Flash Flood Warning 99, NWS Midland/Odessa, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
341 PM CDT MON AUG 2 1999

SHORT TERM...
SLOW MOVING THUNDERSTORMS PRODUCING HEAVY RAINS CONTINUE ACROSS MUCH
OF THE PERMIAN BASIN EXTENDING SOUTHWESTWARD INTO THE DAVIS
MOUNTAINS.  ALOFT...THE UPPER TROPOSPHERIC LOW CONTINUES TO MEANDER
OVER THE NORTHERN BASIN SOMEWHERE AROUND LAMESA.  EARLIER CONVECTION
HAS STABILIZED THE COLUMN OVER THE NORTHERN BASIN...BUT CONVECTION
IS BEGINNING TO REDEVELOP TO THE NORTH OF THE CWFA.  THE COLUMN IS
FORECAST TO REMAIN VERY MOIST FOR THIS TIME OF YEAR...AND WITH
OUTFLOW BOUNDARIES SERVING AS FOCUSING MECHANISMS...REDEVELOPMENT
IS LIKELY OVER THE NORTHERN HALF OF THE CWFA.  ANTECEDENT RAINFALL
OVER THE NORTHERN BASIN...APPROACHING SIX INCHES IN PLACES SINCE
SUNDAY...AND THE THREAT OF HEAVY RAINFALL TONIGHT WARRANTS THE
ISSUANCE OF A FLASH FLOOD WATCH FOR AREAS GENERALLY NORTHEAST OF A
FORT STOCKTON TO BALMORHEA LINE.

AS WAS THE CASE THE PAST FEW DAYS...EXPECTED SHEAR AND INSTABILITY
ACROSS THE AREA WILL SUPPORT A MULTICELL CONVECTIVE MODE.  WHILE WE
CANNOT RULE OUT ONE OR TWO MICROBURSTS NEARING SEVERE CRITERION...THE
THREAT OF SEVERE CONVECTION IS LOW ENOUGH TO PRECLUDE MENTION IN THIS
FORECAST PACKAGE.

LONG TERM...
LITTLE CHANGE IS EXPECTED THROUGH THE MIDDLE OF THE WORK WEEK.  AN
UPPER DEFORMATION ZONE...NOT AN EASTERLY WAVE...PRESENTLY OVER EAST
TEXAS WILL TRANSLATE WESTWARD TONIGHT AND MERGE WITH THE UPPER LOW
OVER THE SOUTHERN PLAINS TUESDAY.  THE COLUMN WILL REMAIN MOIST AS
PRECIP WATER VALUES WILL REMAIN AT OR ABOVE 3 CM...AND SHOULD BE
MARGINALLY UNSTABLE.  A PLETHORA OF OUTFLOW BOUNDARIES LEFT OVER FROM
EARLIER CONVECTION WILL PROVIDE FOCI FOR THUNDERSTORM DEVELOPMENT
JUST ABOUT ANYWHERE IN THE CWFA.  DEPENDING ON THE EVOLUTION OF HEAVY
RAINS TONIGHT...THE THREAT OF FLASH FLOODING MAY CONTINUE...
NECESSITATING A CONTINUANCE OF THE FLASH FLOOD WATCH.  GUIDANCE
DOESNT HAVE A CLUE THIS AFTERNOON...KEEPING THE AREA MORE OR LESS
DRY...THUS WELL KEEP POPS IN THE CHANCE CATEGORY AREAWIDE THROUGH
WEDNESDAY.  THIS WILL IN TURN KEEP AFTERNOON HIGHS ABOUT ONE OR TWO
CATEGORIES COOLER THAN WHAT THE MACHINE THINKS WILL HAPPEN.

REAL LONG TERM...
MORE OF THE SAME THROUGH THE EXTENDED AS WE REMAIN IN A MONSOONAL
PATTERN.  WE SHOULD SEE CONVECTION BECOME MORE DIURNALLY DRIVEN
TOWARD THE END OF THE WORK WEEK WITH TEMPERATURES REMAINING CLOSE TO
NORMAL.

THATS A WRAP...THANKS FOR COORDINATION LBB...SJT...AND WGRFC...
AND SLUGGING PERCENTAGES FOLLOW...70.

THE PRELIMINARY GUIDANCE BELOW IS FOR COORDINATION PURPOSES ONLY.
OFFICIAL FORECASTS ARE CONTAINED WITHIN THE WEST TEXAS/SOUTHEASTERN
NEW MEXICO ZONE FORECAST.

MAF  69/86/69/88    5544
LSA  66/85/68/87    5544
E41  68/87/69/89    5544
6R6  69/88/70/90    5444
MRF  61/81/62/82    5444
CNM  68/89/70/91    4343

.MAF...
TX...FLASH FLOOD WATCH TONIGHT NORTHEAST OF A BALMORHEA TO FORT
     STOCKTON LINE...TXZ045>048-050>053-058>063-067>070-075.
NM...FLASH FLOOD WATCH TONIGHT FOR LEA COUNTY...NMZ029.