Severe Thunderstorm Warning 24, NWS Brownsville, TX

DEEP SOUTH TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
325 PM CDT THU JUL 4 2002

SHORT TERM...THE 12Z BRO SOUNDING SHOWS AN REVERSAL IN THE OVERALL
DRYING TREND THAT HAS PREVAILED OVER THE LAST COUPLE OF DAYS
REPORTING AN INCREASED PWAT NEAR 1.68 INCHES AND AN LI OF -9.9.  THE
DESTABILIZATION AND INCREASE IN MOISTURE HAS OCCURRED DUE TO THE
CONTINUED PRESENCE OF THE NEARLY STATIONARY 5H TROUGHING OVER THE
REGION.  THE LATEST MESO-ETA RUNS INDICATE THAT THE 5H TROUGH HAS
SPLIT INTO TWO PORTIONS...THE FIRST CENTERED OVER CENTRAL AND
WESTERN TX AND A SECOND CENTERED OVER EASTERN AND SOUTHERN MEXICO.
THIS UPPER LEVEL CONFIGURATION HAS RESULTED IN A SERIES OF VORT
MAXES EXTENDING FROM SOUTH CENTRAL TX SOUTHWARDS ACROSS THE WESTERN
PORTIONS OF DEEP SOUTH TX TO JUST WEST OF TAMPICO.  THE TROUGHING
AND VORT MAXES REMAIN QUASI-STATIONARY IN THE SHORT TERM DUE TO THE
FEATURES BEING BRACKETED TO THE SOUTHWEST AND NORTHEAST BY STRONG 5H
RIDGES OVER THE CENTRAL MISS RIVER VALLEY AND THE BAJA CA REGION.
MODEL TRENDS INDICATE THAT RIDGES EVENTUALLY MERGE RESULTING IN A
LARGE DOMINANT RIDGE OVER THE LOWER 48 STATES AROUND AND AFTER 60
HRS DISSIPATING THE TROUGH.  WITH THE RESULTING INCREASING
SUBSIDENCE AND DRYING OF THE ATMS...RAIN CHCS WILL GRADUALLY SHIFT
WEST AND DIMINISH.

THE INCREASING RIDGING THROUGH 60 HRS WILL FORCE AFTERNOON HIGH
TEMPS A LITTLE HIGHER OVER THE NEXT SEVERAL DAYS AS MORE ABUNDANT
SUNSHINE PREVAILS.

THIS TREND IS REFLECTED PRETTY WELL IN THE CURRENT ZFP.  HOWEVER...
WILL INCREASE PCPN CHCS IN THE SHORT TERM...MAINLY OVER THE CENTRAL
AND WESTERN ZFP.

THE DISSIPATION OF THE 5H TROUGH WILL ALSO RESULT IN LESS OF A PGF
OVER THE NEXT SEVERAL DAYS ALLOWING FOR A LESS BREEZY SE SURFACE
FLOW.

EXTENDED...THE 5H RIDGING REMAINS ENTRENCHED OVER MOST OF THE LOWER
48 STATES IN THE EXTENDED RANGE PERIOD.  HOWEVER...OVER THE EAST
COAST...A 5H TROUGH NOW SITUATED OVER THE SE U.S. PIVOTS AROUND THE
EAST AND SOUTHERN SIDE OF 5H RIDGE AND TRACKS WESTWARD ACROSS THE
GULF OF MEX DURING THE SUN-TUES PERIOD.  THE MRF/ECMWF AND UKMET ALL
AGREE IN THIS GENERAL TREND...ALTHOUGH THE ECMWF IS FASTER AND
FURTHER SOUTH WITH THE TRACK OF THIS SYSTEM THAN THE MRF.  THE AVN
IS ALSO SHOWS A MORE SOUTHERLY TRACK WITH A WEAKER 5H SYSTEM.  WITH
OVERALL MODEL TRENDS IN REASONABLE AGREEMENT...THERE APPEARS ENOUGH
JUSTIFICATION TO MAINTAIN A MENTION OF POPS FOR EARLY NEXT WEEK.
TEMPS WILL REMAIN AT OR ABOVE CLIMO FOR THIS PERIOD.

MARINE...AT 1 PM BUOY020 REPORTED SOUTHEAST WINDS 17-21 KNOTS WITH
SEAS OF 6 FEET AT 7 SECONDS. AT 2 PM BUOY002 REPORTED ESE WINDS
16-19 KNOTS WITH SEAS 5 FT AT 7 SEC. WITH H5 TROUGH LIFTING TO THE
NW OVERNIGHT...SPGF SHOULD CONTINUE TO RELAX WITH CONCOMITANT DROP
IN WINDS AND SEAS..AS RIDGE AND TROUGH WEAKEN FRI/SAT. SCA FOR BAY
WILL BE ALLOWED TO EXPIRE...BUT WILL KEEP SCA FOR OFFSHORE DUE TO
SEAS. EXPECT SEAS TO DROP BELOW SCA CRITERION OVERNIGHT. A WEAK
EASTERLY WAVE IS FORECAST TO MOVE ACROSS THE NORTHERN GULF OF MEXICO
CAUSING FLUCTUATIONS IN WIND DIRECTION OVER THE DPSOTEX COASTAL
WATERS SUN/MON AND BRINGING ANOTHER CHANCE FOR SHOWERS BY MONDAY.
S/SE FLOW SHOULD RESUME MON NIGHT...AS SFC WAVE MOVES INLAND OVER
DPSOTEX/NE MEX AND SFC TROUGH MOVES INTO NRN TX.

TROPICS...SURFACE ANALYSIS INDICATES THE PRESENCE OF 3 TROPICAL
WAVES OF CONCERN IN THE ATLANTIC/CARIB/GULF REGION.  THE FIRST
LOCATED OVER CENTRAL AMERICA AND SOUTHERN MEXICO APPEARS BOUND FOR
THE E PAC.  THE 2ND IS LOCATED OVER THE CENTRAL CARIB WITH THE 3RD
LOCATED OVER THE CENTRAL TROPICAL ATLANTIC.  ALL OF THESE WAVES ARE
MOVING WEST AT 10 TO 20 KTS WITH LITTLE OR NO ASSOCIATED DEEP CONV.
ACCORDINGLY...THE LATEST TWO FROM TPC INDICATES NO TROPICAL CYCLONE
DEVELOPMENT THROUGH FRI.

BRO BB 079/093 079/094 078 20/20/00/00/00
HRL BB 078/095 078/096 078 30/30/00/00/00
MFE BB 076/097 076/098 076 30/30/20/00/00
RGC BB 077/099 076/100 076 30/30/20/00/00
SPI BB 080/088 080/089 079 20/20/00/00/00

SYNOPTIC...60/AVIATION-MARINE-MESO...59

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

.BRO...SMALL CRAFT ADVISORY TONIGHT GMZ150-155-170-175.

TXZ248>257-050700-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BROWNSVILLE TX
555 PM CDT THU JUL 4 2002

...HAZARDOUS WEATHER OUTLOOK FOR DEEP SOUTH TEXAS...

THROUGH THE EVENING HOURS...SCATTERED SHOWERS AND THUNDERSTORMS
WILL PERSIST OVER THE WESTERN PORTIONS OF DEEP SOUTH TEXAS AS AN
UPPER LEVEL TROUGH OF LOW PRESSURE REMAINS NEARLY STATIONARY OVER
TEXAS. ALTHOUGH NO WIDESPREAD SEVERE WEATHER IS EXPECTED THIS
AFTERNOON...THE EVENING THUNDERSTORMS WILL PRODUCE FREQUENT
LIGHTNING...LOCALLY HEAVY RAINS AND BRIEF WIND GUSTS FROM 25 TO
35 MPH.

THE MAJORITY OF THE SHOWERS AND THUNDERSTORM ACTIVITY WILL OCCUR
OVER ZAPATA...JIM HOGG...STARR...BROOKS AND HIDALGO COUNTIES THIS
EVENING.

STAY TUNED TO NOAA WEATHER RADIO FOR THE LATEST WEATHER INFORMATION
FOR DEEP SOUTH TEXAS.

FOR THE LATEST WEATHER FORECASTS AND SEVERE WEATHER INFORMATION FOR
DEEP SOUTH TEXAS...VISIT OUR WEB SITE AT HTTP://WWW.SRH.NOAA.GOV/BRO.

TEXAS ROAD CLOSURE INFORMATION CAN BE FOUND TOLL-FREE AT
1-800-452-9292 OR AT THE FOLLOWING WEB SITE...
HTTP://WWW.DOT.STATE.TX.US/HCR/MAIN.HTM

SPEECE