Severe Thunderstorm Warning 89, NWS San Angelo, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
143 PM CDT WED MAY 21 1997

LOW CLOUDS HAVE PERSISTED ALL DAY ACROSS WEST CENTRAL TEXAS
RESULTING IN LITTLE AFTERNOON HEATING.  LATEST SATELLITE SHOWING
MID LEVEL DRYING ACROSS WEST TEXAS MOVING EASTWARD BEHIND A WEAK VORT
MAX MOVING ACROSS WEST TEXAS. REMNANTS OF STATIONARY FRONT DIFFICULT
TO PICK OUT BUT STILL CAN BE SEEN ACROSS SOUTH TEXAS. RADAR SHOWING A
FEW SHOWERS AND THUNDERSTORMS MOVING INTO SOUTHERN COUNTIES.  DEEP
MOISTURE IN PLACE WITH PRECIPITABLE WATER LEVELS ABOVE NORMAL.

FOR THIS EVENING THROUGH TONIGHT...SCATTERED THUNDERSTORMS WILL
BE LIKELY MAINLY OVER EDWARDS PLATEAU AND CONCHO VALLEY AS
LINE OF SHOWERS CONTINUES TO MOVE NORTHWARD AND IS SHOWING SIGNS OF
STRENGTHENING. COULD SEE FURTHER DEVELOPMENT AS MID LEVEL DRYING
HELPS TO FURTHER DESTABILIZE AIR. ALSO...CLOUD/NO CLOUD LINE MOVING
IN FROM THE WEST COULD RESULT IN DIFFERENTIAL HEATING BOUNDARY WHICH
COULD HELP FIRE STORMS.  GREATEST THREAT WILL BE FROM LOCALIZED
HEAVY RAINFALL AS LITTLE WIND IN THE UPPER LEVELS WILL RESULT IN
SLOW MOVEMENT.  HOWEVER...COULD SEE ISOLATED SEVERE HAIL WITH THE
INCREASING INSTABILITY.

A SERIES OF WEAK VORT MAXES WILL CONTINUE TO MOVE ACROSS WEST TEXAS
THROUGH THE NEXT 24 HOURS...WITH THE BEST LIFT ACROSS WEST CENTRAL
TEXAS TOMORROW AFTERNOON. DEEP MOISTURE AND MARGINAL INSTABILITY WILL
CONTINUE TO BRING CHANCES OF PRECIP.  REMNANTS OF THE STATIONARY
FRONT WASHED OUT...BUT OUTFLOW BOUNDARIES FROM THUNDERSTORMS THIS
EVENING COULD HELP INITIATE CONVECTION TOMORROW.

CLOUD COVER WILL KEEP LOWS WARM TONIGHT AND HIGHS COOL AGAIN
TOMORROW...SO WILL GO WITH WARMER NGM LOWS TONIGHT AND TOWARD COOLER
AVTIATION HIGHS TOMORROW.

ABI 059/072 34
JCT 060/077 44
SJT 057/074 44

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TXZ049-053-054-064>066-071>073-076>078-113-114-127-128-139-140-
154-155-168>170-221320-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
213 PM CDT WED MAY 21 1997

...SCATTERED NON SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS WEST
CENTRAL TEXAS THIS AFTERNOON THROUGH THIS EVENING...

ABUNDANT MOISTURE AND WEAK INSTABILITY REMAIN IN PLACE ACROSS WEST
CENTRAL TEXAS THIS AFTERNOON.  A LINE OF SHOWERS AND THUNDERSTORMS
HAS DEVELOPED ACROSS THE NORTHERN EDWARDS PLATEAU AND NORTHWEST HILL
COUNTRY EARLY THIS AFTERNOON. THIS LINE OF STORMS WILL CONTINUE TO
MOVE NORTHWARD INTO THE CONCHO VALLEY AND HEARTLAND THROUGH THE
EVENING. THESE STORMS WILL LIKELY INCREASE IN STRENGTH AS AN UPPER
LEVEL DISTURBANCE MOVES ACROSS THE AREA THIS EVENING. WITH WEAK
VERTICAL WIND SHEAR IN THE ATMOSPHERE...THESE STORMS ARE NOT EXPECTED
TO BECOME SEVERE. HOWEVER...HEAVY RAINFALL OF AN INCH OR MORE WILL BE
POSSIBLE WITH SOME OF THE STORMS...AS WELL AS SMALL HAIL AND WIND
GUSTS TO 40 MPH.

SPOTTER ACTIVATION IS NOT ANTICIPATED.
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