SUMMARY:

A SERIES OF THUNDERSTORMS DEVELOPED ACROSS THE REGION DURING THE MID AND LATE AFTERNOON HOURS ON SATURDAY SEPTEMBER 17 2005. A LARGE RIDGE OF HIGH PRESSURE WAS SITUATED ACROSS SOUTHEAST TEXAS. THE CLOCKWISE CIRCULATION AROUND THIS BROAD RIDGE ALLOWED A CHANNEL OF PACIFIC MOISTURE TO STREAM OVER THE AREA AND INTERACT WITH SULTRY TEMPERATURES WELL INTO THE 90S. IN FACT, THE HIGH TEMPERATURE ON SATURDAY AT THE LUBBOCK INTERNATIONAL AIRPORT REACHED 98 DEGREES WHICH TIED THE PREVIOUS RECORD SET IN 1997.

SEVERE THUNDERSTORMS DEVELOPED AND THE FIRST REPORTS OF SEVERE HAIL, PENNY SIZE AND LARGER, WERE RECEIVED AT 405 PM BY LAW ENFORCEMENT IN LAMB COUNTY. HAIL RANGING FROM PENNIES TO QUARTERS OCCURRED ACROSS LAMB, LYNN, AND HALE COUNTIES THROUGH 506 PM WITH REPORTS FROM TRAINED SPOTTERS, MEDIA STORM CHASERS, AND EMERGENCY RESPONDERS. AS THE AFTERNOON ROGRESSED, SEVERE HAIL CONTINUED TO OCCUR FROM THUNDERSTORMS. LARGE HAIL WAS REPORTED IN LUBBOCK COUNTY BETWEEN 512 PM AND 545 PM WITH SIZES RANGING FROM GOLFBALLS TO TENNIS BALLS TO A FEW BASEBALL SIZED HAIL STONES COVERING THE GROUND IN THE SLATON AREA.

AS THE SEVERE THUNDERSTORMS PROGRESSED TO THE EAST AND NORTHEAST, NICKEL SIZE HAIL WAS REPORTED NEAR FLOYDADA. THE TEXAS TECH WEST TEXAS MESONET STATION LOCATED 2 MILES NORTHEAST OF FLOYDADA MEASURED A SEVERE WIND GUST OF 68 MPH AT 615 PM.

BETWEEN 930 PM AND 130 AM, AN AREA OF DISSIPATING THUNDERSTORMS PROGRESSED ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST OVER TERRY, HOCKLEY, LUBBOCK, LYNN, GARZA AND CROSBY COUNTIES. AS THIS ACTIVITY PUSHED THROUGH THE REGION, STRONG WINDS AND ASSOCIATED HEAT BURSTS OCCURRED AT SEVERAL LOCATIONS. A HEAT BURST OCCURS WHEN AIR RAPIDLY DESCENDS FROM A DISSIPATING THUNDERSTORM, TYPICALLY WITH VERY LITTLE IF ANY RAINFALL. AS THE AIR SINKS, COMPRESSION WILL FORCE HEATING, DRYING, AND A RAPID RISE IN SURFACE TEMPERATURE. IN ADDITION TO A RISE IN TEMPERATURE, HEAT BURSTS CAN BE ACCOMPANIED BY STRONG AND GUSTY WIND.

THE HAIL AND STRONG WINDS SATURDAY NIGHT AND EARLY SUNDAY MORNING RESULTED IN VARIED AMOUNTS OF DAMAGE ACROSS THE AREA. LARGE TREES AND/OR TREE BRANCHES WERE DOWNED, STRUCTURAL DAMAGE TO CAR PORTS AND OVERHANG PROTECTION TO RESIDENT PORCHES, COTTON PLANTS DESTROYED, AUTOMOBILES, ROOFING AND RELATED STRUCTURES WERE DAMAGED. THE DAMAGE TO AUTOMOBILES AND OTHER WINDOWS OCCURRED AS NEARBY GRAVEL WAS LIFTED BY THE STRONG WIND AND PENETRATED WINDSHIELDS AND SIDE WINDOWS.

DAMAGE SURVEY:

Pictures of damage from a Heat Burst that affected Lubbock on September 17-18, 2005. Click on the images for a larger view. (Photographs taken by Brian LaMarre, Warning Coordination Meteorologist, WFO Lubbock, TX)

THE NATIONAL WEATHER SERVICE CONDUCTED A DAMAGE SURVEY AT THE MEMORIAL BAPTIST CHURCH IN LUBBOCK. THE CHURCH HAD A LARGE HAIL AND RAIN ROOF IN PLACE ABOVE A PERMANENT ROOF. THIS COVERING WAS MADE OF SHEET METAL AND HAD AN OVERLAP OF APPROXIMATELY SIX INCHES ON THE SOUTH FACING WALL. WHEN THE STRONG SOUTH WIND UP TO 70 MPH BREACHED THIS ROOF, THE METAL WAS PEALED OFF AND BECAME AIRBORNE AND LANDED ON TREES ON THE NORTH SIDE OF THE CHURCH, AS WELL AS A RESIDENCE ACROSS THE STREET.

Pictures of damage from a Heat Burst that affected Lubbock on September 17-18, 2005. Click on the images for a larger view. (Photographs taken by Brian LaMarre, Warning Coordination Meteorologist, WFO Lubbock, TX)

SEVERAL OF THE TEXAS TECH WEST TEXAS MESONET STATIONS MEASURED THE HEAT BURST AND HIGH WIND EVENTS. THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN LUBBOCK, LOCATED IN THE SCIENCE SPECTRUM
BUILDING, MEASURED A 15 DEGREE RISE IN TEMPERATURE WITH A 67 MPH WIND GUST AT 1155 PM. THE FOLLOWING ARE SOME OF THE MORE SIGNIFICANT MEASUREMENTS.

BROWNFIELD 2 SOUTH...8 DEGREE RISE...53 MPH GUST...925 PM.
LUBBOCK 3 WEST...13 DEGREE RISE...53 MPH GUST...1210 AM.
SLATON 2 NORTHEAST...15 DEGREE RISE...56 MPH GUST...1230 AM.
RALLS 1 SOUTHEAST...12 DEGREE RISE...57 MPH GUST...120 AM.

Graph of the temperature (F), dewpoint (F), wind speed (mph), wind gust (mph), and wind direction (degrees from north) in Lubbock for September 17-18, 2005. The graph and data is courtesy of the Texas Tech West Texas Mesonet.

THE ABOVE IMAGE DISPLAYS THE TEMPERATURE AND DEWPOINT TEMPERATURE GRAPHED IN THE UPPER HALF OF THE IMAGE, WITH THE WIND DIRECTION, WIND SPEED AND WIND SPEED GUST IN THE LOWER HALF. THE GRAPHS CLEARLY SHOW A LARGE INCREASE IN TEMPERATURE AND DECREASE IN DEWPOINT TEMPERATURE (INDICATIVE OF A DECREASE IN SURFACE MOISTURE) IN LUBBOCK ASSOCIATED WITH THE HEAT BURST BETWEEN 22 AND 00 (1200 AND 100 AM ON SEPTEMBER 18TH). ADDITIONALLY, DURING THAT SAME TIME PERIOD, WINDS GUSTED TO AROUND 50 MPH, THUS PRODUCING THE WARM AND WINDY CONDITIONS ASSOCIATED WITH A HEAT BURST.

IN COMPARISON TO THE SITES THAT EXPERIENCED LARGE TEMPERATURE RISES AND HIGH WIND SPEEDS, STATIONS MEASURING LESS RISE IN TEMPERATURE MEASURED LOWER WIND SPEED GUSTS.

LAMESA 2 SOUTHEAST...5 DEGREE RISE...27 MPH GUST...1135 PM.
GRAHAM 5 SOUTHWEST...4 DEGREE RISE...35 MPH GUST...1210 AM.

Pictures of damage from a Heat Burst that affected Lubbock on September 17-18, 2005. Click on the images for a larger view. (Photographs taken by Brian LaMarre, Warning Coordination Meteorologist, WFO Lubbock, TX)

HEAT BURSTS AND RELATED HIGH WIND EVENTS ARE NOT UNCOMMON FOR THIS AREA. IN ASSOCIATION WITH HEAT BURSTS, ON MAY 10 2005 BROWNFIELD MEASURED A 79 MPH WIND GUST. ON MAY 23RD, PAMPA AND MCLEAN
MEASURED A TEMPERATURE OF 91 AND 92 DEGREES AT 530 AM AND 605 AM, RESPECTIVELY. AND ON JUNE 6TH, ODONNELL MEASURED A 63 MPH WIND GUST AT 1205 AM, FOLLOWED BY A 78 MPH GUST AT 1255 AM IN JAYTON.

AS SEEN OVER THE WEEKEND, SEVERE WEATHER CAN OCCUR IN ANY MONTH OF THE YEAR, AND NOT JUST DURING THE STANDARD SEASON OF APRIL THROUGH JUNE. IT IS IMPORTANT TO BE AWARE OF THE LATEST WEATHER FORECAST AND PREPARE AHEAD OF TIME FOR SEVERE WEATHER CONDITIONS.

BRIAN LAMARRE
WARNING COORDINATION METEOROLOGIST
NATIONAL WEATHER SERVICE
LUBBOCK TEXAS

Note: The below information contains preliminary reports as they were received throughout the severe weather event.

PRELIMINARY LOCAL STORM REPORTS (CDT):

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE LUBBOCK TX
840 AM CDT SUN SEP 18 2005

TIME(CDT)   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0405 PM     HAIL             LITTLEFIELD             33.92N 102.33W
09/17/2005  0.75 INCH        LAMB               TX   LAW ENFORCEMENT

0435 PM     HAIL             2 E FIELDTON            34.04N 102.19W
09/17/2005  1.00 INCH        LAMB               TX   TRAINED SPOTTER

            SKYWARN SPOTTER REPORTED 1 INCH HAIL NEAR THE
            INTERSECTION OF 168 AND 37

0445 PM     HAIL             OLTON                   34.18N 102.14W
09/17/2005  0.88 INCH        LAMB               TX   FIRE DEPT/RESCUE

0506 PM     HAIL             1 N NEW HOME            33.34N 101.91W
09/17/2005  1.00 INCH        LYNN               TX   BROADCAST MEDIA

0512 PM     HAIL             3 S WOODROW             33.40N 101.84W
09/17/2005  1.25 INCH        LUBBOCK            TX   PUBLIC

0521 PM     HAIL             4 W SLATON              33.44N 101.71W
09/17/2005  2.00 INCH        LUBBOCK            TX   BROADCAST MEDIA

            GOLFBALL TO HEN EGG HAIL COVERING THE GROUND

0530 PM     HAIL             HALE CENTER             34.06N 101.84W
09/17/2005  1.00 INCH        HALE               TX   TRAINED SPOTTER

            SKYWARN SPOTTER

0540 PM     HAIL             4 W SLATON              33.44N 101.71W
09/17/2005  2.75 INCH        LUBBOCK            TX   STORM CHASER

            GOLFBALL...TENNIS BALL AND BASEBALL HAIL COVERING THE
            GROUND. HAIL LASTED 4 MINUTES.

0545 PM     HAIL             SLATON                  33.44N 101.64W
09/17/2005  1.75 INCH        LUBBOCK            TX   FIRE DEPT/RESCUE

            HAIL HAS BEEN FALLING FOR 5 MINUTES

0615 PM     TSTM WND GST     2 NE FLOYDADA           34.00N 101.31W
09/17/2005  68 MPH           FLOYD              TX   MESONET

            MEASURED BY TEXAS TECH WEST TEXAS MESONET

0616 PM     HAIL             4 S FLOYDADA            33.93N 101.34W
09/17/2005  0.88 INCH        FLOYD              TX   FIRE DEPT/RESCUE

0616 PM     HAIL             2 N FLOYDADA            34.01N 101.34W
09/17/2005  0.88 INCH        FLOYD              TX   FIRE DEPT/RESCUE

1200 AM     NON-TSTM WND GST 5 S LUBBOCK             33.50N 101.88W
09/18/2005  67 MPH           LUBBOCK            TX   OFFICIAL NWS OBS

            HIGH WINDS SUSTAINED NEAR 50 MPH STARTED AROUND 1152 PM
            AND LASTED ABOUT 15 MINUTES

1215 AM     NON-TSTM WND DMG 1 S LUBBOCK             33.56N 101.88W
09/18/2005                   LUBBOCK            TX   STORM CHASER

            LARGE TREE DOWN AT 19TH AND AVE V IN LUBBOCK