Severe Thunderstorm Warning 66, NWS Brownsville, TX

DEEP SOUTH TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
320 PM CDT THU AUG 30 2001

CURRENT KBRO REFLECTIVITY DATA IS SHOWING THE GREATEST CONCENTRATION
OF CONVECTIVE ACTIVITY THIS AFTERNOON OVER THE NORTHERN BAND OF
COUNTIES IN OUR CWA.  AS WAS THE CASE YESTERDAY...THE ACTIVITY IS
REMAINING BELOW SEVERE LIMITS...PROBABLY DUE TO LITTLE INSOLATION SO
FAR TODAY.  WATER VAPOR IMAGERY CONTINUES TO SHOW A MOIST ATMOSPHERE
OVER ALL OF TEXAS AND MOST OF MEXICO...WITH A MID-LEVEL VORT MAX
NOTED NEAR THE BIG BEND REGION.  A VERY WEAK AND ERRATIC MID/UPPER
FLOW PATTERN WILL REMAIN OVER DEEP SOUTH TEXAS THROUGH THIS
WEEKEND...WITH A GENERAL 500 MB TROUGH IN PLACE OVER TEXAS.
MID-LEVEL RIDGING ATTEMPTS TO BUILD BACK OVER SOUTH TEXAS FROM BOTH
THE EAST AND THE WEST...BUT GEOPOTENTIAL HEIGHTS DO NOT FLUCTUATE BY
MORE THAN A COUPLE OF DECAMETERS THROUGHOUT THE PERIOD.  WITH
GENERAL MID-LEVEL TROFFING OVER THE AREA...PRECIPITABLE WATER VALUES
EXPECTED TO REMAIN AROUND 2 INCHES...AND SEVERAL VORT MAXES
FORECASTED TO PASS THROUGH THE MEAN TROUGH POSITION...WILL KEEP
LOW-END SCATTERED POPS IN THE FORECAST REGION-WIDE THROUGH SATURDAY
NIGHT.  THINK THAT MAV NUMERICAL GUIDANCE IS MORE REALISTIC THAN THE
HIGHER FWC NUMBERS...BUT LOW-END SCATTERED POPS WILL SERVE AS A GOOD
COMPROMISE.

FOR THE EXTENDED PERIODS...WILL KEEP CHANCE POPS IN THE FORECAST
THROUGH TUESDAY AND GO WITH A PARTLY CLOUDY AND DRY FORECAST ON
WEDNESDAY AND THURSDAY.  THIS DECISION IS BASED ON LONG RANGE
GUIDANCE...WHICH KEEPS 500 MB TROUGH OVER THE AREA THROUGH TUESDAY
BEFORE MORE SUBSTANTIAL RIDGING BUILDS BACK OVER THE AREA FROM THE
CENTRAL GULF COAST REGION.

MARINE...BUOY 020 INDICATES SOUTHEAST WINDS AT 10-15 KNOTS AND 5-6
FOOT SEAS OFFSHORE THIS AFTERNOON.  SCEC STATEMENTS WILL BE
NECESSARY FOR THE OFFSHORE WATERS OVERNIGHT...AND MAY BE NEEDED IN
ALL MARINE AREAS AGAIN TOMORROW.  SHOWERS AND THUNDERSTORMS CAN BE
EXPECTED THROUGH THE BEGINNING OF NEXT WEEK.

PRELIMINARY NUMBERS:
BRO BB 078/094 078/094 078  30/30/30/30/30
HRL BB 077/094 077/094 077  30/30/30/30/30
MFE BB 078/095 078/095 078  30/30/30/30/30
RGC BB 076/097 076/097 076  30/30/30/30/30
SPI BB 078/088 078/088 078  30/30/30/30/30

SYNOPTIC...DD (65) / AVIATION-MARINE-MESO...PY (69)

.BRO...NONE.

TXZ252-253-255-310225-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
815 PM CDT THU AUG 30 2001

...STRONG THUNDERSTORMS DEVELOPING OVER STARR AND JIM HOGG COUNTIES...

AT 815 PM...BROWNSVILLE DOPPLER RADAR INDICATED AN AREA OF STRONG
THUNDERSTORMS OVER WESTERN AND NORTHERN STARR...SOUTHERN AND CENTRAL
JIM HOGG...AND EXTREME EASTERN ZAPATA COUNTY. THE STORMS ARE MOVING
TO THE NORTH AT 20 MPH.

THESE STORMS WILL LIKELY PRODUCE HAIL...BRIEF STRONG GUSTY WINDS TO
40 MPH...AND VERY HEAVY RAINS...AS THEY AFFECT SPARSELY POPULATED AREAS
OF THE WESTERN VALLEY. IF THE STORMS HOLD TOGETHER...THEY WILL BE
REACHING THE HEBBRONVILLE VICINITY IN NORTHERN JIM HOGG COUNTY
BY 845 PM.

ADDITIONAL THUNDERSTORMS ARE MOVING INTO SOUTHWEST HIDALGO COUNTY...
ALTHOUGH THESE HAVE DIMINISHED IN INTENSITY SOMEWHAT AFTER CROSSING
THE RIO GRANDE FROM MEXICO.

STAY TUNED TO NOAA WEATHER RADIO AND THE NATIONAL WEATHER SERVICE IN
BROWNSVILLE FOR FURTHER UPDATES.

NEWMAN