651
FXUS64 KBRO 201730
AFDBRO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1230 PM CDT WED AUG 20 2025
..NEW DISCUSSION, AVIATION, MARINE
DISCUSSION
ISSUED AT 1230 PM CDT WED AUG 20 2025
DEEP SOUTH TEXAS WILL REMAIN IN AN UNSETTLED WEATHER PATTERN
THROUGH AT LEAST EARLY NEXT WEEK AS SUBSIDENCE ASSOCIATED WITH THE
MID LEVEL RIDGE OVER THE FOUR CORNERS LESSENS AND WEAK TROUGHING
SETS UP ACROSS THE SOUTHERN HALF OF TEXAS. WEAK FORCING FOR
ASCENT, FAVORABLE MOISTURE CONTENT, AND DIURNAL INSTABILITY WILL
BE SUFFICIENT ENOUGH TO DEVELOP ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS EACH DAY THROUGH AT LEAST MONDAY. MESOSCALE FEATURES,
SUCH AS THE SEA BREEZE AND REMNANT OUTFLOW BOUNDARIES FROM EARLIER
CONVECTION, WILL ALSO CONTRIBUTE TO THE ISOLATED TO SCATTERED
NATURE OF SHOWERS AND THUNDERSTORMS EACH DAY. BY THE END OF THE
WEEK AND INTO EARLY NEXT WEEK, RAIN CHANCES INCREASE, RANGING FROM
40-60%, AS A SHORTWAVE TRANSLATES ALONG THE PERIPHERY OF THE
AFOREMENTIONED MID LEVEL RIDGE TOWARDS DEEP SOUTH TEXAS AND
PRECIPITABLE WATER VALUES INCREASE AROUND OR JUST ABOVE 2-2.10
INCHES.
THE PEAK TIMING EACH DAY WILL COINCIDE WITH DAYTIME HEATING - EARLY
AFTERNOON THROUGH EARLY EVENING - ALTHOUGH MORNING ACTIVITY
CANNOT BE RULED OUT DURING THE MORNING HOURS DUE TO THE UNSETTLED
WEATHER PATTERN IN PLACE. THE MAIN THREATS WITH ANY ROBUST SHOWERS
OR STRONG THUNDERSTORMS ARE LOCALLY HEAVY RAINFALL, GUSTY WINDS,
AND LIGHTNING. HIGH MOISTURE CONTENT WILL AID IN EFFICIENT HEAVY
RAIN PROCESSES, AND A QUICK 0.5” TO 1” OF RAINFALL CANNOT BE RULED
OUT WITH ANY ACTIVITY EACH DAY. THERE IS A MARGINAL RISK (LEVEL 1
OF 4) OF EXCESSIVE RAINFALL FOR THE NORTHERN PORTIONS OF ZAPATA,
JIM HOGG, AND BROOKS COUNTIES ON THURSDAY AS SOME LOCALLY HEAVY
RAIN MAY RESULT IN MINOR FLASH FLOODING ISSUES. GUSTY WINDS
RANGING FROM 30-40 MPH ARE LIKELY AS WELL WITH ANY ACTIVITY, BUT
ISOLATED WIND GUSTS RANGING FROM 50-55 MPH CANNOT BE RULED OUT
WITH ANY STRONGER THUNDERSTORMS.
INCREASED CLOUD COVER MAY HELP KEEP TEMPERATURES SLIGHTLY BELOW
NORMAL DURING THE AFTERNOON HOURS ACROSS PORTIONS OF THE REGION.
HOWEVER, FOR THOSE AREAS THAT REMAIN RAIN-FREE, EXPECT TEMPERATURES
IN THE MID TO UPPER 90S TO AROUND 100 DEGREES THROUGH FRIDAY, AND
IN THE LOW TO MID 90S THROUGH THE WEEKEND.
AVIATION
(18Z TAFS)
ISSUED AT 1230 PM CDT WED AUG 20 2025
VFR WITH LIGHT WINDS WILL PREVAIL THROUGH THE FORECAST PERIOD.
HOWEVER, ISOLATED TO SCATTERED CONVECTION WILL DEVELOP THIS
AFTERNOON INTO THE EVENING HOURS AND ONCE AGAIN BY MID TO LATE
MORNING TOMORROW DUE TO THE COMBINATION OF FAVORABLE MOISTURE
CONTENT, DIURNAL INSTABILITY, AND WEAK FORCING FOR ASCENT. THE
MAIN THREATS WITH ANY ACTIVITY WILL BE LOCALLY HEAVY RAINFALL,
WIND GUSTS RANGING FROM 30-50 MPH, AND LIGHTNING. MOST ACTIVITY
WILL DISSIPATE WITH THE LOSS OF DAYTIME HEATING, RESULTING IN
MOSTLY RAIN-FREE CONDITIONS TONIGHT.
MARINE
ISSUED AT 1230 PM CDT WED AUG 20 2025
GENERALLY FAVORABLE MARINE CONDITIONS WILL PREVAIL WITH LOW TO
MODERATE SEAS AND LIGHT WINDS. HOWEVER, LOCALLY ENHANCED WINDS AND
SEAS WILL BE POSSIBLE WITHIN ANY SHOWERS OR THUNDERSTORMS THAT
DEVELOP OVER THE GULF WATERS EACH DAY. EXPECT DAILY LOW TO MEDIUM
(20-50%) PRECIPITATION CHANCES THROUGH THE WEEKEND.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 94 78 96 78 / 50 10 10 10
HARLINGEN 95 73 97 73 / 40 10 10 10
MCALLEN 98 77 101 78 / 40 10 20 10
RIO GRANDE CITY 98 76 102 78 / 40 20 20 20
SOUTH PADRE ISLAND 88 80 89 80 / 30 0 10 10
BAYVIEW/PORT ISABEL 91 77 92 77 / 30 0 10 10
BRO WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...NONE.
SHORT TERM...22-GARCIA
LONG TERM....22-GARCIA
AVIATION...22-GARCIA
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