Flash Flood Warning 24, NWS Midland/Odessa, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
230 AM CDT MON MAY 24 1999

UPPER LOW REMAINING OVER NRN AZ FOR YET ANOTHER DAY. LATEST
PROGS BEGIN TO SLOWLY LIFT THE LOW OUT ON TUESDAY INTO THE 4 CORNERS
REGION...AND GRADUALLY PROGRESS THE SYSTEM EWD TOWARD THE TX
PANHANDLE BY LATE WED. ONCE THESE SYSTEMS BEGIN TO LIFT OUT THE
MODELS TEND TO DO IT TOO SLOWLY...SO I THINK THE TIMING MAY END UP
BEING JUST A BIT FASTER THAN THE PROGS ARE FORECASTING. WATER VAPOR
IMAGERY REVEALING THE FACT THAT OUR TROPICAL CONNECTION CONTINUES...
WITH A GOOD FETCH OF MID/HIGH LEVEL MOISTURE STREAMING UP FROM THE
SW. THE LOW LEVELS SHOULD REMAIN FAVORABLY MOIST AS WELL. H8 FLOW TO
REMAIN MAINLY SELY ACROSS THE FORECAST AREA THROUGH THE SHORT TERM
PERIOD. THE WEAK FRONTAL BOUNDARY THAT DROPPED DOWN FROM THE NORTH
YESTERDAY HAS WASHED OUT AND BECOME RATHER DIFFUSE...AND IT IS
DIFFICULT TO TELL EXACTLY WHERE ITS LOCATED...AND OUTFLOW BOUNDARIES
HAVE FURTHER COMPLICATED THE PICTURE. UPPER LEVEL WINDS REMAINING
DIFLUENT...AND IT LOOKS AS IF YET ANOTHER SHORTWAVE WILL PASS ACROSS
THE AREA THIS AFTEROON. THIS HAS PRETTY MUCH BEEN THE CASE FOR THE
PAST SEVERAL DAYS...WITH CONVECTION INITIATING IN THE MOUNTAINS AND
MOVING OFF INTO THE LOWLANDS. THE MAIN DIFFERENCE TODAY WILL BE MORE
FAVORABLE WIND SHEAR. I BELIEVE THE WIND FLOW PATTERNS WOULD BE MORE
FAVORABLE FOR ORGANIZED CONVECTION THIS AFTERNOON AND TONIGHT. H8
WINDS PROGGED TO CONTINUE FROM THE SE...WITH H7 WINDS BECOMING SLY TO
SWLY...AND H5 WINDS NEARLY WLY. UPPER LEVEL WINDS WILL BE STRONGER
THAN YESTERDAY AS WELL. WITH THE LOW LEVEL FLOW REMAINING OUT OF THE
SE...THE DRYLINE SHOULD NOT COME INTO PLAY TODAY.

HOWEVER...THE CHANCES FOR CONVECTION MAY SUFFER ACROSS A GOOD
PORTION OF THE AREA TODAY FROM COOLER SFC TEMPS AND  RELATIVELY WEAK
INSTABILITY...DUE TO MULTIPLE FACTORS...INCLUDING THE FRONTAL
BOUNDARY...A FAIR AMOUNT OF CLOUD COVER THAT IS PROGGED...AND THE
FACT THAT A NUMBER OF LOCATIONS HAVE RECEIVED PCPN. I DO NOT THINK
THIS WILL INHIBIT CONVECTION TOO MUCH ACROSS THE MOUNTAIN AREAS...BUT
IT MAY COME INTO PLAY AS THE CONVECTION MOVES OUT INTO THE PLAINS.
SO...IT LOOKS TO ME AS IF A REPEAT PERFORMANCE IS IN STORE FOR THIS
AFTERNOON AND TONIGHT AS PER THE LAST SEVERAL DAYS...WITH CONVECTION
FORMING IN THE MOUNTAINS AND MOVING INTO THE PLAINS. I THINK THE
STORMS WILL HAVE THE POTENTIAL TO BECOME MORE ORGANIZED AND BETTER
SUSTAINED IN THE AREAS ACROSS THE WRN AND SRN PORTIONS OF THE CWA
WITH THE MORE FAVORABLE WIND SHEAR AND BETTER INSTABILITIES. AND I
THINK THAT THERE WILL BE A CORRESPONDINLY LOWER RISK OF SEVERE
CONVECTION ACROSS THE NRN AND ERN PORTIONS OF THE CWA WITH THE LESS
FAVORABLE INSTABILITY. HOWEVER...IF THE SFC TEMPS DO CLIMB HIGHER
THAN ANTICIPATED TODAY...IT COULD MAKE FOR A VERY ACTIVE AFTERNOON
ACROSS THESE AREAS AS WELL.

BY TUESDAY...AS THE LOW STARTS TO LIFT OUT...THE H7 AND H5 WIND
PATTERNS BECOME MORE WLY...AND H8 WINDS BECOME MORE SLY. I BELIEVE
THIS WILL PERMIT THE DRYLINE TO ADVANCE AND KICK OFF SOME
CONVECTION. MODELS PROG THE ATMOSPHERE TO BE MUCH MORE UNSTABLE...
AND IT LOOKS TO ME LIKE THERE WILL BE A GREATER RISK FOR SEVERE
WEATHER ACROSS THE ENTIRE AREA ON TUESDAY RATHER THAN TODAY. LOOKING
AHEAD INTO THE EXTENDED...WILL KEEP SOME LINGERING CHANCES FOR SCT
CONVECTION ACROSS THE AREA ON WEDNESDAY WITH THE UPPER LOW STILL IN
THE NEIGHBORHOOD...AND WILL REVERT TO A MORE CONSERVATIVE FORECAST
OF ISOLATED CONVECTION FOR THURSDAY AND FRIDAY AS THE LOW CLEARS OUT.

PRELIM NUMBERS...
MAF 88/60/90 333
CNM 85/59/90 344
MRF 82/53/85 322
P07 88/61/90 233

DJK

NMZ027>029-TXZ045>048-050>052-057>063-067>070-074-075-079>082-240500-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE MIDLAND-ODESSA TX
545 AM (445 AM MDT) CDT MON MAY 24 1999

THIS OUTLOOK PERTAINS TO THE FOLLOWING COUNTIES IN WEST TEXAS:

ANDREWS   CULBERSON  GLASSCOCK   MARTIN    REAGAN   UPTON
BORDEN    DAWSON     HOWARD      MIDLAND   REEVES   WARD
BREWSTER  ECTOR      JEFF DAVIS  PECOS     SCURRY   WINKLER
CRANE     GAINES     LOVING      PRESIDIO  TERRELL

AND IN SOUTHEAST NEW MEXICO:

EDDY      LEA

SYNOPSIS:
EARLY TODAY A COLD FRONT STRETCHED ACROSS CENTRAL TEXAS FROM NEAR
SAN ANGELO WESTWARD TO FORT STOCKTON TO THE GUADALUPE MOUNTAINS.
THIS FRONT WILL REMAIN NEARLY STATIONARY TODAY AND TONIGHT AS LOW
PRESSURE  DEVELOPS ALONG THE FRONT ACROSS EXTREME WESTERN TEXAS. LOW
LEVEL CONVERGENCE AND UPSLOPE FLOW ALONG WITH AN UNSTABLE ATMOSPHERE
WILL RESULT IN WIDELY SCATTERED THUNDERSTORM DEVELOPMENT THIS
AFTERNOON ACROSS EXTREME SOUTHEAST NEW MEXICO...DAVIS AND GUADALUPE
MOUNTAINS OF WEST TEXAS. A SUBSTANTIAL SOUTHWEST FLOW ALOFT WILL LIKELY
RESULT IN THESE THUNDERSTORMS MOVING NORTHEAST THIS EVENING AND
TONIGHT INTO THE TRANS-PECOS AND PERMIAN BASIN REGION. STRONG
TURNING OF THE WINDS WITH HEIGHT FROM THE SOUTHEAST AT THE SURFACE
TO WESTERLY IN THE MID LEVELS OF THE ATMOSPHERE SUGGEST THAT
THUNDERSTORMS THAT DO DEVELOP WILL BECOME SEVERE...WITH LARGE HAIL
AND DAMAGING WIND THE MAIN THREAT...WITH ISOLATED TORNADOES POSSIBLE.

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND TONIGHT ACROSS
EXTREME SOUTHEAST NEW MEXICO AND WEST TEXAS.

FOR THE WEST CENTRAL TEXAS OUTLOOK SEE THE PRODUCT LBBSPSSJT ISSUED
BY NWS SAN ANGELO (WWUS35 KSJT).

JMC