Severe Thunderstorm Warning 64, NWS Brownsville, TX

DEEP SOUTH TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
300 PM CDT SUN AUG 19 2001

SHORT TERM...SOUTH TEXAS CURRENTLY IN THE COL THIS AFTERNOON WITH AN
UPPER HIGH OVER THE FOUR CORNERS REGION OF THE UNITED STATES AND THE
UPPER TROUGH OVER THE OHIO VALLEY EXTENDING SOUTHWEST OVER THE
MISSISSIPPI VALLEY...WITH THE SUBTROPICAL RIDGE OVER THE GULF OF
MEXICO. THIS HAS ALLOWED A WEAK SHORT WAVE TROUGH TO MOVE INTO
CENTRAL TX WITH MOISTURE POOLING ALONG AN OUTFLOW BOUNDARY NORTH OF
DEEP SOUTH TEXAS. CLOUDS AND CONVECTION HAVE SLOWLY MOVED SOUTHEAST
THIS AFTERNOON PER LATEST VISIBLE SATELLITE/RADAR IMAGES AHEAD OF
THE SHORT WAVE. IN ADDITION...A WEAK SEABREEZE HAS DEVELOPED OVER
THE COASTAL COUNTIES OVER THE CWA DESPITE DRY AND MODERATE SOUTH
WINDS. BELIEVE THERE WILL BE ENOUGH MOISTURE ADVECTING SOUTHWARD TO
WARRANT MENTION OF PRECIP TONIGHT. LIKELY TO SEE AN ISOL TSTM IN THE
NORTHERN ZONES THAN SOUTHERN BUT WILL GO ACROSS THE BOARD WITH
UNSTABLE CONDITIONS AT THE SURFACE INDUCED BY HOT SURFACE TEMPS.
OTHERWISE...THE SUBTROPICAL 500MB RIDGE OVER THE VALLEY EXTENDING
INTO THE GULF OF MEXICO IS KEEPING THINGS HOT AND DRY. RIDGE OVER
THE SOUTHWEST U.S. WILL SHIFT OVER TX THE NEXT FEW DAYS AS THE
TROUGH OVER THE OHIO VALLEY LIFTS OUT OVER THE NORTHEAST U.S.
THEREFORE...HOT AND DRY CONDITIONS WILL CONTINUE WITH TEMPS POSSIBLY
A DEGREE HIGHER TUESDAY AS SUBSIDENCE GRADUALLY INCREASES AHEAD OF
CHANTAL WHEN IT REACHES THE YUCATAN PENINSULA.

EXTENDED...AT THIS TIME IT IS TOO EARLY TO SAY WITH CONFIDENCE WHERE
CHANTAL GOES ONCE IT REACHES THE YUCATAN BUT THE MODELS APPEAR TO BE
MORE CONSISTENT IN BRINGING IN INTO THE WESTERN GULF OF MEXICO
WEDNESDAY. ONCE AGAIN...FLUCTUATIONS IN SPEED AND STRENGTH ARE
MAKING IT DIFFICULT TO SAY WHERE IT WILL GO AFTER THAT.
HOWEVER...LATEST AVN MODEL RUN SEEMS TO BELIEVE THAT THE RIDGE OVER
TEXAS WILL STEER THE SYSTEM WEST NORTHWEST TOWARDS THE LOWER TEXAS
COAST/NORTHEAST MEXICAN TOAST BY FRIDAY AND SEEMS REASONABLE IN
COMPARISON WITH HPC GUIDANCE EVEN THOUGH THERE IS LOW CONFIDENCE IF
ANY IN EITHER SOLUTION. WILL REMAIN CONSERVATIVE ATTM AND CONTINUE
PREVIOUS FRCST FOR CONTINUITY WITH SLIGHT CHANGES TO WIND AND
PRECIP. WILL MENTION THE POTENTIAL FOR RIP CURRENTS AND BEACH
FLOODING FOR THURSDAY AND FRIDAY IN COASTAL ZONES.

MARINE...WILL REMAIN BELOW SCA CRITERIA THOUGH WEDNESDAY. WINDS
SHIFTING TO THE NORTHEAST BY THEN. THURSDAY AND FRIDAY LIKELY TO
REACH SCA CRITERIA AS THE EFFECTS OF CHANTAL REACH THE LOWER TEXAS
COASTAL WATERS. THESE WINDS AND SEAS MAYBE MUCH HIGHER DEPENDING ON
THE STRENGTH AND SPEED OF THE STORM. SHOULD SEE INCREASE IN SQUALLS
BY THURSDAY NIGHT AS CHANTAL MOVES TOWARDS THE NORTHEAST
MEXICAN/LOWER TEXAS GULF COAST. ALL MARINE INTERESTS SHOULD CONTINUE
TO MONITOR THE LATEST ADVISORIES FROM NHC.

BRO UU 077/098 078/099 078 10/00/00/00/00
HRL UU 076/100 077/101 077 10/00/00/00/00
MFE UU 079/101 080/102 080 10/00/00/00/00
RGC UU 080/105 081/106 081 10/00/00/00/00
SPI UU 081/091 082/092 082 10/00/00/00/00

PUBLIC-SYNOPTIC...CASTILLO
AVIATION-MARINE-MESO....GUERRERO

INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO

.BRO...NONE.

TXZ248>257-200100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
654 PM CDT SUN AUG 19 2001

...SEVERE THUNDERSTORMS JUST NORTH OF BROOKS AND JIM HOGG
COUNTIES...

SEVERE THUNDERSTORMS HAVE DEVELOPED THIS EVENING JUST NORTH OF BROOKS
AND JIM HOGG COUNTIES...IN ADJACENT DUVAL COUNTY. THESE TWO SEPARATE
SEVERE THUNDERSTORMS ARE LOCATED 13 MILES NORTH OF HEBBRONVILLE AND 23
MILES NORTHEAST OF HEBBRONVILLE AND THIS AREA OF SEVERE WEATHER HAS BEEN
DRIFTING SLOWLY SOUTH. IF THESE THUNDERSTORMS CONTINUE TO BUILD WEST...
AND DRIFT SOUTH...SEVERE THUNDERSTORM WARNING MAY BE NECESSARY FOR THE
NORTHERN AREAS OF JIM HOGG AND NORTHWEST BROOKS COUNTIES DURING THE
NEXT HOUR.

STAY TUNED TO NOAA WEATHER RADIO FOR ANY ISSUANCE OF SEVERE WEATHER
PRODUCTS...OR MONITOR LOCAL TELEVISION OR RADIO BROADCASTS. PHILO