Flash Flood Warning 12, NWS San Angelo, TX

WEST CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
315 PM CDT MON SEP 3 2001

...SEVERE THUNDERSTORM WATCH FOR ALL OF WEST CENTRAL TEXAS IN EFFECT
UNTIL 8 PM CDT...

12Z ANALYSIS INDICATES A SHARP UPPER LEVEL TROUGH IS DIGGING
SOUTHWEST INTO NEW MEXICO. MODELS DO NOT APPEAR TO BE PICKING UP ON
THE SHARPNESS OF THIS UPPER TROUGH. UPPER LEVEL HIGH PRESSURE IS
CENTERED OVER NORTHERN MEXICO. A SURFACE TROUGH STRETCHES ACROSS THE
PANHANDLE AND FAR WEST TEXAS. CURRENT SATELLITE AND RADAR TRENDS
INDICATE SCATTERED THUNDERSTORMS BREAKING OUT ALONG OUTFLOW
BOUNDARIES FROM ACROSS MUCH OF WEST CENTRAL TEXAS.

TONIGHT...UPPER LEVEL LOW PRESSURE ALONG THE KANSAS/OKLAHOMA BORDER
WILL MAKE ITS WAY SOUTH. THE CURRENT ACTIVITY ACROSS THE BIG COUNTRY
HAS THE POTENTIAL OF DEVELOPING INTO AN MCS. WITH SURFACE DEWPOINTS
IN THE LOW TO MID 70S AND SBCAPES BETWEEN 1500 AND 2200 J/KG ACROSS
THE AREA...THIS ACTIVITY WOULD NOT BE SUPRISED IF A FEW SEVERE
STORMS DEVELOP. THIS IS ALSO INLINE WITH DAY 1 OUTLOOK WITH MOST
COUNTIES IN THE SLIGHT RISK AREA. WITH ENOUGH MID LEVEL DRY AIR AND
SHEAR...LARGE HAIL AND STRONG WIND GUSTS ARE POSSIBLE WITH THESE
STORMS...ESPECIALLY ACROSS THE BIG COUNTRY.
THE RUC AND MESOETA ARE INDICATING LOW LEVEL CONVERGENCE IS SETTING
UP ACROSS THE CENTRAL/SOUTHERN COUNTIES. THEY ARE ALSO INDICATING
STRONG UPPER LEVEL DIVERGENCE AND ALONG WITH A STRONG THETA-E RIDGE
ACROSS THE SOUTHERN COUNTIES. BELIEVE THIS IS OVERDONE SOMEWHAT.
WITH WEAK STEERING WINDS AND WITH PWS INCREASING TO 2.5
INCHES...THE POTENTIAL FOR HEAVY RAINFALL/FLASH FLOODING IS THERE.
THIS SHOULD STILL BE ENOUGH TO ALLOW FOR REDEVELOPMENT OF
THUNDERSTORMS ACROSS THE CENTRAL/SOUTHERN COUNTIES THIS EVENING.
WILL MAKE LAST MINUTE CHANGES DEPENDING ON SATELLITE/RADAR TRENDS.

BY TUESDAY MORNING THE LOW WILL BE CENTERED OVER WEST CENTRAL TEXAS.
A WEAK FRONTAL BOUNDARY WILL ALSO WORK ITS WAY INTO THE REGION. WITH
AMPLE MOISTURE AND AN UPPER LEVEL TROUGH AND LOW LEVEL CONVERGENCE
ACROSS THE AREA WILL INTRODUCE SCATTERED SHOWERS FOR MUCH OF THE
REGION. WITH BKN/OVC SKIES ACROSS THE AREA EXPECT TEMPS TO REACH NO
HIGHER THAN THE LOW TO MID 80S. EXPECT MUCH THE SAME ON WEDNESDAY AS
THE UPPER TROUGH CONTINUES TO HANG AROUND...ALTHOUGH THE SHEAR AXIS
WILL HAVE SHIFTED SLIGHTLY SOUTH.

IN THE EXTENDED...THE MRF INDICATES A WEAKER DRIER TROUGH OVER THE
AREA THAN THE AVN. HOWEVER THE UKMET INITIALIZED THE BEST...AND
AGREES MORE ALONG THE AVN THINKING OF MAINTAINING THE UPPER LEVEL
TROUGH OVER THE AREA FOR SEVERAL DAYS. WITH THIS IN MIND...EXPECT
THE UPPER LEVEL TROUGH WILL VERY SLOWLY SLIDE TO THE
SOUTHEAST...WITH THE AXIS FINALLY SOUTHEAST OF THE AREA BY FRIDAY
MORNING. THIS WILL ALLOW FOR NEAR NORMAL TO SLIGHTLY BELOW NORMAL
TEMPERATURES TO CONTINUE ON THURSDAY. A SLIGHT WARMUP CAN STILL BE
EXPECTED ON FRIDAY. WITH A TROUGH COVERING THE EASTERN TWO THIRDS
OF THE COUNTRY AND HIGH PRESSURE CENTERED TO THE SOUTHWEST...THIS
WILL ALLOW FOR A COLD FRONT TO MAKE ITS WAY INTO THE AREA BY
SATURDAY EVENING. HOWEVER ON MONDAY...WITH THE UPPER LEVEL TROUGH
LIFTING OFF TO THE NORTHEAST THIS WILL ALLOW HIGH PRESSURE TO BUILD
BACK INTO TEXAS FROM THE WEST. THEREFORE EXPECT THE AFFECTS OF THE
FRONT TO BE SHORTLIVED.

PRELIM CCF...

ABI 071/085/071/089 7211
SJT 070/085/069/088 6312
JCT 070/085/069/088 7312

.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>170-032300-

WEST CENTRAL TEXAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
206 PM CDT MON SEP 3 2001

...THERE IS A SLIGHT RISK FOR A FEW SEVERE THUNDERSTORMS ACROSS WEST
CENTRAL TEXAS THIS AFTERNOON INTO TONIGHT...

AN UPPER LEVEL DISTURBANCE WILL MOVE SOUTH INTO NORTH TEXAS LATE
THIS EVENING. WITH WARM AND UNSTABLE AIR ACROSS THE REGION...SHOWERS
AND THUNDERSTORMS WILL OCCUR AS THIS DISTURBANCE APPROACHES. THE
SHOWERS AND STORMS WILL BE MOST NUMEROUS ACROSS THE BIG COUNTRY.

WITH A RATHER UNSTABLE AIRMASS...A FEW STORMS MAY BECOME SEVERE AND
PRODUCE LARGE HAIL AND DAMAGING WINDS.

SPOTTER ACTIVATION MAY BE REQUIRED.

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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