NWS Lubbock, TX, March 10, 2007 Severe Thunderstorms

...NWS CONDUCTS DAMAGE SURVEY FOLLOWING MARCH 10 2007 SEVERE
WEATHER IMPACTS AT ESTELLINE TEXAS IN HALL COUNTY...

ON SATURDAY MARCH 10 2007...SEVERE THUNDERSTORMS TRACKED ACROSS PARTS OF THE SOUTHERN PANHANDLE. BETWEEN 800 AND 830 PM A STORM MOVED THROUGH EASTERN HALL COUNTY CAUSING SIGNIFICANT WIND DAMAGE IN THE CITY OF ESTELLINE. A NUMBER OF STRUCTURES WERE DAMAGED OR DESTROYED...INCLUDING ONE TRAILER HOME WHERE 4 PEOPLE WERE INJURED.

ON THURSDAY MARCH 15 2007...THE NATIONAL WEATHER SERVICE IN LUBBOCK DISPATCHED AN ASSESSMENT TEAM TO INVESTIGATE THE DAMAGE. THE FOLLOWING REPORT IS A SUMMARY OF THE THEIR FINDINGS.

THE ASSESSMENT TEAM...COMPRISED OF JUSTIN WEAVER...NWS LUBBOCK METEOROLOGIST IN CHARGE...AND JOHN LIPE...NWS SENIOR HYDROLOGIST/METEOROLOGIST INVESTIGATED DAMAGE AROUND THE CITY OF ESTELLINE.

MAXIMUM WIND SPEEDS BASED ON THE DAMAGE WERE ESTIMATED BETWEEN 90 AND 100 MPH. THE DAMAGE SURVEYED IN THE AREA...COMBINED WITH NUMEROUS INTERVIEWS OF LOCAL RESIDENTS AND CITY AND COUNTY OFFICIALS...LED THE NATIONAL WEATHER SERVICE IN LUBBOCK TO CONCLUDE ON TWO MAIN IMPACTS FROM THE SEVERE THUNDERSTORM.

THE FIRST AND PREVAILING IMPACT OCCURRED FROM A SEVERE THUNDERSTORM DOWNBURST. THE DOWNBURST OCCURRED OVER THE CITY OF ESTELLINE AS A CORE OF HEAVY RAIN HIGHER IN THE ATMOSPHERE INTERACTED WITH DRY AIR BENEATH THE THUNDERSTORM TO DELIVER AN INTENSE DOWNRUSH OF AIR TOWARD THE GROUND.

Above are images of damage taken from the Estelline area. Click on the image for a larger view. (All photographs were taken by the NWS Lubbock Damage Survey Team.)

THE SECOND IMPACT PRODUCED SEVERE DAMAGE FROM A BRIEF TORNADO...AS NOTED IN SURVEY POINTS 9 AND 10 BELOW. THE TORNADO PRODUCING THIS DAMAGE...UNDER THE ATMOSPHERIC CONDITIONS PRESENT ON MARCH 10 2007...IS KNOWN AS A TYPE-B TORNADO FROM THE FUJITA CASE STUDIES. THE TYPE-B TORNADO FORMS MUCH LIKE A LANDSPOUT AS ROTATION NEAR THE GROUND IS LOFTED TOWARD THE BASE OF THE CLOUD WITHIN THE STORM UPDRAFT OR RISING AIR. THIS IS CONTRARY TO TORNADO FORMATION FROM A MESOCYCLONE THAT TYPICALLY DESCENDS FROM THE BASE OF A SEVERE THUNDERSTORM. THE DAMAGE WAS RATED EF-1 ON THE ENHANCED FUJITA SCALE OF TORNADO DAMAGE WITH ESTIMATED WINDS IN ESTELLINE BETWEEN 90 TO 100 MPH. DAMAGE SURVEYED SUGGESTED THE LANDSPOUT TORNADO IMPACTED THE AREA FOR ONE-QUARTER OF A MILE ALONG A SOUTHWEST TO NORTHEAST PATH ALONG AND TO THE WEST AND NORTH OF HIGHWAY 86 AND 287.

THE TOTAL OBSERVED DAMAGE AREA EXTENDED FROM ABOUT 1 MILE WEST OF ESTELLINE INTO TOWN. THE WORST DAMAGE WAS IN THE NORTHWEST QUADRANT OF THE SMALL COMMUNITY...HOWEVER ONE MOBILE HOME WAS DESTROYED ABOUT 2 BLOCKS EAST OF THE TOWN CENTER.

Above are images of damage taken from the Estelline area. Click on the image for a larger view. (All photographs were taken by the NWS Lubbock Damage Survey Team.)

1. THE FIRST INDICATION OF DAMAGE WAS LOCATED ONE MILE WEST OF TOWN TO THE NORTH OF STATE HIGHWAY 86 WHERE A CENTER PIVOT IRRIGATION SYSTEM WAS OVERTURNED.
2. AN 18-WHEELER TRAILER WAS OVERTURNED ON THE SOUTH SIDE OF HIGHWAY 86 CONSISTENT WITH VERY STRONG WEST WINDS.
3. ALSO ON THE WESTERN EDGE OF TOWN...JUST NORTH OF HIGHWAY 86...A MOBILE HOME WAS ROLLED ON TOP OF TWO VEHICLES AND CAME TO A STOP WHEN IT HIT A LARGE TREE. FOUR PEOPLE INSIDE THE HOME WERE INJURED DURING THE IMPACT. THE MOBILE HOME DID NOT APPEAR TO HAVE BEEN TIED DOWN AND ROLLED TO THE EAST CONSISTENT WITH WEST TO WEST- SOUTHWEST WINDS.
4. IMMEDIATELY EAST OF THE MOBILE HOME THE ROOF OF A 15X25 FOOT METAL SHED WAS RIPPED OFF.
5. JUST SOUTHEAST OF THE MOBILE HOME...A SMALL TRAVEL TRAILER WAS OBSERVED ROLLED TO THE EAST AND WAS LEANING UP AGAINST A SMALL HOME...WHERE IT WAS PREVIOUSLY PARKED BESIDE.
6. ON THE NORTHWESTERN EDGE OF THE TOWN SQUARE...TWO LARGE BRICK BUILDINGS WERE DESTROYED. THE ONE AT THE NORTH END APPEARED TO HAVE COMPLETELY COLLAPSED. THE SOUTHERN OF THE TWO HAD A MORE RECENTLY BUILT PEAKED METAL ROOF WHICH LIFTED THEN FELL BACK ON THE BUILDING. AS A RESULT...SOME OF THE WALLS HAD COLLAPSED...ESPECIALLY ON THE WEST AND EAST END.
7. ABOUT 100 YARDS NORTHWEST OF THE COLLAPSED BUILDINGS WAS A ROW OF 8 TRAILERS FOR 18-WHEELER RIGS. THE TWO TRAILERS SITUATED ON THE WESTERN END WERE PUSHED TO THE EAST AND UP AGAINST AN ADJACENT TRAILER. SIMILARLY...THE TRAILER ON THE EASTERN END WAS ROLLED ON ITS SIDE AND SLID ABOUT 60 FEET TO THE NORTHEAST INTO A TELEPHONE POLE AND SMALL TREE. A SECOND TRAILER FROM THE EASTERN END WAS PUSHED BACK AND TURNED SLIGHTLY.
8. ABOUT 100 YARDS WEST-NORTHWEST OF THE COLLAPSED BUILDING...
TWO COTTON TRAILERS WERE ROLLED NORTH-NORTHEAST AND WERE ON TOP OF EACH OTHER.
9. ABOUT 3 BLOCKS EAST-SOUTHEAST OF THE COLLAPSED BUILDING...AT THE INTERSECTION TWO BLOCKS EAST OF HARPER AND MCPHERSON STREETS...A MOBILE HOME WAS DESTROYED WITH DEBRIS SCATTERED TO THE WEST. THE METAL BASE OF THE MOBILE HOME REMAINED CLOSE TO ITS ORIGINAL POSITION...BUT ALL THE WALLS...ROOF AND REMAINING SECTIONS WERE FLATTENED AND SCATTERED TO THE WEST. ADDITIONAL SURVEY FINDINGS OF DEAD TREE LIMBS AND OTHER DEBRIS INDICATED THE STRONGEST WINDS AT THIS LOCATION WERE FROM THE EAST...SUGGESTING A CONVERGENT FLOW PATTERN AS WELL AS AN INDICATION OF TORNADIC ROTATION IN THE AREA.
10. TWO BLOCKS NORTHEAST OF THE TOWN SQUARE...LOCATED ON THE EAST SIDE OF U.S. HIGHWAY 287 AND JUST SOUTH OF MAYSEY STREET...A TRAVEL TRAILER AND OUTBOARD BOAT HAD BEEN ROLLED TO THE NORTH- NORTHEAST. THE TRAVEL TRAILER WAS UPSIDE DOWN ABOUT 100 FEET FROM ITS ORIGINAL POSITION AND THE WALLS HAD COMPLETELY DISINTEGRATED. THE BOAT WAS A HEAVY FIBERGLASS OUTBOARD AND HAD MOVED ABOUT 50 FEET...SEPARATED FROM ITS TRAILER.
11. TWO BLOCKS EAST OF THE TRAVEL TRAILER...AT THE NORTHEAST EDGE OF TOWN...A BARN HAD PARTS OF ITS SHEET METAL ROOF PEALED UP.
12. A HOME ONE BLOCK SOUTH OF TOWN CENTER HAD SHEET METAL ROOFS FROM PORCHES AND A SHED TORN OFF.
13. MISCELLANEOUS TREE AND MINOR ROOF DAMAGE WAS NOTED IN OTHER PARTS OF TOWN...BUT IT APPEARED TO HAVE BEEN MOST WIDESPREAD ON THE WEST SIDE OF U.S. 287.

Above are images of damage taken from the Estelline area. Click on the image for a larger view. (All photographs were taken by the NWS Lubbock Damage Survey Team.)

ON THE WESTERN SIDE OF TOWN THE STRONGEST WINDS APPEARED TO HAVE COME FROM THE WEST. NEAR THE TOWN SQUARE...THE MOST DAMAGING WINDS WERE ESTIMATED OUT OF THE SOUTHWEST. HOWEVER...A GENTLEMAN WHO RODE OUT THE STORM IN A BUILDING IMMEDIATELY SOUTH OF THE COLLAPSED BRICK BUILDINGS...NOTED IN ITEM 6...INDICATED THAT VERY STRONG EAST WINDS IMPACTED THE EAST-FACING DOOR OF THE BUILDING SECONDS BEFORE POWER WAS KNOCKED OUT AHEAD OF THE SEVERE THUNDERSTORM. THE OBSERVER INDICATED TWO MEN WERE TRYING TO HOLD THIS DOOR SHUT. TWO BLOCKS EAST OF TOWN...EAST WINDS DESTROYED A MOBILE HOME. AT THE NORTHERN EDGE OF TOWN THE STRONGEST WINDS WERE SURVEYED TO HAVE COME FROM THE SOUTH-SOUTHWEST.

THE NATIONAL WEATHER SERVICE IN LUBBOCK WOULD LIKE TO THANK THE LOCAL RESIDENTS IN ESTELLINE...LOCAL AND COUNTY OFFICIALS IN ESTELLINE AND HALL COUNTY...AND AMARILLO MEDIA AND EMERGENCY RESPONSE OFFICIALS FOR ALL OF THE HELP PROVIDED BEFORE AND DURING THE NATIONAL WEATHER SERVICE DAMAGE SURVEY.