Flash Flood Warning 67, NWS San Angelo, TX

WEST CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
616 AM CDT SUN JUL 14 2002

UPDATED TO ADD MENTION OF ISOLATED THUNDERSTORMS IN THE BIG COUNTRY
AND TO INCREASE POPS IN THE HEARTLAND. 11Z RADAR AND SATELLITE
OBSERVATIONS INDICATE LOW LEVEL CONVERGENCE ALONG A TROUGH
STRETCHING FROM NEAR SWEETWATER THROUGH THE HEARTLAND. SHOWERS AND
THUNDERSTORMS ARE MORE NUMEROUS IN THE HEARTLAND THAN PREVIOUSLY
THOUGHT. A FLOOD WATCH MAY BE NEEDED IN THE HEARTLAND WITH HEAVY
RAINFALL OBSERVED (UP TO AROUND 2 INCHES IN A FEW LOCATIONS) AND
SOME TRAINING OCCURRING IN THE HEARTLAND ALONG THE BOUNDARY. WILL
CONTINUE TO MONITOR.

BELOW IS THE EARLY MORNING DISCUSSION.
***********************************

07Z ANALYSIS SHOWS A STRONG UPPER LEVEL RIDGE CONTINUES TO DOMINATE
THE WESTERN STATES. MEANWHILE AN UPPER LEVEL TROUGH CONTINUES TO
STRETCH FROM NEW ENGLAND TO TEXAS. A DIFFUSE SURFACE FRONT STRETCHES
FROM WEST OF AMARILLO...SOUTHEAST TO BETWEEN CHILDRESS/WICHITA FALLS
AND THE BIG COUNTRY...THEN OFF TO THE EAST ALONG THE RED RIVER.

TODAY AND TONIGHT...
DESPITE THE SURFACE FRONT NORTH OF THE BIG COUNTRY...PLENTY OF LEFT
OVER OUTFLOW BOUNDARIES CONTINUE TO MEANDER ACROSS WEST CENTRAL
TEXAS. THIS WILL PROVIDE ENOUGH OF A KICK FOR ISOLATED/SCATTERED
THUNDERSTORMS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WHERE
THE BEST MOISTURE REMAINS. WITH DRY MID/UPPER LEVEL AIR CONTINUING
TO SLOWLY SLIDE SOUTH INTO THE REGION...AN ISOLATED SEVERE STORM
COULD DEVELOP AS THE PREVIOUS COUPLE OF DAYS. HOWEVER LITTLE UPPER
LEVEL DYNAMICS WILL REMAIN AS THE UPPER LEVEL SUPPORT (WEAK JET)
LIFTS OFF TO THE NORTHEAST. THIS BOUNDARY BETWEEN THE DRY AND MOIST
MID/UPPER LEVEL AIR WILL BE THE MOST LIKELY LOCATION FOR INITIAL
STORMS TO DEVELOP TODAY. THIS BOUNDARY WILL BE ACROSS THE CENTRAL
COUNTIES EARLY ON...BEFORE WORKING A BIT FURTHER SOUTH LATER IN THE
DAY. BY THIS EVENING A FEW THUNDERSTORMS WILL BE KICKING OFF ALONG
ANY OUTFLOW BOUNDARIES MORE LIKELY FURTHER SOUTH CLOSER TO
INTERSTATE 10. ACTIVITY SHOULD DIMINISH ONCE AGAIN OVERNIGHT.

MONDAY AND TUESDAY...
MONDAY ISOLATED THUNDERSTORMS CAN BE EXPECTED WITH ONLY LEFT OVER
OUTFLOW BOUNDARIES TO HELP TRIGGER THEM. HOWEVER MONDAY NIGHT INTO
TUESDAY MUCH BETTER ACTIVITY CAN BE EXPECTED WITH A WEAK LOW LEVEL
JET BEGINNING TO DEVELOP AND PROVIDING LOW LEVEL CONVERGENCE OVER
THE FORECAST AREA. ALSO WEST CENTRAL TEXAS BECOMES WITHIN THE RIGHT
ENTRANCE REGION OF ANOTHER (ALBEIT WEAK) UPPER LEVEL JET...SIMILAR
TO OR SLIGHTLY BETTER THAN SATURDAY/S CONDITIONS. THEREFORE WILL
CONTINUE THE BETTER CHANCE OF RAIN MONDAY NIGHT AND TUESDAY.

IN THE EXTENDED...
BY WEDNESDAY THE UPPER LEVEL DYNAMICS SLIDE OFF TO THE NORTHEAST.
HOWEVER A WITH THE AN UPPER LEVEL TROUGH CONTINUING TO LINGER ACROSS
THE REGION...AND SOME OUTFLOW BOUNDARIES MEANDERING ABOUT...ISOLATED
ACTIVITY CAN STILL BE EXPECTED ON WEDNESDAY. THURSDAY THROUGH
SATURDAY MOST MODELS AGREE ON AN OVERALL RIDGE STRETCHING FROM
FLORIDA THROUGH THE HIGH PLAINS. HOWEVER DEPENDING ON WHICH MODEL
THEY ALSO ALL SHOW A WEAKNESS IN THE RIDGE STRETCHING FROM THE
NORTHEAST STATES TO THE SOUTHWEST TOWARDS TEXAS. IT DOES APPEAR ALL
MODELS AGREE ON THE RIDGE BEING SUFFICIENTLY STRONG TO STIFLE ANY
POSSIBLE SHOWER ACTIVITY. THEREFORE WILL CONTINUE WITH THE DRY
FORECAST. ONLY SLIGHTLY WARMER TEMPERATURES APPEAR IN ORDER GIVEN
THE MINIMAL VARIATION IN 850MB TEMPS THROUGH THE WEEK.

ABI 091/067/090/071 1123
SJT 092/068/092/072 2224
JCT 091/070/092/072 3234

.SJT...NONE

24

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-140-
154-155-168>170-142330-

WEST CENTRAL TEXAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
630 AM CDT SUN JUL 14 2002

...LOCALIZED FLOODING POSSIBLE ACROSS THE NORTHWEST HILL COUNTRY AND
THE HEARTLAND FLOODING

THE REMNANTS OF A WEAK FRONT...DAYTIME HEATING...OUTFLOW
BOUNDARIES...AND PLENTY OF MOISTURE WILL CAUSE SCATTERED STRONG
THUNDERSTORMS TO DEVELOP THROUGH TODAY.

SOME OF THESE THUNDERSTORMS WILL CONTINUE TO PRODUCE LOCALLY HEAVY
RAIN...GUSTY WINDS TO 40 MPH...AND DANGEROUS CLOUD TO GROUND
LIGHTNING. AN ISOLATED THUNDERSTORM COULD APPROACH SEVERE LIMITS AND
PRODUCE DAMAGING WINDS.

SPOTTER ACTIVATION...IF ANY...SHOULD BE HIGHLY LOCALIZED.

ADDITIONAL INFORMATION PLEASE SEE STATEMENTS AND OUTLOOKS FROM
NATIONAL WEATHER SERVICE OFFICES ACROSS TEXAS...OKLAHOMA...AND NEW
MEXICO.

26