Severe Thunderstorm Warning 133, NWS San Angelo, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
1125 AM CDT SAT MAY 27 2000

COLD FRONT/OUTFLOW BNDRY ENTERING NWRN BIG COUNTRY/FAR NWRN CONCHO VLLY
ACCORDING TO VSBL SATELLITE LOOPS/SFC OBSERVATIONS. EXPECT THE BNDRY TO
SLOW DOWN TO A CRAWL OR STALL THIS AFTERNOON ACROSS THE SERN BIG CNTRY
AND NWRN CONCHO VLLY DUE TO DAYTIME EFFECTS AND APPROACH OF POSITIVELY
TILTED VORT LOBE. UPDATED THE ZONES TO INCREASE TSTM CHANCES SLIGHTLY
AND MENTION POSSIBLE SEVERE ACROSS THE SERN BIG COUNTRY/CONCHO VLLY/
HEARTLAND. STEERING WINDS ALOFT FORECAST TO BE UNDER 15 KTS...SO LOCALLY
HEAVY RAIN A GOOD POSSIBILITY.

.SJT...NONE.

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TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-
140-154-155-168>170-271500-

WEST CENTRAL TEXAS THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SAN ANGELO TX
911 AM CDT SAT MAY 27 2000

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND EVENING ACROSS THE NORTHERN BIG COUNTRY AND A SLIGHT RISK
ELSEWHERE IN WEST CENTRAL TEXAS...

A COLD FRONT IS EXPECTED TO DROP INTO THE NORTHWEST BIG COUNTRY BY
LATE MORNING AND INTO THE CONCHO VALLEY BY LATE AFTERNOON. ABUNDANT
LOW LEVEL MOISTURE WILL BE IN PLACE AHEAD OF THIS FRONT. THE
ATMOSPHERE WILL BE VERY UNSTABLE ALONG AND SOUTH OF THE FRONT.

THERE IS A CHANCE OF THUNDERSTORMS ACROSS THE BIG COUNTRY...
HEARTLAND AND CONCHO VALLEY...MAINLY IN THE LATTER HALF OF THE
AFTERNOON AND THE EVENING. THE DEGREE OF INSTABILITY WILL LIKELY BE
HIGH ENOUGH TO OVERCOME THE LACK OF WIND SHEAR AND WEAK LOW LEVEL
FLOW. STORMS SHOULD MOVE SLOWLY SOUTHEAST...PRODUCING LOCALIZED
RAINFALL AMOUNTS IN EXCESS OF TWO INCHES.

THE MODERATE RISK AREA IS NORTH OF INTERSTATE 20. SOME OF THE
THUNDERSTORMS THAT DEVELOP HERE COULD BE SEVERE...WITH THE THREATS
BEING LARGE HAIL...DAMAGING WINDS...HEAVY RAIN AND AN ISOLATED
TORNADO.

THE SLIGHT RISK AREA INCLUDES OTHER PORTIONS OF WEST CENTRAL TEXAS
EXCEPT THE FAR WESTERN CONCHO VALLEY AND MUCH OF CROCKETT COUNTY.
A FEW THUNDERSTORMS IN THE SLIGHT RISK AREA MAY BE SEVERE...PRODUCING
LARGE HAIL AND/OR DAMAGING WINDS.

SPOTTER ACTIVATION WILL LIKELY BE NEEDED..

FOR THE SOUTHWEST TEXAS AND SOUTHEAST NEW MEXICO OUTLOOK SEE
PRODUCT LBBSPSMAF. FOR THE SOUTH PLAINS OUTLOOK SEE PRODUCT
LBBSPSLBB. FOR THE CENTRAL OKLAHOMA OUTLOOK SEE PRODUCT OKCSPSOKC.
FOR THE NORTH TEXAS OUTLOOK SEE PRODUCT FTWSPSFTW. FOR THE SOUTH
CENTRAL TEXAS OUTLOOK SEE PRODUCT SATSPSSAT.

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TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-
140-154-155-168>170-272300-

WEST CENTRAL TEXAS THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
127 PM CDT SAT MAY 27 2000

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING ACROSS MOST OF WEST CENTRAL TEXAS...

AT EARLY AFTERNOON...A WEAK COLD FRONT WAS IN THE BIG COUNTRY AND
NORTHWEST CONCHO VALLEY. THIS BOUNDARY EXTENDED FROM NEAR WICHITA
FALLS...TO NORTH OF ABILENE...TO STERLING CITY. THE ATMOSPHERE WAS
QUITE MOIST AND UNSTABLE SOUTH OF THE BOUNDARY WITH DEWPOINTS AROUND
70 DEGREES.

AS AN UPPER LEVEL TROUGH APPROACHES WEST TEXAS...THE BOUNDARY IS
EXPECTED TO MOVE SLOWLY SOUTHEAST...EXTENDING FROM OZONA...TO NEAR SAN
ANGELO...TO BALLINGER...TO CROSS PLAINS BY LATE AFTERNOON. STRONG LOW
LEVEL CONVERGENCE ALONG THE BOUNDARY...COMBINED WITH A VERY UNSTABLE
ATMOSPHERE AND ADEQUATE DIRECTIONAL WIND SHEAR WILL PRODUCE SCATTERED
THUNDERSTORMS THROUGH THIS EVENING.

THE SLIGHT RISK AREA IS GENERALLY EAST OF A LINE FROM SNYDER...
TO MERTZON...TO OZONA. SOME STORMS ACROSS THE SOUTHEAST HALF OF THE
BIG COUNTRY...THE CONCHO VALLEY AND HEARTLAND WILL LIKELY BECOME
SEVERE...PRODUCING LARGE HAIL...DAMAGING WINDS...AND LOCALLY HEAVY
RAINFALL SINCE STEERING WINDS ALOFT WILL BE LIGHT. LOCALIZED RAINFALL
AMOUNTS IN EXCESS OF TWO INCHES ARE POSSIBLE ALONG WITH ISOLATED
TORNADOES. STORM MOTION WILL BE TO THE SOUTHEAST AT 5 TO 15 MPH.

ACROSS THE NORTHERN EDWARDS PLATEAU AND NORTHWEST HILL COUNTRY...
THERE WILL BE A CHANCE OF THUNDERSTORMS PRIMARILY IN THE EVENING.
SEVERE THUNDERSTORMS ARE LESS LIKELY HERE.

SPOTTER ACTIVATION WILL LIKELY BE NEEDED..

FOR THE SOUTHWEST TEXAS AND SOUTHEAST NEW MEXICO OUTLOOK SEE
PRODUCT LBBSPSMAF. FOR THE SOUTH PLAINS OUTLOOK SEE PRODUCT
LBBSPSLBB. FOR THE CENTRAL OKLAHOMA OUTLOOK SEE PRODUCT OKCSPSOKC.
FOR THE NORTH TEXAS OUTLOOK SEE PRODUCT FTWSPSFTW. FOR THE SOUTH
CENTRAL TEXAS OUTLOOK SEE PRODUCT SATSPSSAT.

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