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Most of the time, downsloping winds will weaken precipitation and storms as they move into that area. However, I have always heard stories of another tornado that went across Greene Mountain many years ago. It kind of makes me wonder if some of the enhanced and backed low level winds (due to the terrain) might occasionally act to enhance the wind profile in that localized area when a supercell is able to survive the other negative effects.If the surface winds in all other areas are south at 15-20 mph, the winds in southern Greene County may be southeast at 30-40mph with 60mph gusts (for example). I have always wondered what would happen if a supercell would track along that area. Two supercells moved across that area Wednesday night, and both had a significant increase in rotation as they crossed the Camp Creek area.
What I'm caught off guard by is the fact that this article states that there will be more of these outbreaks in the future. Now, correct me if I'm wrong, but aren't these supposed to be once/twice in 100 year events?
Adam: Girls come and go. Weather is constant
Eric (Admin): there's no fornication in meteorology
THis is still the best footage in my opinionhttp://www.youtube.com/watch?v=5sZJBxHiCRs
133 NOUS44 KJAN 051837PNSJANPUBLIC INFORMATION STATEMENT...TORNADO DAMAGE SUMMARY UPDATENATIONAL WEATHER SERVICE JACKSON MS135 PM CDT THU MAY 5 2011...TORNADO FROM NESHOBA COUNTY TO NOXUBEE COUNTY ON APRIL 27TH UPGRADED TO EF-5 BASED ON ADDITIONAL ANALYSIS OF INFORMATION...BASED ON A REVIEW OF DAMAGE SURVEY DATA COLLECTED IN NESHOBA... KEMPER...WINSTON AND NOXUBEE COUNTIES BY METEOROLOGISTS WITH EXPERTISE IN VIOLENT TORNADO DAMAGE ANALYSIS...IT HAS BEEN DETERMINED THAT THIS TORNADO SHOULD BE RATED AS AN EF-5. THE BASIS FOR THE UPGRADE IS FOUNDED UPON SEVERAL OBSERVATIONS:IN TWO LOCATIONS...THE TORNADO ACTUALLY GOUGED OUT LARGE SECTIONS OF THE GROUND. IN ONE SPOT IN NORTHEAST NESHOBA COUNTY...THE GROUND WAS DUG OUT TO A DEPTH OF AROUND 2 FEET OVER AN AREA APPROXIMATELY 25-50 YARDS WIDE AND A COUPLE OF HUNDRED YARDS LONG. SIMILAR GOUGES... ALTHOUGH NOT AS LONG OR DEEP...WERE ALSO OBSERVED IN EXTREME NORTHWEST KEMPER COUNTY. WHILE THE EXACT MECHANISM THAT CAUSED THIS DAMAGE IS UNCLEAR...INDICATIONS ARE THAT THIS TYPE OF GROUND DAMAGE IS TYPICALLY ASSOCIATED WITH THE EXTREME WIND SPEEDS ASSOCIATED WITH EF-5 TORNADOES.IN THE AREA OF NORTHWEST KEMPER COUNTY WHERE THE GROUND GOUGING WAS OBSERVED...THERE WAS ALSO AN AREA WHERE PAVEMENT WAS REMOVED FROM THE GROUND. WHILE THIS TYPE OF DAMAGE CAN BE CAUSED BY TORNADOES OF LESS THAN EF-5 INTENSITY...THE FACT THAT PIECES OF ASPHALT WERE FOUND AT A SIGNIFICANT DISTANCE AWAY...BOTH UPWIND AND DOWNWIND OF THE ROAD...ARGUES FOR EXTREME WIND SPEEDS. SIMILAR TYPE DAMAGE WAS ALSO OBSERVED IN SOUTHWEST NOXUBEE COUNTY.FINALLY...EXTREME VEHICLE DAMAGE OF THE TYPE NORMALLY ASSOCIATED WITH EF-5 TORNADOES WAS OBSERVED. THIS INCLUDED NEW VEHICLES BEING MOVED MORE THAN 100 YARDS FROM WHERE THEY STARTED...AND BEING LEFT IN A NEARLY UNRECOGNIZABLE STATE.THE UPGRADING OF THIS TORNADO TO AN EF-5 MEANS THAT THIS IS THE FIRST EF-5 TORNADO IN THE NWS JACKSON SERVICE AREA SINCE THE CANDLESTICK PARK TORNADO ON MAY 3...1966. ADDITIONALLY...THIS MARKS THE FIRST TIME SINCE STATISTICS HAVE BEEN KEPT THAT TWO EF-5 TORNADOES HAVE BEEN RECORDED ON THE SAME DAY IN MISSISSIPPI...WITH THE TORNADO IN SMITHVILLE ALSO RATED AN EF-5.FOR MORE INFORMATION ON THIS TORNADO...INCLUDING PICTURES AND VIDEO OF THE DAMAGE...PLEASE VISIT OUR WEBSITE AT WWW.SRH.NOAA.GOV/JAN (LOWER CASE) AND CLICK ON THE APRIL 25-27TH TORNADO OUTBREAK LINK IN THE HEADLINE SECTION AT THE TOP OF THE PAGE.COUNTY/PARISH: NESHOBA...KEMPER...WINSTON...AND NOXUBEE BEGINNING POINT: 1 N PHILADELPHIA AT 230 PMENDING POINT: 6 SE MASHULAVILLE AT 300 PMRATING: EF-5MAX ESTIMATED WINDS 205 MPH PATH LENGTH: 29 MILESMAXIMUM WIDTH: .5 MILE FATALITIES: 3 INJURIES: 8 (AT LEAST)SUMMARY OF DAMAGE: THIS TORNADO CAUSED A PATH OF EXTENSIVE DAMAGE IN NORTHEAST NESHOBA,EXTREME NORTHWEST KEMPER, EXTREME SOUTHEAST WINSTON, AND SOUTHWESTNOXUBEE COUNTIES. THE MOST INTENSE DAMAGE OCCURRED IN A SEVERAL MILEAREA FROM EXTREME NORTHEAST NESHOBA COUNTY INTO EXTREME SOUTHEAST WINSTON COUNTY. THE THREE FATALITIES OCCURRED IN NORTHWEST KEMPER COUNTY WHEN A STRAPPED DOWN DOUBLEWIDE MOBILE HOME WAS THROWN A DISTANCE OF APPROXIMATELY 300 YARDS INTO A TREELINE, AND THEN OBLITERATED WITH THE DEBRIS AND FRAMING SCATTERED MANY HUNDREDS OF YARDS DOWN THE PATH. THERE WAS NO INDICATION OF GROUND IMPACTS BETWEEN THE ORIGINAL SITE OF THE MOBILE HOME AND WHERE IT ENDED UP TO INDICATE THAT THE MOBILE HOME BOUNCED EXTENSIVELY AS IT TRAVELED. TWO TRADITIONAL FRAME BRICK HOMES IN SOUTHEAST WINSTON COUNTY WERE COMPLETELY LEVELED WITH ONLY A FEW SMALL PARTS OF INTERIOR WALLS STANDING. NEW VEHICLES WERE THROWN OR ROLLED HUNDREDS OF YARDS BEFORE BEING WRAPPED INTO TREES AND LEFT ALMOST BEYOND RECOGNITION. IN PARTS OF NORTHEAST NESHOBA AND NORTHWEST KEMPER COUNTIES, THERE WAS VERY HIGH END TREE DAMAGE WITH EXTENSIVE DENUDING AND DEBARKING OF TREES, ALONG WITH AREAS WHERE THE GROUND WAS SCOURED OUT TO A DEPTH OF TWO FEET IN PLACES, AND ASPHALT WAS SCOURED OFF PAVEMENT.THE NWS WOULD LIKE TO THANK THE METEOROLOGISTS THAT REVIEWED THE DAMAGE INFORMATION TO ASSIST IN MAKING THIS RATING...AND ALSO THE EMERGENCY MANAGERS WHO HELPED IN GATHERING ALL OF THIS INFORMATION.$$AEG
I found this tidbit from JAN today. I have not seen it posted yet, but mods feel free to delete if it is a repost:
Apologies for the large bump...but some info I wanted to share.This past week was the National Severe Weather Workshop in Norman OK. Like the Severe Storms Symposium at MSU this weekend...a LOT of focus on April 27. Great presentations from both I'm already hearing about...and I suspect we'll hear/see more from this in the coming days/weeks.One standout though...Jim LaDue at NOAA/WDTB...gave a great talk about the difficulties in going EF4 vs EF5, especially on April 27. He was the national expert at many of the violent tornado sites. He indicated that Tuscaloosa was by far the hardest rating he's had to deal with...and that they were VERY close to going EF5 based on damage at that apartment complex. They actually had three separate teams survey it and 2/3 went high EF4...the other split between EF4 and EF5.What held them back overall...4 DOD indicators of EF5 were not present that were at most other EF5 events. They are (and this is good for future reference): Home debris pulverization, shrubbery debarked (not just trees), ground scouring, and vehicles tossed at long distances. Given this and the split at the apartment complex...they held at EF4.He also indicated the easiest to classify EF5 was Smithville, MS. All DOD indicators were present but what was most apparent was the case of the Ford Expedition being tossed 1/2 mile...slamming into the town's water tower...then being carried an additional 1/4 mile. The clear-cut nature of this made its upgrade the first of all tornadoes from 4/27...just two days after the event.Hopefully this (and other) presentations will be uploaded soon...
Did they ever check to the northeast of Tuscaloosa where radar indicated the tornado intensified over that area? Plus, wouldn't the fact of the density of homes, buildings and trees in Tuscaloosa as compared to most areas normally hit by tornadoes figure into the determination? I would think that with all of the houses, apartments and stores that were so close together and destroyed that there was no way to have swept slabs as there was a lot of cross-contamination, so to speak. It's not so hard to have a clean slab when the next house is a hundred yards away. I visited Phil Campbell and Hackleburg a few days after the 27th and it was much easier to see EF-5 damage because here was a house, gone. A couple of hundred feet away, another house unshielded by other structures, gone. In Tuscaloosa it looked like the world's largest dump truck drove through town with the bed up and the back gate open. I doubt they took time to do forensic testing to see if a pile of splinters on a foundation belonged to that house or one of ten others in the immediate vicinity. I suspect if Smithville, Ms was as congested as Tuscaloosa, that truck would have never made it very far before it would have slammed into something else before it got very far, let alone half a mile. As I've seen it pointed out in different ways, rating a tornado is an inexact science. Dr Forbes said he saw lots of examples of EF-5 damage on the 29th. Maybe seeing it get rated a 4 made him reevaluate April 3, 1974. In one of his blogs, he now says many of the tornadoes during that outbreak would have been dropped a notch if using today's standards.
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Topic: Super Outbreak 2011 (April 25-28) (Read 655841 times)
