2 May 2011

The Most Amazing Storm Survey I’ve Ever Read

Posted by Dan Satterfield

 

EF 4 and EF 5 tornado tracks from April 3, 1974 super outbreak. April 27, 2011 far surpassed this in nearly every category.

A large and deadly tornado, on the ground for 132 miles! This is a little longer than the 130 mile track of the deadly tornado that took a very similar path on April 3, 1974.

Track of EF 4/EF 5 tornado on April 27, 2011. Total path 132 miles. This is one path of many that day.

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
959 PM CDT SUN MAY 1 2011

…LONG TRACK EF-5 TORNADO CONFIRMED ACROSS THE TENNESSEE VALLEY…

THIS IS UPDATED INFORMATION CONCERNING CUMULATIVE STORM SURVEY
INFORMATION OF THE EXTENSIVE DAMAGE INCURRED ACROSS FRANKLIN
AL…FRANKLIN TN…LAWRENCE…LIMESTONE…AND MADISON COUNTIES. THIS
INFORMATION IS THE COMBINED EFFORT BY THE NATIONAL WEATHER
SERVICE…LOCAL EMERGENCY MANAGEMENT…A STORM SURVEY EXPERT FROM
THE UNIVERSITY OF ALABAMA IN HUNTSVILLE AND COLLABORATION WITH A
STRUCTURAL ENGINEER AND SURVEY EXPERT. DETAILED FINDINGS HAVE FOUND
ONE COMPLETE TORNADO TRACK FROM SOUTHERN FRANKLIN COUNTY ALABAMA TO
NEAR HUNTLAND IN FRANKLIN COUNTY TENNESSEE. THE UPDATED INFORMATION
IS AS FOLLOWS:

* EVENT TYPE: TORNADO
* EVENT DATE: 04/27/11

* ESTIMATED PEAK WIND: 210 MPH
* PRELIMINARY RATING: EF-5

* PATH LENGTH: APPROXIMATELY 106.9 MILES (FOR THE HUNTSVILLE CWA –
CONTINUATION FROM MARION COUNTY ALABAMA). TOTAL PATH LENGTH 132.1
MILES.

* MAXIMUM PATH WIDTH: 1.25 MILES

* FATALITIES: UNKNOWN TOTAL
* INJURIES: UNKNOWN TOTAL

FRANKLIN AND LAWRENCE ALABAMA:

Tornado tracks across North Alabama on 27 April. Image courtesy Dave Nadler NWS Huntsville.

FOR THE PURPOSE OF THIS SURVEY, THE PATH BEGAN AT THE SOUTHERN
FRANKLIN COUNTY LINE WITH MARION COUNTY NORTH OF HACKLEBURG. FOR
INFORMATION ABOUT THE TORNADO PATH IN MARION COUNTY…CONSULT
INFORMATION PROVIDED BY THE NATIONAL WEATHER SERVICE IN BIRMINGHAM.

THE SURVEY TEAM TRAVELED THROUGH PHIL CAMPBELL AND WITNESSED
CONTINUOUS SIGNIFICANT DEVASTATION THROUGHOUT THE CITY. PROLIFIC
DAMAGE WAS NOTED FROM THE INTERSECTION OF COUNTY ROAD 51 AND ALABAMA
HIGHWAY 237…TO THE INTERSECTION OF COUNTY ROAD 81 AND COUNTY ROAD
75. WITHIN A 2 MILE CORRIDOR EITHER SIDE OF THE RAILROAD TRACKS THE
DAMAGE WAS SIGNIFICANT. WITHIN THIS CORRIDOR…SEVERAL WELL
CONSTRUCTED HOUSES WERE DESTROYED. ALONG BROWN STREET…BLOCK HOMES
WERE LEVELED TO THE GROUND. ALONG BONNER STREET…MULTIPLE BLOCK
HOMES WERE LEVELED TO THE GROUND WITH THE BLOCK FOUNDATIONS DESTROYED.
A 25 FOOT SECTION OF PAVEMENT WAS SUCKED UP AND SCATTERED. CHUNKS OF
THE PAVEMENT WERE FOUND IN A HOME OVER 1/3 MILE DOWN THE ROAD. THE
DAMAGE IN THIS AREA WAS DEEMED TO BE EF-5.

IN ADDITION…AT LEAST 3 CHURCHES ALONG THE PATH SUSTAINED SIGNIFICANT
DAMAGE. ONE CHURCH IN PHIL CAMPBELL WAS COMPLETELY DESTROYED WITH
ONLY THE SLAB REMAINING. MULTIPLE MOBILE HOMES THROUGHOUT THE PATH
WERE COMPLETELY DESTROYED…AND THEIR MANGLED FRAMES WERE TOSSED 25
TO 50 YARDS. CARS WERE TOSSED AND DESTROYED THROUGHOUT THE PATH OF
THE TORNADO…WITH ONE CAR WRAPPED AROUND A DEBARKED TREE IN PHIL
CAMPBELL. ALL ALONG THE PATH LENGTH…THOUSANDS OF HARDWOOD AND
SOFTWOOD TREES WERE SNAPPED. HUNDREDS OF TREES WERE ALSO DEBARKED AND
TWISTED…AND HAD ONLY STUBS OF LARGEST BRANCHES REMAINING. EF-5
DAMAGE CONTINUED SIMILARLY NORTHEAST FROM PHIL CAMPBELL…ROUGHLY
ALONG COUNTY ROADS 81 AND 82 TOWARD THE COMMUNITY OF OAK GROVE.

Ctsy Dave Nadler NWS who did some of the storm surveys that rated and documented the tornadoes.

IN OAK GROVE…THE TORNADO MAY HAVE REACHED A RELATIVE MAXIMUM IN
INTENSITY WELL INTO THE EF-5 CATEGORY AS THE DAMAGE WAS SLIGHTLY
MORE INTENSE AND THE PATH WIDTH WAS AT A MAXIMUM OF GREATER THAN ONE
MILE. A LARGE SWATH OF COMPLETE DEVASTATION WAS NOTED IN OAK GROVE
ALONG COUNTY ROADS 38 AND SMITH LANE. A LARGE WELL CONSTRUCTED HOME
WITH EXTENSIVE ANCHORING WAS RAZED WITH DEBRIS CARRIED WELL AWAY
FROM THE SITE. A CORVETTE WAS MANGLED AND THROWN A MEASURED 641
FEET. ANOTHER LARGE VEHICLE IS STILL MISSING. A BLOCK HOME NEXT DOOR
WAS ALSO DISINTEGRATED. ALONG SMITH LANE A BLOCK HOME WAS WIPED OUT
AND THE ONLY REMAINS OF A NEARBY CHICKEN HOUSE WAS A SMALL PIECE OF A
METAL TRUSS. IN THIS SAME AREA…THE TREE DAMAGE WAS COMPLETE AND A
LARGE PERCENTAGE OF TREES WERE STRIPPED BARE.

Summary of the North AL. tornadoes. From NWS.

THE TORNADO CONTINUED TO TRACK NORTHEAST INTO LAWRENCE COUNTY AS AN
EF-5 NEAR THE MT. HOPE AREA WHERE SIGNIFICANT DEVASTATION WAS
INCURRED TO SINGLE FAMILY HOMES AND A RESTAURANT. NOTHING BUT THE
FOUNDATION AND A PILE OF DEBRIS REMAINED IN THIS AREA…AND A SMALL
PORTION OF THE RESTAURANT FOUNDATION BUCKLED. THOUSANDS OF HARDWOOD
AND SOFTWOOD TREES WERE SNAPPED…WITH A SIGNIFICANT NUMBER OF TREES
TWISTED AND DEBARKED WITH ONLY STUBS OF BRANCHES REMAINING. MANY
MOBILE HOMES WERE ALSO DESTROYED WITH THE FRAMES MANGLED…AND A
SINGLE FAMILY HOME WAS COMPLETELY DESTROYED WITH THE WALLS AND
CONTENTS STREWN OVER A HUNDRED YARDS.

FURTHER NORTHEAST THE DAMAGE WAS SLIGHTLY LESS INTENSE (HIGH END
EF-3 TO LOW END EF-4)…WITH MORE TREES SNAPPED AND TWISTED AS THE
TORNADO REACHED HIGHWAY 24. AT THIS LOCATION 4 CHICKEN HOUSES WERE
DESTROYED WITH MUCH OF THE DEBRIS WRAPPED AROUND DEBARKED TREES. TVA
HIGH VOLTAGE POWER LINE TRUSSES WERE ALSO DESTROYED AT THIS LOCATION.

AS THE TORNADO CONTINUED NORTHEAST MORE SIGNIFICANT DAMAGE OCCURRED
IN AND AROUND THE LANGTOWN COMMUNITY NORTH OF MOULTON. ON THE WEST
SIDE OF ALABAMA HIGHWAY 33…SEVERAL HOMES SUSTAINED SIGNIFICANT
DAMAGE WITH ROOFS MISSING OR ONLY INTERIOR ROOMS REMAINING. A NEARBY
STORE AND GAS STATION ALSO SUSTAINED SIGNIFICANT DAMAGE.

THE TORNADO STRENGTHENED AGAIN TO A HIGH END EF-4 AS IT MOVED INTO
COUNTY ROADS 214 AND 298…WHERE MULTIPLE HOUSES AND MOBILE HOMES
WERE COMPLETELY DESTROYED. SEVERAL CARS WERE TOSSED INTO FIELDS AND
WRAPPED AROUND TREES ALONG COUNTY ROAD 291 AND 292. ONE VEHICLE WAS
TOSSED INTO A LARGE HARDWOOD TREE THAT WAS ALSO DEBARKED. TREE AND
MOBILE HOME DAMAGE CONTINUED ALONG COUNTY ROADS 217 AND 222…WHERE A
HANDFUL OF LARGE HIGH TENSION TVA POWER POLES WERE DESTROYED.

SUSTAINED EF-4 DAMAGE CONTINUED NORTHEAST TOWARDS ALABAMA HIGHWAY
20…WHERE A RESTAURANT WAS COMPLETELY DESTROYED AND TWO SINGLE
FAMILY HOUSES WERE SIGNIFICANTLY DAMAGED. TREE DAMAGE APPEARED TO
CONTINUE INTO EXTREME NORTHWESTERN MORGAN COUNTY.

LIMESTONE AND MADISON ALABAMA:

AN INITIAL AERIAL SURVEY WAS CONDUCTED ON THURSDAY MORNING FROM THE
TENNESSEE RIVER ALONG THE LAWRENCE/LIMESTONE COUNTY LINE NORTHEAST
THROUGH TANNER AND INTO MADISON COUNTY BEYOND THE ANDERSON HILLS
SUBDIVISION. SEVERAL AREAS OF INTENSE DAMAGE WERE NOTED ALONG A SOLID
TRACK WITH THE MOST INTENSE DAMAGE NOTED NEAR THE COMMUNITY OF TANNER
AND NEAR ANDERSON HILLS IN MADISON COUNTY. HOMES WERE COMPLETELY
OBLITERATED ALONG A WIDE SWATH IN BOTH OF THESE AREAS. NEARLY A DOZEN
HIGH TENSION POWER LINES WERE SNAPPED OR TAKEN TO THE GROUND IN
LIMESTONE COUNTY. CONCRETE POWER POLES WERE ALSO SNAPPED OFF AT THEIR
BASE.

A SUBSEQUENT GROUND TEAM…AIDED BY A STORM SURVEY EXPERT FROM THE
UNIVERSITY OF ALABAMA IN HUNTSVILLE…SURVEYED THE MOST INTENSE
DAMAGE IN LIMESTONE COUNTY. HIGH END EF-3 DAMAGE WAS NOTED OVER A
LARGE AREA IN EASTERN LIMESTONE COUNTY ALONG AND NORTH OF THE EAST
LIMESTONE HIGH SCHOOL. IN THE COMMUNITY OF TANNER…THE INTENSITY
WAS MAXIMIZED IN LIMESTONE COUNTY WITH A LARGE SWATH OF EF-4 DAMAGE
AND A NARROW CORRIDOR OF HIGH END EF-4 TO NEAR EF-5 DAMAGE. SEVERAL
WELL CONSTRUCTED HOMES WITH ANCHOR BOLTING WERE COMPLETELY WIPED
CLEAN. ONE HOME HAD THE DEBRIS LOFTED OVER 300 HUNDRED YARDS WITH
LARGE ITEMS CARRIED COMPLETELY AWAY. INTENSE GROUND SCARRING WAS
NOTED IN THIS AREA. IN ADDITION…A LARGE CARGO CONTAINER WAS PICKED
UP AND BLOWN APPROXIMATELY 600 YARDS AND SEVERAL CARS WERE CARRIED
AIRBORNE FOR HUNDREDS OF YARDS. IN ALL…HUNDREDS OF HOMES RECEIVED
MODERATE TO MAJOR DAMAGE ALONG THE PATH WITH MANY OF THESE BEING
TOTAL LOSSES.

THE TORNADO CROSSED INTO MADISON COUNTY EAST OF THE LIMESTONE COUNTY
PRISON…ALONG ORVIL SMITH ROAD WITH A PATH WIDTH OF 1/2 MILE. THE
TORNADO MAINTAINED AN EF-3 STRENGTH WITH WINDS OF 140 TO 160 MPH AND
A PATH WIDTH OF 1/4 TO 1/2 MILE FOR MUCH OF ITS TRACK EAST-NORTHEAST
ACROSS OLD RAILROAD BED ROAD AND FORD CHAPEL ROAD…BEFORE NARROWING
TO AROUND 300 YARDS IN ANDERSON HILLS. DOZENS OF WELL CONSTRUCTED
HOMES WERE DESTROYED…IN SOME CASES WITH ALL EXTERIOR WALLS
COLLAPSING IN BOTH SINGLE AND TWO STORY HOMES. AT LEAST 3-5 MOBILE
HOMES WERE EITHER DESTROYED OR SWEPT COMPLETELY. AT LEAST 2 OTHER
WELL CONSTRUCTED HOMES HAD COMPLETE WALL COLLAPSE IN ANDERSON HILLS
AND WERE SHIFTED OFF THEIR FOUNDATION. THIS DAMAGE WAS ONCE AGAIN
CONSISTENT WITH LOW END EF-4 WIND SPEEDS OF AROUND 170 MPH.
NUMEROUS TALL PINES AND OTHER HARDWOOD TREES WERE SNAPPED…UPROOTED
AND DEBARKED ALONG THE ENTIRE PATH. THE PATH WIDTH WIDENED ONCE
AGAIN TO UP TO 1/2 MILE AS THE TORNADO TRACKED THROUGH RESIDENTIAL
AREAS ALONG BALD EAGLE LANE…OLD ELI ROAD…AND GINNERY ROW. AT
LEAST TWO OF THESE HOMES HAD COMPLETE WALL COLLAPSE…BUT THESE
STRUCTURES HAD FOUNDATION STRAPS AND NAILS IN LIEU OF BOLTS. AT
LEAST ONE FATALITY WAS CONFIRMED AT ONE OF THESE RESIDENCES. THIS
DAMAGE WAS CONSISTENT WITH HIGH END EF-3 WIND SPEEDS OF 140 TO 160
MPH. THE TORNADO LIFTED JUST SOUTH OF PATTERSON LANE AFTER TWISTING
IRRIGATION EQUIPMENT AND SNAPPING ADDITIONAL TREES. AN EF0 TORNADO
WITH PEAK WIND SPEEDS OF 70 MPH REDEVELOPED ALONG GRIMWOOD ROAD AND
WALKER LANE SOUTH OF HAZEL GREEN…UPROOTING OR SNAPPING A FEW
TREES. THE TORNADO WEAKENED OR MAY HAVE LIFTED VERY BRIEFLY ACROSS
NORTHEAST MADISON COUNTY BEFORE STRENGTHENING AGAIN AS IT ENTERED
FRANKLIN COUNTY TENNESSEE.

DURING MUCH OF THE LIFECYCLE OF THIS TORNADO ACROSS NORTH ALABAMA…
THERE WAS EVIDENCE OF POSSIBLE SATELLITE VORTICES WHICH CAUSED
POINTS OF MORE SEVERE DAMAGE AS COMPARED TO ADJACENT RESIDENCES.
THERE WERE ALSO SEVERAL TREES KNOCKED DOWN JUST OUTSIDE THE PERIPHERY
OF THE TORNADIC CIRCULATION WHICH WERE LIKELY DUE TO MESOCYCLONE
WINDS WHICH WERE CONVERGENT TOWARD THE TORNADO.

FRANKLIN COUNTY TENNESSEE:

MORE STORM DAMAGE WAS SURVEYED BY NATIONAL WEATHER SERVICE PERSONAL
ON FRIDAY AND SATURDAY ACROSS SOUTHWEST FRANKLIN COUNTY TENNESSEE.
THE LONG TRACKED TORNADO THAT AFFECTED PARTS OF NORTHERN ALABAMA
CREATED MORE DAMAGE SOUTH OF HUNTLAND. ISOLATED AND MINOR EF-0 TREE
DAMAGE WAS NOTED AT THE INTERSECTION OF JOHN HUNTER HIGHWAY (STATE
ROUTE 122) AND LIMESTONE ROAD NEAR THE LINCOLN/FRANKLIN COUNTY LINE.

MORE SIGNIFICANT DAMAGE WAS NOTED…STARTING ABOUT 1.4 MILES SOUTH
SOUTHWEST OF HUNTLAND. A CINDER BLOCK BUILDING SUFFERED DAMAGE TO
ITS FLAT ADOBE ROOF…WITH SOME OF BLOCKS NEAR THE ROOF (AROUND 20
FEET OFF OF THE GROUND) PUSHED OUT…RESULTING IN EF-2 DAMAGE.
SURVEYORS COULD NOT DIRECTLY EXAMINE THE ROOF GIVEN THIS BUILDING
WAS ON THE HIGHEST GROUND IN THE VICINITY. NEARBY…A SINGLE FAMILY
HOME OF CINDER BLOCK CONSTRUCTION HAD ITS ROOF TOTALLY REMOVED…WITH
ANOTHER HOME ABOUT 1000 FEET AWAY HAVING SIGNIFICANT ROOF
DAMAGE…WITH OVER ONE HALF OF ITS ROOF REMOVED…AND SOME SHIFTING
OFF OF ITS FOUNDATION. DAMAGE WITH THE LATTER WAS CONSISTENT WITH
HIGH END EF-2 DAMAGE. A CHICKEN BUILDING NEARBY THE SECOND
HOME…WITH METAL GIRDING WAS COMPLETELY FLATTEN…CONSISTENT WITH
EF-2 DAMAGE.

A FARM COMPLEX SOUTH OF HICKORY GROVE ROAD HAD DAMAGE TO A NUMBER OF
STRUCTURES THERE. THE HOME AND THE MAIN CAR GARAGE HAD PART OF THEIR
ROOFS REMOVED. A BARN THAT WAS PROTECTING BALES OF HAY WAS
DESTROYED…WITH A FEW OF BALES BLOWN FROM 100-200 FEET FROM THEIR
ORIGINAL LOCATION. THE WORST DAMAGE WAS NOTED WITH LOWER END EF-3
DAMAGE TO A CINDER BLOCK UTILITY BUILDING ABOUT 200 FEET SOUTH OF
THE PRIMARY RESIDENCE. MOST OF ITS ROOF WAS REMOVED…WITH OVER HALF
OF ITS DOWNWIND WALL PUSHED OUTWARD. AN OLDER BARN NEARBY SUFFERED
LESSER EF-0 DAMAGE TO IT ROOF…WHILE THE TOP HALF OF A SILO NEAR
THAT BARN WAS MISSING. ANOTHER BARN STRUCTURE WAS COMPLETELY
DESTROYED NORTHWEST OF THE PRIMARY HOME. THE WIDTH AT THIS POINT WAS
APPROXIMATELY 1/4 MILE.

OTHER DAMAGE WAS NOTED NEAR THE INTERSECTION OF HICKORY GROVE ROAD
AND SUGAR COVE ROAD…WITH EF-1 DAMAGE TO SOME HEAVY FARM EQUIPMENT
AND EF-0 ROOF DAMAGE TO A NEARBY BARN. SCATTERED TREES WERE DOWNED
TO THE NORTHEAST…WITH 8 INCH FENCE POSTS 18 INCHES DEEP PULLED UP
NEAR HICKORY GROVE AND BUNCOMBE ROAD. THERE WAS EVIDENT THE TORNADO
CONTINUED TOWARD MOUNTAINS A FEW MILES FURTHER EAST…WITH SOME
TREES DAMAGED ALONG THE RIDGE.

SURVEYED BY: WFO HUNTSVILLE STAFF AND DR. KEVIN KNUPP/UAH