Severe Thunderstorm Warning 12, NWS Brownsville, TX

DEEP SOUTH TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1100 PM CDT SUN MAY 6 2001

HAVE ALREADY UPDATED THE ZONES EARLIER THIS EVENING PER THE PREVIOUS
DISCUSSION.  IN ADDITION TO THE ACTIVITY TO THE NORTH OF THE COUNTY
WARNING AND FORECAST AREA...THUNDERSTORMS AND ASSOCIATED AREAS OF
HEAVIER RAIN ARE NOW DEVELOPING TO THE WEST OF THE RIO GRANDE IN
NORTHEAST MEXICO.  RAINFALL OVER ZAPATA COUNTY HAS BECOME MORE
WIDESPREAD AND A BIT HEAVIER THE LAST HOUR OR TWO.  WILL CONTINUE TO
TRACK THROUGH THE NIGHT.

AT THE MOMENT THERE IS LITTLE IF ANY CAP IN THE ATMOSPHERE...AND
WITH HIGH DEWPOINTS THERE WILL BE LITTLE CHANCE FOR ONE TO DEVELOP
OVERNIGHT.  THUS...MONDAY HOLDS THE POTENTIAL FOR CONTINUED
CONVECTIVE ACTIVITY FOR DEEP SOUTH TEXAS.  A WEAK COOL FRONT WILL
ATTEMPT TO PUSH TOWARD DEEP SOUTH TEXAS ON TUESDAY...WHICH COULD
TRIGGER ADDITIONAL SHOWERS THEN...BUT UPPER RIDGING WILL TAKE OVER
BY MID WEEK...INHIBITING FURTHER CONVECTION.

MARINE...MODERATE SOUTHEAST WINDS SHOULD CONTINUE OVERNIGHT...WITH
WINDS AND SEAS BELOW ADVISORY CRITERIA.  REMOVED THE EXERCISE
CAUTION WORDING FOR NOW SINCE SEAS WERE STEADY AT 5 FEET AT BUOY020.

AVIATION-MARINE
(LEAD)...TS.60/PUBLIC-SYNOPTIC...BHM.54/MESO...MARTINEZ

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

.BRO...NONE.

TXZ248>257-071400-

DEEP SOUTH TEXAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BROWNSVILLE TX
900 PM CDT SUN MAY 6 2001

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN
PORTIONS OF DEEP SOUTH TEXAS TONIGHT.  THE SLIGHT RISK AREA IS
IN THE NORTHERN PARTS OF KENEDY...BROOKS...JIM HOGG...AND ZAPATA
COUNTIES.  THE REMAINDER OF DEEP SOUTH TEXAS REMAINS UNDER A GENERAL
THUNDERSTORM OUTLOOK AREA FOR TONIGHT.

THIS EVENING AN UPPER LEVEL DISTURBANCE WAS LOCATED OVER OKLAHOMA.
THE DISTURBANCE WAS TRIGGERING THUNDERSTORMS ALONG A LINE EXTENDING
SOUTHWEST ACROSS CENTRAL TEXAS AND INTO SOUTH TEXAS.  THE
THUNDERSTORMS ALONG THE CONVECTIVE LINE WERE BEING TRIGGERED IN A
MOISTURE RICH ENVIRONMENT AND SOME HAVE ALREADY BECOME SEVERE.
EXPECT CONVECTION TO CONTINUE MOVING SOUTHEAST INTO AND THROUGH DEEP
SOUTH TEXAS OVERNIGHT...APPROACHING COASTAL AREAS BY EARLY MORNING.

LARGE HAIL AND STRONG STRAIGHT LINE WINDS ARE EXPECTED TO BE THE
MAIN SEVERE WEATHER THREATS...HOWEVER...ISOLATED TORNADOES CAN NOT
BE RULED OUT.

SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL IN THE SLIGHT RISK
AREA SHOULD MONITOR WEATHER DEVELOPMENTS AND BE READY FOR POSSIBLE
ACTIVATION.

...TECHNICAL INFORMATION...

A WELL DEFINED SHORTWAVE TROUGH AXIS...TRAILING SOUTHWARD FROM A
VORT MAX NOW OVER SOUTHEASTERN COLORADO AND THE OKLAHOMA
PANHANDLE...WILL CONTINUE SHIFTING EAST ACROSS 	MUCH OF CENTRAL AND
EAST TEXAS OVERNIGHT. VERY LARGE SURFACE BASED CAPES AND STEEP MID
LEVEL LAPSE RATES WILL CONTIBUTE TO AN ENVIRONMENT PRIMED FOR
FURTHER CONVECTION.

SPEECE/MILLER