NWS Lubbock, TX, April 21, 2007 Tornado Event

PUBLIC INFORMATION STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE LUBBOCK TX
1046 AM CDT THU APR 26 2007

...NWS CONDUCTS DAMAGE SURVEY FOLLOWING TORNADO IMPACTS ON APRIL
21 2007...

ON SUNDAY APRIL 22 2007...THE NATIONAL WEATHER SERVICE IN LUBBOCK DISPATCHED
AN ASSESSMENT TEAM TO INVESTIGATE THE DAMAGE IN OLTON AND TULIA...AS
WELL AS THE SURROUNDING AREAS. THE TEAM WAS COMPRISED OF STEVE COBB...NWS
LUBBOCK SCIENCE AND OPERATIONS OFFICER...AND BRIAN LAMARRE...NWS LUBBOCK
WARNING AND COORDINATION METEOROLOGIST.

DISCLAIMER: THE FOLLOWING REPORT IS PRELIMINARY AND IDENTIFIES
THREE TORNADOES ASSOCIATED WITH THE MOST SIGNIFICANT DAMAGE. TIMES
ARE APPROXIMATED. IT IS POSSIBLE THAT ADDITIONAL TORNADOES COULD
BE ADDED AND INFORMATION UPDATED AS MORE INFORMATION IS RECEIVED
IN THE FOLLOWING DAYS.

TORNADO #1: LITTLEFIELD TORNADO
RATED EF-0 LITTLE TO NO DAMAGE OBSERVED.
PATH LENGTH:  2 MILES.
MAX WIDTH: 200 YARDS.
TORNADO BEGAN AT 6:20 P.M. AND ENDED AT 6:24 P.M.
WITH ZERO FATALITIES/ZERO INJURIES.

THE TORNADO ORIGINATED IN SOUTHWEST LAMB COUNTY ABOUT 5 MILES WEST OF
LITTLEFIELD AND MOVED NORTHEAST. THE TORNADO REMAINED IN OPEN COUNTRY
AND DISSIPATED BEFORE THE STORM CROSSED U.S. HIGHWAY 84. THERE WERE
NO REPORTS OF DAMAGE.

TORNADO #2: OLTON - EDMONSON TORNADO
RATED: EF-2 (MAX WINDS 111-120 MPH)
PATH LENGTH: 24 MILES
MAX WIDTH: 1230 YARDS (7/10 OF A MILE)
TORNADO BEGAN AT 6:57 P.M. AND ENDED AT 7:36 P.M. WITH ZERO FATALITIES/1
INJURY.

THE TORNADO ORIGINATED 5 MILES SOUTH-SOUTHWEST OF OLTON AND MOVED NORTHEAST
CROSSING NORTHWEST HALE COUNTY...SOUTHEAST CASTRO COUNTY AND FAR SOUTHWEST
SWISHER COUNTY BEFORE DISSIPATING ABOUT 10 MILES NORTHWEST OF EDMONSON.

THE FIRST VISIBLE DAMAGE INCLUDED FIVE MEDIUM VOLTAGE POWER POLES DOWNED
JUST EAST OF THE INTERSECTION OF FM168 AND CR162. JUST EAST OF THIS
LOCATION...THE TOPS OF FIVE POWER POLES WERE BLOWN OFF TO THE NORTH
AND TWO CENTER PIVOTS WERE OVERTURNED...ONE BLOWN EAST TO WEST AND
ANOTHER SOUTHWEST TO NORTHEAST. FARTHER TO THE NORTHEAST ALONG THE TORNADO
PATH...ALONG CR152 EAST OF FM168...TWO POWER POLES WERE SHEARED OFF
AND A MUTLI-STORY HOUSE SUFFERED ROOF DAMAGE WITH A SMALL PORTION OF
THE ROOF RIPPED OFF ON THE SOUTHEAST SIDE. SKIRTING WAS PULLED OFF A
MOBILE HOME ACROSS THE ROAD FROM THE HOUSE. OTHER MINOR DAMAGE WAS
OBSERVED TO OUT-BUILDINGS NEAR THE RESIDENCE.

THIS DAMAGE WAS CONSISTENT WITH WIND SPEEDS OF 85 TO 95 MPH.

EVIDENCE WAS OBSERVED THAT THE TORNADO REMAINED ON THE GROUND UNTIL
CROSSING U.S. HIGHWAY 70 EAST OF OLTON...INCLUDING SEVERAL CENTER
PIVOT IRRIGATION SYSTEMS OVERTURNED WITH MULTIPLE POWER POLES SNAPPED
OR SHEARED OFF WITHIN 3 TO 5 FEET OF THE GROUND. THIS DAMAGE WAS OBSERVED
APPROXIMATELY 1.5 MILES EAST OF FM168 ALONG CR321. THE WIDEST PATH OF
THE TORNADO WAS ALSO OBSERVED TO BE 7/10 OF A MILE ALONG CR321.

THE DAMAGE WAS CONSISTENT WITH WIND SPEEDS OF 95 TO 105 MPH.

THE TORNADO CROSSED U.S. HIGHWAY 70 BEGINNING ABOUT 2 MILES EAST
OF OLTON. THREE HOMES WERE DAMAGED ALONG THE HIGHWAY SUFFERING MOSTLY
ROOF DAMAGE. THE THIRD HOME SUSTAINED THE MOST DAMAGE TO THE ROOF WITH
A LARGE EVERGREEN TREE LYING WEST TO EAST ONTO THE HOME. TIN WAS ALSO
PEELED OFF A SHED AND BLOWN TO THE NORTH. ABOUT 1/10 OF A MILE EAST
OF THESE RESIDENCES...A FOURTH AND FINAL HOME WAS SEVERELY
DAMAGED. THE ROOF OF THIS RESIDENCE WAS COMPLETELY TORN OFF...A
LARGE METAL STRUCTURE HOUSING FARM EQUIPMENT AND VEHICLES WAS DESTROYED
WITH METAL BEAMS TWISTED. DEBRIS WAS SCATTERED ABOUT 1/4 MILE NORTH
INTO A FIELD. ONE INJURY WAS SUSTAINED IN THE HOME DURING THE TORNADO...AS
A RESIDENT TOOK SHELTER UNDER A KITCHEN TABLE. THE TORNADO PATH LENGTH
ALONG U.S. HIGHWAY 70 WAS ESTIMATED TO BE 4/10 OF A MILE ENDING NEAR
THE HALE COUNTY LINE.

THE DAMAGE WAS CONSISTENT WITH WIND SPEEDS OF 110 TO 120 MPH.

THE TORNADO CONTINUED NORTHEAST ACROSS MOSTLY RURAL FARM LAND. A STORAGE
BARN SUSTAINED MINOR DAMAGE TO THE ROOF AND THREE CENTER PIVOTS WERE
OVERTURNED ABOUT ONE MILE NORTH OF U.S. HIGHWAY 70 ALONG CR80. ALSO
ALONG THIS ROAD...SEVERAL POWER POLES WERE SHEARED OFF AT THE GROUND
FOR APPROXIMATELY 4/10 OF A MILE.

THE DAMAGE WAS CONSISTENT WITH WIND SPEEDS OF 90 TO 100 MPH.

THE TORNADO CONTINUED ON A TRACK TO THE NORTHEAST HOWEVER LITTLE TO
NO DAMAGE WAS OBSERVED BY THE SURVEY TEAM.

TORNADO #3: TULIA TORNADO
RATED: EF-2 (MAX WINDS 125-135 MPH)
PATH LENGTH: 3.5 MILES
MAX WIDTH: 200 YARDS
TORNADO BEGAN AT 7:57 P.M. AND ENDED AT 8:01 P.M. WITH ZERO FATALITIES/3
INJURIES.

THE TORNADO ORIGINATED NEAR THE POWER PLANT AT THE INTERSECTION OF
BROADWAY AND U.S. 87 AND CONTINUED NORTH ACROSS THE WEST SIDE OF TULIA
BEFORE DISSIPATING JUST NORTHEAST OF THE TULIA/SWISHER COUNTY MUNICIPAL
AIRPORT.

SIGNIFICANT DAMAGE WAS OBSERVED ALONG U.S. 87 WITH NUMEROUS IMPACTS
TO BUSINESSES. THE MOST SIGNIFICANT DAMAGE OCCURRED AT A LOCAL SUPERMARKET
AT THE INTERSECTION OF U.S. 87 AND 6TH STREET. A LARGE PORTION OF THE
ROOF WAS REMOVED ON THE EAST SIDE OF THE STRUCTURE...WITH ONE EXTERIOR
WALL COLLAPSED INWARD. A PORTION OF THE ROOF CORNER ON THE SOUTHWEST
SIDE OF THE BUILDING HAD COLLAPSED. IN ADDITION...A PORTION OF THE
NORTHWEST EXTERIOR WALL HAD COLLAPSED.

THIS DAMAGE WAS CONSISTENT WITH WIND SPEEDS OF 125 TO 135 MPH.

THE LOCAL AUTO DEALERSHIP...LOCATED TO THE SOUTH OF THE
SUPERMARKET...SUSTAINED A LARGE AMOUNT OF DAMAGE. FORTY-ONE
VEHICLES RECEIVED DAMAGE MAINLY FROM FLYING DEBRIS. A MOTOR HOME
ON THE PROPERTY WAS OVERTURNED FROM SOUTHEAST TO NORTHWEST. A
LARGE OVERHEAD DOOR ON THE EAST SIDE FAILED RESULTING IN
ADDITIONAL FAILURE TO THE WEST WALL. A LARGE STORAGE CONTAINER WAS
BLOWN INTO THE SOUTHWEST CORNER OF THE BUILDING COLLAPSING A
PORTION OF THE ROOF.

THE DAMAGE WAS CONSISTENT WITH WIND SPEEDS OF 95 TO 105 MPH.

A LARGE METAL BUILDING ON THE EAST SIDE OF U.S. 87 ABOUT ONE BLOCK
SOUTH OF THE DEALERSHIP ALSO SUSTAINED MAJOR DAMAGE WITH THE FAILURE
OF FOUR LARGE OVERHEAD DOORS AND BUCKLING OF ROOF PURLINS ON THE
SOUTH SIDE OF THE BUILDING.

THE DAMAGE WAS CONSISTENT WITH WIND SPEEDS OF 110 TO 120 MPH.

MODERATE DAMAGE WAS OBSERVED TO THE NORTH AND NORTHEAST OF THE
SUPERMARKET ENTERING A RESIDENTIAL PORTION OF TOWN. DAMAGE OCCURRED
TO A MOBILE HOME COMMUNITY BETWEEN 8TH AND 9TH STREETS JUST WEST OF
HIGHLAND ELEMENTARY SCHOOL. A TOTAL OF FIVE MOBILE HOMES WERE
IMPACTED...TWO OF WHICH WERE COMPLETELY DESTROYED. THE WALLS AND
ROOFS SEPARATED WITH THE UNDERCARRIAGE SEPARATED AND TWISTED. DEBRIS
WAS BLOWN TO THE WEST NORTHWEST TOWARD THE CENTER OF THE TORNADO
CIRCULATION.

THE DAMAGE WAS CONSISTENT WITH WIND SPEEDS OF 85 TO 95 MPH FOR THE DAMAGED
MOBILE HOMES...AND 105 TO 125 MPH FOR THE DESTROYED MOBILE HOMES.

THE MOST SIGNIFICANT RESIDENTIAL DAMAGE OCCURRED IN A SUBDIVISION
ALONG NORTHWEST 9TH THROUGH NORTHWEST 11TH STREETS. ACROSS THIS AREA
ALONG NORTHWEST 9TH STREET...THE NORTHERLY CIRCULATION AROUND THE
TORNADO PENETRATED THE GARAGE DOORS ON SEVERAL HOMES FORCING THE
OBSERVED ROOF DAMAGE. THE DEBRIS FROM THESE HOMES WAS SCATTERED TO
THE SOUTH IN AN ADJACENT FIELD.

THE TORNADO DAMAGE NORTH OF THIS AREA...ALONG NORTHWEST 10TH STREET...WAS
SPORADIC AS THE CIRCULATION PATTERNS WITHIN THE TORNADO FLUCTUATED.
THE DAMAGE BECAME MORE SIGNIFICANT AND PRONOUNCED ALONG NORTHWEST
11TH STREET JUST WEST OF AIRPORT ROAD. SEVERAL HOMES WERE HEAVILY
DAMAGED ALONG 11TH STREET...WITH SIGNIFICANT OR COMPLETE REMOVAL OF ROOF
MATERIAL AND FAILURE TO SOME EXTERIOR WALLS NOTED WITH THE FIRST
THREE RESIDENCES. DEBRIS FROM THESE HOMES WAS SCATTERED TO THE NORTH
AND NORTHWEST IN AN ADJACENT FIELD.

THE DAMAGE WAS CONSISTENT WITH WIND SPEEDS RANGING FROM 100 TO 110
MPH TO THE MODERATELY DAMAGED HOMES...AND RANGING FROM 125 TO 135
MPH ON THE SIGNIFICANTLY DAMAGED HOMES CLOSER TO AIRPORT ROAD.

AS THE TORNADO PROGRESSED TO THE NORTH AND NORTHEAST FROM THIS AREA...REPORTS
INDICATED THE TORNADO BECAME LARGER. WEAK TO MODERATE DAMAGE WAS NOTED
TO FARM HOUSES ON CR13...AS WELL AS CENTER PIVOTS AND STORAGE STRUCTURES
TO THE EAST AND NORTHEAST OF THE TULIA/SWISHER COUNTY MUNICIPAL AIRPORT.

THE DAMAGE WAS CONSISTENT WITH WIND SPEEDS OF 95 TO 105 MPH.

THE NATIONAL WEATHER SERVICE IN LUBBOCK WOULD LIKE TO THANK ALL OF
THOSE INVOLVED IN PROVIDING DETAILED INFORMATION TO THE NWS SURVEY
TEAM.  THE ASSESSMENT WOULD NOT HAVE BEEN COMPLETE WITHOUT THE
EFFORTS OF LOCAL EMERGENCY RESPONSE OFFICIALS...MEDIA...AND THE
RESIDENTS OF OLTON AND TULIA.

IN ADDITION...THE NWS DAMAGE SURVEY BENEFITED FROM COLLABORATION
WITH A TEXAS TECH UNIVERSITY CIVIL ENGINEERING PROFESSOR.  THE
PROFESSOR IS A LEADING EXPERT WHO SERVED AS A DEVELOPER OF THE
ENHANCED FUJITA SCALE FOR RATING TORNADO DAMAGE.

$$

CORRECTIONS MADE INCLUDE MODIFYING THE ESTIMATED WIND SPEEDS
ASSOCIATED WITH THE FIRST TWO TORNADOES SOUTH OF OLTON IN ORDER TO
BETTER MATCH THE DAMAGE OBSERVED. ALSO MINOR CORRECTIONS WERE MADE
TO THE DESCRIPTIONS OF THE DAMAGE PATH THROUGH TULIA FOR CLARITY.

COBB/LAMARRE