Wildfire and Hail in Texas, May 12, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
328 PM CDT TUE MAY 12 2009

.SHORT TERM...
SHORT-TERM FOCUS IS ON CONVECTIVE DEVELOPMENT IN THE NEXT SEVERAL
HOURS. WELL-DEFINED SHTWV IS APPROACHING THE AREA FROM THE SW...AND
HAS SPARKED SOME VERY HIGH-BASED CONVECTION ACROSS SE NM. NEAR
GROUND LEVEL...LOW STRATUS HAS ALMOST COMPLETELY ERODED OUT OF THE
FA...BUT IT...ALONG WITH A LIFTING WARM FRONT...HAS HELPED PRODUCE A
SUBSTANTIAL TEMP GRADIENT ACROSS THE AREA. 19Z LAPS SHOWS A
WELL-DEFINED THETA-E MAX ROUGHLY ALONG I-27 AND THEN EAST ALONG 82.
FINALLY...THE DRYLINE IS TAKING SHAPE ACROSS THE SW COUNTIES...AND
PUSHING INTO THE CENTRAL COUNTIES...ALTHOUGH LATEST WEST TEXAS
MESONET OBS SHOW THAT WINDS ARE BACKING IN RESPONSE TO DEEPENING SFC
TROUGH FROM WESTERN KS INTO EAST-CENTRAL NM. THUS WE EXPECT THE
DRYLINE TO BECOME QUASI-STATIONARY NEXT FEW HOURS...ROUGHLY ALONG A
DIMMITT TO TAHOKA LINE. WITH WEAK LARGE-SCALE ASCENT SPREADING OVER
THE AREA...WEAK CONVERGENCE ALONG THE DRYLINE/WARM FRONT SHOULD BE
SUFFICIENT TO BREAK THROUGH THE CAP...ALTHOUGH CAP MAY STILL HOLD
UNTIL 6 PM OR SO...AND MAY LIMIT COVERAGE OF STORMS. ANY STORMS
THAT DEVELOP SHOULD BE CAPABLE OF PRODUCING LARGE HAIL/SVR WINDS
GIVEN MLCAPES NEAR 2K AND SUFFICIENT /AROUND 25-30 KTS/ DEEP-LAYER
SHEAR. ACROSS ROUGHLY THE NE QUAD OF THE FA...RICHER BL
MOISTURE/LOWER LCLS/ AND POSSIBLE FOCUS WITH FRONT/TERRAIN SHOULD
RESULT IN A ISOLD TORNADO THREAT...BUT SFC WIND SPEEDS WILL BE
MARGINAL AND STORMS MAY ALSO LOSE ROOTING IN SFC LAYER IF CAP IS TOO
STRONG. ONLY CHANGE TO POP GRIDS LATE THIS AFTN/EVE WAS TO ADD ISOLD
MENTION ACROSS THE WEST FOR THE POTENTIAL FOR HIGH-BASED NON-SVR
ACTIVITY TO THE WEST OF THE DRYLINE. OTHERWISE...ANY TSTM ACTIVITY
SHOULD MOVE INTO THE ROLLING PLAINS LATER THIS EVENING AND DIMINISH
BEFORE MIDNIGHT. DO NOT EXPECT A RETURN OF WIDESPREAD LOW
STRATUS/FOG OVERNIGHT AS LOW-LVL JET WILL VEER TO THE SW SHUNTING
DEEPER MOISTURE TO THE EAST. ON WEDNESDAY...DRYLINE IS FCST TO
QUICKLY MIX OUT INTO THE ROLLING PLAINS DUE TO VEERED FLOW IN
PRE-FRONTAL TROUGH. HAVE HELD ONTO SLGT CHC POPS ACROSS THE FAR
EASTERN ZONES WHERE SUFFICIENT MOISTURE MAY HOLD ON. OTHERWISE IT
SHOULD BE VERY WARM WITH HIGH TEMPS IN THE MID TO UPPER 90S.

&&

.LONG TERM...
MEDIUM RANGE MODELS ARE IN GOOD HARMONY WITH THE SYNOPTIC FLOW
THROUGH THIS WEEKEND BEFORE COMPLEXITIES EMERGE REGARDING THE
DE-AMPLIFICATION OF L/W RIDGING ALONG THE WEST COAST. PREDOMINANT
FLOW WILL TRANSITION FROM A MOSTLY ZONAL PATTERN WITH A FEW EMBEDDED
LOW-AMPLITUDE TROFS /PASSING WELL NORTH OF THE REGION/ INTO A +PNA
PATTERN BY FRIDAY. FIRST S/W TROF WED NIGHT IS STILL EXPECTED TO
DRIVE A COLD FRONT SOUTH INTO THE AREA OVERNIGHT RESULTING IN
POST-FRONTAL CLOUDS AND A TEMPORARY BREAK FROM THE 90 DEGREE HEAT.
SAID FRONT THEN STALLS TO OUR SOUTH BEFORE RETREATING THURS NIGHT IN
RESPONSE TO A STRONG LLJ. ALL INDICATIONS ARE THAT SUFFICIENT L/L
MOISTURE SHOULD RETURN FRIDAY FOR A POTENTIALLY ACTIVE DRYLINE
SETUP...ALTHOUGH LOW BULK SHEAR VALUES AT THIS TIME LOOK TO KEEP
CONVECTIVE MODES LOOSELY ORGANIZED. SURPRISINGLY...12Z
GFS/WRF-NMM/ECMWF ALL AGREE IN DEVELOPING CONVECTION FRI
AFTN/EVNG...SO INHERITED POPS WERE TRENDED UP SLIGHTLY. OTHERWISE
ONE LAST COLD FROPA EXPECTED EARLY SATURDAY BEFORE HEIGHTS ALOFT
REBUILD AHEAD OF A CLOSED HIGH PROGGED TO UNFOLD NEAR THE GREAT
BASIN. BEYOND THIS THE ECMWF REMAINS THE MOST PERSISTENT WITH
RIDGING ALONG THE WEST COAST WHEREAS THE GFS ADVERTISES A VIGOROUS
WAVE DROPPING INTO THE NRN ROCKIES. TOO MUCH UNCERTAINTY EXISTS AT
THIS TIME TO FAVOR ONE SOLUTION OVER THE OTHER AND ANY FORECAST
IMPLICATIONS CLOSE TO HOME BY MONDAY ARE QUITE MINIMAL...SO WON/T
FRET TOO MUCH ABOUT THE DETAILS AT THIS TIME.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        55  90  51  78  57 /  10  10  20  20  10
TULIA         63  91  52  77  57 /  20  10  20  20  10
PLAINVIEW     62  92  53  77  58 /  20  10  20  20  10
LEVELLAND     63  94  56  81  58 /  10  10  10  10  10
LUBBOCK       65  94  57  79  60 /  20  10  10  10  10
DENVER CITY   61  95  59  84  59 /  10  10  10  10  10
BROWNFIELD    64  95  59  83  59 /  10  10  10  10  10
CHILDRESS     65  95  58  75  62 /  30  10  20  20  10
SPUR          66  94  60  78  60 /  40  10  10  20  20
ASPERMONT     68  97  63  82  64 /  40  10  20  20  20

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

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HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LUBBOCK TX
219 PM CDT TUE MAY 12 2009

TXZ021>044-131930-
PARMER-CASTRO-SWISHER-BRISCOE-HALL-CHILDRESS-BAILEY-LAMB-HALE-
FLOYD-MOTLEY-COTTLE-COCHRAN-HOCKLEY-LUBBOCK-CROSBY-DICKENS-KING-
YOAKUM-TERRY-LYNN-GARZA-KENT-STONEWALL-
219 PM CDT TUE MAY 12 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE EXTREME SOUTHERN TEXAS
PANHANDLE...SOUTH PLAINS AND ROLLING PLAINS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

CONVECTIVE
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP NEAR A DRYLINE OVER
THE WESTERN TO CENTRAL SOUTH PLAINS LATE THIS AFTERNOON AND WILL
MOVE EASTWARD OVER THE ROLLING PLAINS THROUGH THE EVENING HOURS.
MODERATE TO STRONG INSTABILITY WILL COMBINE WITH SUFFICIENT WIND
SHEAR TO PRODUCE A FAVORABLE ENVIRONMENT FOR SUPERCELL STORMS.
THUS A THREAT FOR VERY LARGE HAIL AND DAMAGING WINDS WILL
ACCOMPANY THUNDERSTORMS LATER TODAY. A THREAT FOR ISOLATED
TORNADOES ALSO WILL EXIST...ESPECIALLY NEAR THE INTERSECTION OF A
WARM FRONT AND THE DRYLINE OVER THE NORTHERN SOUTH PLAINS AND
EXTREME SOUTHEASTERN PANHANDLE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY
SEVERE THUNDERSTORMS MAY BE POSSIBLE ON FRIDAY ALONG AND EAST OF
THE DRYLINE.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED LATER THIS AFTERNOON AND EVENING.