Severe Thunderstorm Warning 47, NWS Lubbock, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LUBBOCK TX
255 PM CDT WED MAY 2 2001

THE 12Z UA ANALYSIS SHOWED AN UPPER LEVEL TROF OVER THE WEST-CENTRAL
CONUS WITH A BROAD UPPER LEVEL RIDGE OVER THE EASTERN CONUS. THE 18Z
SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING FROM SOUTH OF CVS
NORTHEAST TO GAG. A DRYLINE EXTENDED WEST OF MAF NORTH TO EAST OF
LBB TO THE COLD FRONT NORTH OF SILVERTON.

A COMPLICATED FORECAST THROUGH DAY 3. THE ETA MODEL SHOWS THE SFC
FRONT CURRENTLY OVER THE NORTHWESTERN COUNTIES REMAINING STATIONARY
THROUGH THE NIGHT. BOTH THE ETA AND AVN MODELS DIG THE H5 SHORTWAVE
TROF OVER NV/UT SOUTHEAST INTO THE FOUR CORNERS REGION BY 12Z
THURSDAY. AS THE H5 TROF DIGS SOUTHEAST SFC/850MB PRESSURE FALLS
OVER NM AND CO SHOULD BEGIN TO VEER THE LOW-LEVEL WIND FIELDS NORTH
OF THE FRONT. THE SOUTHWARD PUSH ON FRONT SHOULD LESSEN AS THE
LOW-LEVEL WINDS NORTH OF THE FRONT BECOME MORE PARALLEL TO THE
FRONTAL BOUNDARY. SFC CONVERGENCE EAST OF THE DRY LINE AND SOUTH OF
THE FRONTAL BOUNDARY SHOULD BE ENOUGH FOR SCATTERED THUNDERSTORMS TO
DEVELOP OVER THE EASTERN COUNTIES OF THE CWFA THIS EVENING.
THUNDERSTORMS WILL BE HIGH BASED GIVEN  TEMPERATURE...DEW POINT
DEPRESSIONS OVER 30 DEGREES. 0-3KM VERTICAL WIND SHEAR SHOULD BE
SUFFICIENT TO PRODUCE MID-LEVEL MESOCYCLONES IN ANY STORMS THAT DO
DEVELOP OVER THE NORTHEASTERN COUNTIES OF THE CWFA...ANY ROTATING
STORMS MAY PRODUCE LARGE HAIL THIS EVENING. AS THE DRYLINE RETREATS
WEST SCATTERED TO ISOLATED CONVECTION MAY DEVELOP ON THE CAP ROCK
TONIGHT. THE SFC FRONT WILL PUSH NORTH ACROSS THE TX PNHDL TOMORROW
AFTERNOON AS SFC/850MB LOW DEVELOPS OVER EASTERN NM. SOUTHEAST SFC
WINDS WILL ADVECT DEEPER GULF MOISTURE NORTHWEST ACROSS THE CWFA
TOMORROW AFTERNOON EAST OF SFC DRYLINE WHICH SHOULD EXTEND FROM THE
TRIPLE POINT NEAR CVS SOUTH...SOUTHEAST ACROSS THE WESTERN COUNTIES
OF CWFA. ATTM I THINK THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS
TO DEVELOP WILL BE THURSDAY EVENING AND NIGHT AS THE UPPER LOW OVER
THE FOUR CORNERS REGION SLOWLY MOVES EAST INTO NORTHERN NM. THE ETA
MODEL SHOWS THE DRYLINE MOVING EAST INTO THE EASTERN COUNTIES OF
CWFA AFTER 18Z FRIDAY. THE ETA ALSO SHOWS SFC RIDGE BUILDING SOUTH
ACROSS THE WESTERN TX PNHDL ON FRIDAY...THIS SHOULD PUSH SFC COLD FRONT
SOUTH ACROSS THE NORTHWEST CWFA FRIDAY AFTERNOON. THE AVN MODEL
SOLUTION IS ABOUT 12 HOURS SLOWER AVDECTING CLOSED LOW NORTHEAST
FROM THE FOUR CORNERS REGION.  IF THE AVN MODEL SOLUTION IS CORRECT
POPS WILL BE HIGHER ON FRIDAY AND MAY EXTEND INTO SATURDAY.

THE EXTENDED OUTLOOK:  THE MEDIUM RANGE MODELS SHOW THE CLOSED LOW
OVER NM LIFTING NORTHEAST INTO KS BY SATURDAY NIGHT AS A SFC COLD
FRONT MOVES SOUTH ACROSS THE ENTIRE CWFA. SKIES SHOULD CLEAR WITH
COOLER AND DRIER CONDITIONS DEVELOPING ON SATURDAY. TEMPERATURES
SHOULD WARM INTO THE 80S EARLY NEXT WEEK WITH DRY CONDITIONS. THE
MRF SHOWS AN H5 TROF FORMING OVER NM BY TUE. I WILL PLACE IN A
CHANCE OF SHOWER AND THUNDERSTORMS NEXT TUESDAY AND WEDNESDAY.

FRIONA     52/75/55/67 2343
TULIA      55/79/58/69 3353
CHILDRESS  64/80/63/78 4565
BROWNFIELD 57/82/58/82 2232
LUBBOCK    60/81/60/82 3352
ASPERMONT  67/80/66/79 3464

.LUB...NONE.

20

TXZ021>044-021900-

AREA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE LUBBOCK TX
1150 AM CDT WED MAY 2 2001

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS AFTER 4 PM THIS
AFTERNOON MAINLY FOR AREAS EAST OF THE CAPROCK ESCARPMENT.

THE DRYLINE IS EXPECTED TO PUSH EAST TO NEAR A MEMPHIS TO POST LINE
BY LATE AFTERNOON. TEMPERATURES IN THE 90S COMBINED WITH DEWPOINT
TEMPERATURES IN THE UPPER 50S TO LOWER 60S EAST OF THE DRYLINE MAY
RESULT IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING. SOME OF THE THUNDERSTORMS COULD BECOME SEVERE
WITH STRONG WINDS AND HAIL TO THE SIZE OF GOLFBALLS.

IN ADDITION...AN ISOLATED TORNADO MAY BE POSSIBLE IN THE NORTHERN
ROLLING PLAINS TO THE NORTH OF US HIGHWAY 70. LOW LEVEL WINDS MAY BE
MORE CONDUCIVE TO TORNADO DEVELOPMENT IN THIS AREA DUE TO ITS
PROXIMITY TO A DEVELOPING SURFACE LOW AND SOUTHWARD MOVING COLD
FRONT.

SPOTTER ACTIVATION MAY BE REQUIRED LATE THIS AFTERNOON AND EVENING.