Tornado Warning 20, NWS San Angelo, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
158 PM CDT WED SEP 18 1996

SHOWERS AND THUNDERSTORMS CONTINUING ACROSS THE BIG COUNTRY...WITH A
FEW OTHERS TRYING TO DEVELOP OVER THE CONCHO VALLEY AND HEARTLAND.
EARLIER STORMS HAVE LEFT SEVERAL OUTFLOW BOUNDARIES ACROSS THE
NORTHERN THIRD OF THE AREA...WHILE LOW CLOUDS HAVE CUT DOWN ON SOME
OF THE INSTABILITY ACROSS THE CENTRAL AND SOUTHERN SECTIONS.

BELIEVE LOW CLOUDS WILL CONTINUE TO BREAK AND INSTABILITIES WILL
CONTINUE TO INCREASE. NICE MOISTURE CONVERGENCE TAKING SHAPE ACROSS
THE CONCHO VALLEY THIS AFTERNOON...AND STILL BELIEVE STORM
DEVELOPMENT LIKELY ALONG THE OUTFLOW BOUNDARIES ACROSS THE HEARTLAND
...NORTHERN CONCHO VALLEY...AND THE BIG COUNTRY. IN ADDITION...WATER
VAPOR SATELLITE LOOP SHOWING ANOTHER SHORTWAVE APPROACHING WEST
TEXAS THIS AFTERNOON. THINK MORE STORMS WILL DEVELOP WEST OF THE
AREA...MOVING NORTHEAST ACROSS THE WESTERN BIG COUNTRY ONCE AGAIN.
DEVELOPMENT LIKELY TO TAKE PLACE ALONG A WEAK SURFACE TROUGH LOCATED
FROM THE TEXAS PANHANDLE TO WEST OF LUBBOCK TO WEST OF MIDLAND AT
18Z.

KSJT WIND PROFILE SHOWING DECENT SHEAR...WITH PROJECTED CAPES IN THE
2000 TO 3000 RANGE...POSSIBILITY OF SEVERE LOOKS REASONABLE.
SIMILAR TO LAST NIGHT...THINK BEST CHANCES OVER THE NORTH...CLOSER
TO THE UPPER LEVEL DYNAMICS AND LOW LEVEL BOUNDARIES...WITH LESSER
CHANCES TO THE SOUTH. NUMBERS SUBJECT TO LAST MINUTE CHANGES DUE TO
LAST MINUTE RADAR TRENDS.

ABI 070/086 33
SJT 073/088 22

PMCCULLOUGH

TXZ049-053-054-064>066-071>073-076>078-113-114-127-128-139-140-
154-155-168>170-191335-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
230 PM CDT WED SEP 18 1996

...SEVERE THUNDERSTORMS ARE POSSIBLE OVER WEST CENTRAL TEXAS THIS
AFTERNOON AND TONIGHT...

A VERY MOIST AND UNSTABLE AIR MASS WILL REMAIN IN PLACE ACROSS ALL
OF WEST CENTRAL TEXAS THROUGH TONIGHT. EARLY MORNING THUNDERSTORMS
HAVE LEFT SEVERAL OUTFLOW BOUNDARIES DRAPED ACROSS THE NORTHERN
HEARTLAND AND THE BIG COUNTRY...WHICH WILL ACT TO HELP FOCUS
THUNDERSTORM DEVELOPMENT ACROSS THESE AREAS THIS AFTERNOON. IN
ADDITION...A STRONG UPPER LEVEL DISTURBANCE WILL APPROACH THE AREA
EARLY THIS EVENING...POSSIBLY DEVELOPING THUNDERSTORMS ACROSS THE
REMAINDER OF THE AREA.

ATMOSPHERIC CONDITIONS SUGGEST THAT ANY STORM THAT DOES
DEVELOP MAY QUICKLY BECOME SEVERE...WITH LARGE HAIL...DAMAGING
WINDS...AND TORRENTIAL RAINFALL THE PRIMARY THREATS. HOWEVER...THERE
DOES APPEAR TO BE SUFFICIENT SHEAR THROUGHOUT THE ATMOSPHERE FOR THE
FORMATION OF SUPERCELLS...AND A FEW ISOLATED TORNADOES. THE AREA MOST
LIKELY TO SEE THE MAJORITY OF THE SEVERE WEATHER WILL NORTH OF A
LINE FROM BROWNWOOD TO COLORADO CITY...WITH LESSER CHRANCES ACROSS THE
REMAINDER OF THE AREA.

SPOTTER ACTIVATION WILL LIKELY BE NEEDED.

PMCCULLOUGH