Flash Flood Warning 17, NWS San Angelo, TX

000 
WGUS74 KSJT 110730
FFSSJT
TXC435-110800-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN ANGELO TX
228 AM CDT TUE MAY 11 2004

...A FLASH FLOOD WARNING REMAINS IN EFFECT FOR SUTTON COUNTY UNTIL 
300 AM CDT...

AT 225 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE
THUNDERSTORMS WITH THE HEAVIER RAIN HAVE MOVED EAST OUT OF SUTTON 
COUNTY. DOPPLER RADAR ESTIMATES THAT 2 TO 4 INCHES OF RAIN HAVE 
FALLEN ACROSS PARTS OF THE SOUTHERN HALF OF SUTTON COUNTY. SHOWERS 
AND A FEW THUNDERSTORMS WILL CONTINUE PAST 300 AM...WITH ADDITIONAL 
RAINFALL AMOUNTS UP TO ONE HALF INCH. 

SOME DRAWS AND LOW WATER CROSSINGS COULD BE FLOODED. MOTORISTS 
SHOULD BE ESPECIALLY CAUTIOUS ALONG HIGHWAYS 277...1989...AND 189 IN 
SOUTHERN SUTTON COUNTY. WATER LEVELS WILL RECEDE OVERNIGHT.  

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE 
DANGERS OF FLOODS AND FLASH FLOODS. MOST DEATHS IN FLASH FLOODING 
OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS BRIDGES...DIPS...OR 
LOW SPOTS IF WATER COVERS THE ROADWAY. NEVER TRY TO CROSS A FLOWING 
STREAM...EVEN A SMALL ONE...ON FOOT.

$$

19

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN ANGELO TX
649 PM CDT MON MAY 10 2004

.UPDATE...
DID A QUICK UPDATE TO THE GRIDS TO INCREASE PRECIP CHANCES TONIGHT
ACROSS WESTERN AND SOUTHWESTERN COUNTIES AS SHOWERS AND THUNDERSTORMS
CONTINUE TO DEVELOP AND MOVE SLOWLY EASTWARD WITH AN UPPER LEVEL
SHORT WAVE MOVING ACROSS THE BIG BEND. WILL SEE SOME DECREASE IN
THUNDERSTORMS WITH SUNSET...BUT ENOUGH INSTABILITY OVERNIGHT TO
CONTINUE THE POSSIBILITY OF STORMS.  OTHERWISE...NO OTHER CHANGES AT
THIS TIME.

&&

.PREV DISCUSSION...
TYPICAL MIDDLE OF MAY WEATHER EXPECTED FOR WEST CENTRAL TX FOR THE
NEXT SEVEN DAYS. FORECAST IS NOT PARTICULARLY SIMPLE...WITH WEAK
SHORTWAVES EMBEDDED IN SOUTHWEST FLOW ALOFT ACTING UPON A PERSISTENT
WEAKLY CAPPED LOWER ATMOSPHERE. PRIMARY FORECAST CONCERN REMAINS RAIN
CHANCES.

LATEST GOES VISIBLE IMAGERY INDICATED A SHORTWAVE TROF SPINNING OVER
FAR WEST TX. MIDLEVEL-BASED SHOWERS HAD FORMED OVER THE TRANS-PECOS
THIS MORNING...AND CONTINUED AT MIDAFTERNOON. THESE THUNDERSTORMS
WILL BECOME INCREASINGLY SURFACE-BASED THROUGH THE REMAINDER OF THE
AFTERNOON AND EXPECT A FEW TO DRIFT INTO CROCKETT COUNTY. GFS AND
MESOETA PROG THE SHORTWAVE TO MOVE INTO WEST CENTRAL TX THIS EVENING
LATE TONIGHT. THIS MAY HELP SUSTAIN ELEVATED CONVECTION AFTER A
30-35KT LOW LEVEL JET BECOMES ESTABLISHED MID TO LATE EVENING. RAIN
CHANCES TUESDAY WILL BE BEST OVER THE EASTERN HALF OF THE FORECAST
AREA...BASED ON THE EXPECTED POSITION OF THE SHORTWAVE TROF. WITH
WEAK SHEAR AND MIDLEVEL LAPSE RATES LESS THAN 7 C/KM...SEVERE
THREAT WILL BE LIMITED.

UPPER LEVEL LONGWAVE TROF WILL DIG INTO THE NORTHERN ROCKIES BY
EARLY THURSDAY...BEFORE LIFTING INTO CENTRAL CANADA. ADDITIONAL
ENERGY DROPPING SOUTHEAST INTO THE GREAT BASIN WILL HELP MAINTAIN A
LOW AMPLITUDE LONGWAVE TROF OVER THE INTERMOUNTAIN WEST THURSDAY AND
FRIDAY. FORECAST FOR WEST CENTRAL TX BECOMES A LITTLE MORE
PROBLEMATIC BY LATE THURSDAY...AS A SURFACE COLD FRONT IS PROGGED BY
THE GFS TO ENTER THE TX PANHANDLE...AS A SURFACE DRYLINE EXTENDS
THROUGH THE PERMIAN BASIN INTO FAR WEST TX. ETA APPEARS TO
PREMATURELY BRING THE COLD FRONT INTO WEST CENTRAL TX THURSDAY
AFTERNOON. WITH SOUTHWEST FLOW ALOFT AND A PERSISTENT LEE-SIDE
SURFACE PRESSURE TROF OUT WEST...WE FAVOR THE SLOWER GFS SOLUTION.
THIS WILL KEEP WEST CENTRAL TX IN THE UNSTABLE WARM SECTOR...WITH AS
YET UNSEEN MESOSCALE BOUNDARIES TO FOCUS DEEP CONVECTION ON. A LOT OF
UNCERTAINTY EXISTS...BUT SUSPECT A BETTER CHANCE OF RAIN TO OCCUR
OVER WEST CENTRAL TX THURSDAY NIGHT INTO FRIDAY...WITH A TRIPLE POINT
DROPPING INTO WEST CENTRAL TX AND STORMS POSSIBLY LIFTING OFF OF THE
DRYLINE AND BECOMING ELEVATED DURING THE EVENING.

GFS MODEL GENERATES QPF ALONG THE STALLED SURFACE FRONT OVER WEST
CENTRAL TX ON FRIDAY...WITH AN MCS DEVELOPING ALONG THE FRONT FRIDAY
NIGHT INTO EARLY SATURDAY. WILL HOLD OFF ON THIS SOLUTION...DUE TO
MODEL UNCERTAINTY. WILL MAINTAIN SLIGHT CHANCE POPS FOR EARLY IN THE
WEEKEND. THANKS TO FWD...MAF..EWX AND LUB FORECAST OFFICES FOR
COORDINATION.

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

08

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
119 PM CDT MON MAY 10 2004

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-140-
154-155-168>170-111818-
BROWN TX-CALLAHAN TX-COKE TX-COLEMAN TX-CONCHO TX-CROCKETT TX-
FISHER TX-HASKELL TX-IRION TX-JONES TX-KIMBLE TX-MASON TX-
MCCULLOCH TX-MENARD TX-NOLAN TX-RUNNELS TX-SAN SABA TX-SCHLEICHER TX-
SHACKELFORD TX-STERLING TX-SUTTON TX-TAYLOR TX-THROCKMORTON TX-
TOM GREEN TX-
119 PM CDT MON MAY 10 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL TEXAS.

.DAY ONE...

ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE
WESTERN PORTIONS OF WEST CENTRAL TEXAS THIS AFTERNOON AND EVENING.
ONE OR TWO OF THESE THUNDERSTORMS MAY APPROACH SEVERE LEVELS THIS
AFTERNOON...HOWEVER THE THREAT FOR ANY ORGANIZED SEVERE WEATHER IS
VERY LOW.

.DAYS TWO THROUGH SEVEN...

THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE ON TUESDAY AND THURSDAY
AFTERNOONS. THE THUNDERSTORMS TUESDAY AFTERNOON APPEAR THAT THEY WILL
BE DISORGANIZED AS WELL AND ONLY ONE OR TWO MAY APPROACH SEVERE
LEVELS. THERE IS A BETTER CHANCE THAT THE THUNDERSTORMS ON THURSDAY
COULD ORGANIZE INTO MORE OF A SEVERE WEATHER THREAT AS THE UPPER
LEVEL PARAMETERS COME INTO PLAY ALLOWING FOR BETTER THUNDERSTORM
ORGANIZATION.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED THIS AFTERNOON OR TONIGHT DUE
TO THE LOW PROBABILITY OF SEVERE WEATHER.

27/BRAZZELL