Smithville tornado been "connected" to any other paths, yet? I find it hard to believe that such a violent tornado had such a short path length:

http://www.srh.noaa.gov/news/display_cmsstory.php?wfo=meg&storyid=67427&source=0



Given the forward speed of the storms, it could only have been on the ground for three minutes at that path length. That brief of an EF5 tornado just does not compute, especially given the number of much longer-track EF4s and EF3s.

This was the same supercell that produced what is referred to as the "Shottsville" tornado. I believe it actually lifted prior to touching down again just southwest of Hwy78/I-22 near exit 3. This was my first tornado of the day and was rated EF-3 by BMX.
 
As per the updated PNS I found, they were found to be one tornado.

In the "Note:", I guess BMX does indicate that it was one continuous tornado, yet when you read their summary, they suggest the tornado started with coordinates that are almost a mile across the state line. I know I am splitting hairs with them, but it can be very confusing. I have spent a week reading between the lines trying to connect it all as I am sure they have been too. I have been very overwhelmed by the whole event, so I cannot imagine how they must feel.
 
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"Jesus, help these people in Tuscaloosa."

Excellent view of the Tuscaloosa tornado for over seven minutes, including formation and touchdown. apparently shot from a tripod in the bed of a pickup. Shortly after it touches down, the guy with the camera starts praying for Tuscaloosa. The first 6 minutes are on the supercell approaching Tuscaloosa, and the tornado starts to form around 6:25. Lots of tendrils and secondary vortices spinning off and then getting sucked back in without touching down.

Watch video >
 
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One question that comes to mind when comparing the Super Outbreak with 4/27/11 is the consistency of the ratings. It's probably been debated many times before and I'm not criticizing the surveyors in any way, but I have a hard time believing that on the old rating system we would have just the two EF5/F5 tornadoes from 4/27 and just 11 EF4/F4 tornadoes. It seems some damage indicators that were once F5 are now EF4. Damage from Ringgold and the Tuscaloosa/Birmingham tornadoes certainly seems on par with damage photos of Xenia, Brandenburg or other F5's (even quoted as so by Dr. Forbes on the flyover Tuscaloosa damage). I know they say the difference between F4 and F5 is the most difficult to differentiate, but it's hard to imagine these were not quite as strong as say other F5's which did so much less high end damage, often to a minimal number of structures (Broken Bow, Goessel, Chandler, Oakfield).

Irregardless, like most, I never thought I'd see an outbreak even rival the Super Outbreak.
 
One question that comes to mind when comparing the Super Outbreak with 4/27/11 is the consistency of the ratings. It's probably been debated many times before and I'm not criticizing the surveyors in any way, but I have a hard time believing that on the old rating system we would have just the two EF5/F5 tornadoes from 4/27 and just 11 EF4/F4 tornadoes. It seems some damage indicators that were once F5 are now EF4. Damage from Ringgold and the Tuscaloosa/Birmingham tornadoes certainly seems on par with damage photos of Xenia, Brandenburg or other F5's (even quoted as so by Dr. Forbes on the flyover Tuscaloosa damage). I know they say the difference between F4 and F5 is the most difficult to differentiate, but it's hard to imagine these were not quite as strong as say other F5's which did so much less high end damage, often to a minimal number of structures (Broken Bow, Goessel, Chandler, Oakfield).

Irregardless, like most, I never thought I'd see an outbreak even rival the Super Outbreak.

I think there is some truth to this - namely, if the super outbreak were to occur today, the number of tornadoes surveyed as violent may end up being less; however, this is pure speculation.

Keep in mind, BMX has indicated that they have a nationally renown expert who is still looking over damage. It is possible, given the enormity of the damage caused by the Tuscaloosa/Birmingham storm, that they are still examining it.
 
Third tornado upgraded to EF-5 http://mesonet.agron.iastate.edu/p.php?pid=201105051837-KJAN-NOUS44-PNSJAN This one dug some trenches feet deep along it's path

Wow those were some big trenches. I wonder what caused those. I would imagine some large piece of debris dug along the ground did it, but it would've had to have been a huge piece of something to dig a trench the size it did. If it was due to the tornadic winds themselves, then that's the first I've ever heard of a tornado doing that, and is a testament to how strong that tornado was.
 
I believe the 1997 Jarrell tornado dug a trench along it's path as well, but not that deep. Probably due to it's slow forward speed
 
I know from what I have seen from pictures (I haven't been to that part of damaged area myself) but in Ringgold there are some homes that were wiped clean from their foundation in the Cherokee Valley Road area, and the same is true into Tennessee in Apison.

Both areas were rated EF4 (this was the same tornado, btw).
 
Looking at all of the video, with so much debris, I was wondering if the EF scale can be "skewed" because of what the storm picks up rather than the wind speeds. In other words, when a tornado like the Tuscaloosa one picks up a lot of debris, it wouldn't require as high a wind speed to do a greater amount of damage than the same tornado going through a less industrious area. It would be easier to level a brick house with flying bricks and steel than it would with flying wood given the same speed. Just wondering if that works into the equation when figuring out storm speed and damage.
 
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