409
FXUS64 KBRO 151840
AFDBRO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
140 PM CDT MON JUN 15 2026
..NEW DISCUSSION, AVIATION, MARINE
KEY MESSAGES
UPDATED AT 135 PM CDT MON JUN 15 2026
* HEAVY RAIN WITH THE POTENTIAL FOR SIGNIFICANT TO CATASTROPHIC
FLASH FLOODING IS LIKELY FOR DEEP SOUTH TEXAS THE REST OF TODAY
THROUGH WEDNESDAY, WITH RAINFALL RATES BETWEEN 2 TO 5 INCHES AN
HOUR POSSIBLE. A FLOOD WATCH IS IN EFFECT INTO THURSDAY MORNING.
* MOST AREAS SHOULD EXPECT TO RECEIVE BETWEEN 5-10 INCHES OF RAIN
BETWEEN NOW AND THURSDAY MORNING, WITH SOME LOCALIZED AREAS
RECEIVING 12+ INCHES. AVOID UNNECESSARY TRAVEL, AS FLOODING
CONDITIONS CAN ESCALATE QUICKLY.
* THE NATIONAL HURRICANE CENTER HAS INCREASED CHANCES OF
DEVELOPMENT OFF THE TEXAS COAST FROM 30% TO 50% FOR THE NEXT 7
DAYS AS TODAY AND TOMORROW'S CONVECTION MOVES OFFSHORE.
* HEAT RISK CONTINUES THROUGH THE REMAINDER OF THE WEEK. THE WORST
DAY WILL BE THURSDAY, WITH MAJOR (LEVEL 3 OF 4) HEAT RISK EXPECTED
AND HEAT ADVISORIES LIKELY NEEDED. SOME AREAS COULD ALSO REACH
HEAT ADVISORY CRITERIA WEDNESDAY AFTERNOON.
* A MODERATE RISK OF RIP CURRENTS WILL CONTINUE THROUGH TOMORROW.
THIS RISK COULD POTENTIALLY INCREASE THROUGHOUT THE WEEK.
DISCUSSION
ISSUED AT 135 PM CDT MON JUN 15 2026
HEAVY RAIN WITH THE POTENTIAL FOR CATASTROPHIC FLASH FLOODING IS
HIGHLY POSSIBLE IN THE RIO GRANDE VALLEY AND DEEP SOUTH TEXAS OVER
THE NEXT FEW DAYS. AVOID UNNECESSARY TRAVEL TODAY THROUGH WEDNESDAY
IF POSSIBLE, AS ROADWAYS CAN BECOME QUICKLY FLOODED IN AREAS WHERE
HEAVY RAINFALL OCCURS (AS HAS ALREADY BEEN OBSERVED IN PORTIONS OF
THE CENTRAL RIO GRANDE VALLEY THIS MORNING).
THE WEATHER PREDICTION CENTER HAS ALL OF DEEP SOUTH TEXAS UNDER A
MODERATE RISK (LEVEL 3 OF 4) OF EXCESSIVE RAINFALL FOR THE REMAINDER
OF TODAY INTO THIS EVENING, AND KEEPS THE MODERATE RISK FOR THE
EASTERN PORTION OF THE CWA TOMORROW. THE WESTERN PORTION OF THE CWA
IS UNDER A SLIGHT (LEVEL 2 OF 4) RISK OF EXCESSIVE RAINFALL
TOMORROW, AND THE COASTAL COUNTIES REMAIN UNDER A SLIGHT RISK OF
EXCESSIVE RAINFALL ON WEDNESDAY. RAINFALL RATES OF ANYWHERE BETWEEN
2 TO 5 INCHES PER HOUR ARE POSSIBLE WITH THESE SHOWERS AND
THUNDERSTORMS, AND WE ARE LIKELY TO SEE AREAS OF TRAINING CONVECTION
(IE, THE SAME AREAS RECEIVING MULTIPLE ROUNDS OF HEAVY RAIN) DUE TO
THE OVERRUNNING NATURE OF THE CONVECTIVE SETUP.
A VERY SLOW-MOVING COLD FRONT REMAINS DRAPED OVER CENTRAL TEXAS THIS
AFTERNOON, AND THE AIR REMAINS RICHLY SATURATED WITH VERY HIGH PWATS
EXPECTED (OVER 2.5 INCHES IN SOME AREAS), DUE TO A COMBINATION OF
UPPER LEVEL TROPICAL MOISTURE FROM PACIFIC STORM REMNANTS AND RICH
SURFACE MOISTURE BEING ADVECTED FROM A WARM GULF. IN ADDITION,
THERE IS THE PRESENCE OF A MID TO UPPER LEVEL LOW THAT IS EXPECTED
TO MOVE DIRECTLY ACROSS THE AREA OVER THE NEXT FEW DAYS ALONG WITH A
SURFACE TROUGH, WHICH WILL ADD TO THE INSTABILITY AND THE RAIN
POTENTIAL. SOUTHERLY SURFACE FLOW IS EXPECTED TO OVERRUN THE FRONT
AND SURFACE TROUGH, WHICH SHOULD CREATE AREAS OF WIDESPREAD TRAINING
RAINFALL OVER DEEP SOUTH TEXAS OVER THE NEXT FEW DAYS.
RAIN CHANCES WILL REMAIN HIGH TO VERY HIGH (80 TO 100%) THROUGH
TOMORROW EVENING BEFORE THE THREAT BEGINS TO SLOWLY MOVE OFFSHORE.
RAIN CHANCES WILL DECREASE TO LOW TO MODERATE (30-60%) TOMORROW
NIGHT INTO WEDNESDAY BUT THE FLOODING POTENTIAL WILL STILL PERSIST
DUE TO OVER-SATURATED SOIL. A FLOOD WATCH REMAINS IN EFFECT INTO
THURSDAY MORNING.
THE MOST LIKELY RAINFALL AMOUNTS BETWEEN NOW AND THURSDAY MORNING
WILL BE BETWEEN 5 TO 10 INCHES, WITH SOME ISOLATED AREAS RECEIVING
UP TO 12 INCHES. THERE IS ONGOING CONVECTION WHICH HAS ALREADY
CAUSED FLOODING ISSUES IN THE MIDDLE RIO GRANDE VALLEY, WITH SOME
AREAS NEAR WESLACO AND PROGRESO ALREADY RECEIVING UP TO 4 TO 6
INCHES THIS MORNING. HEAVIER CONVECTION IS EXPECTED TO DEVELOP LATER
THIS EVENING IN THE WESTERN RANCHLAND COUNTIES AND SLOWLY SPREAD
EASTWARD OVERNIGHT INTO TOMORROW AND TOMORROW EVENING. AREAS THAT
ALREADY RECEIVED RAINFALL TODAY WILL BE PARTICULARLY PRONE TO FLASH
FLOODING, AS THE GROUND IS ALREADY HIGHLY SATURATED (WITH SOME AREAS
STILL HAVING STANDING WATER) IN THESE AREAS DUE TO THIS MORNING'S
CONVECTION.
THE NATIONAL HURRICANE CENTER HAS ALSO INCREASED THE CHANCES OF
TROPICAL DEVELOPMENT JUST OFF THE TEXAS COAST FROM 30% TO 50% FOR
THE NEXT 7 DAYS. CONFIDENCE IS INCREASING THAT INLAND CONVECTION
THAT MOVES OFFSHORE OVER THE NEXT FEW DAYS COULD BRIEFLY DEVELOP
INTO A TROPICAL SYSTEM AS AN INLAND TROUGH MOVES OFFSHORE. THERE IS
A 40% CHANCE OF FORMATION IN THE NEXT 48 HOURS, AND A 50% CHANCE OF
FORMATION OVER THE NEXT 7 DAYS. IF THIS CHANCE MATERIALIZES, WE
COULD SEE POTENTIAL DEVELOPMENT OFFSHORE AS SOON AS WEDNESDAY INTO
THURSDAY, MOST LIKELY IMPACTING AREAS TO OUR NORTH AND EAST, BUT
EXACT IMPACTS AND LOCATIONS ARE STILL UNKNOWN AT THIS TIME. THIS
WILL CONTINUE TO BE MONITORED.
HEAT RISK WILL BE A LITTLE LESS PRONOUCED DURING ONGOING CONVECTION
TOMORROW, THOUGH STILL A BIT OF A CONCERN. HOWEVER, MAJOR HEAT RISK
(LEVEL 3 OF 4) WILL BE POSSIBLE ON THURSDAY AS THE RAIN BEGINS TO
MOVE EASTWARD AND SKIES BECOME MORE SUNNY. SOME AREAS COULD REACH
HEAT ADVISORY CRITERIA AS SOON AS WEDNESDAY AFTERNOON (WHICH WILL
MOSTLY BE MODERATE, WITH SOME SMALL POCKETS OF MAJOR HEAT RISK).
THIS HEAT RISK CONCERN CONTINUES THROUGH THE WEEKEND, THOUGH
THURSDAY APPEARS THE BE THE MOST IMPACTFUL DAY.
A MODERATE RISK OF LIFE-THREATENING RIP CURRENTS IS ALSO EXPECTED AT
AREA BEACHES THROUGH TOMORROW. THIS COULD INCREASE LATER THIS WEEK,
ALONG WITH BEACH HAZARDS DEPENDING HOW INLAND CONVECTION BEHAVES
ONCE IT MOVES OVER THE GULF.
AVIATION
(18Z TAFS)
ISSUED AT 135 PM CDT MON JUN 15 2026
CONDITIONS ARE EXPECTED TO DETERIORATE THROUGHOUT THE DAY AS SPOTTY
SHOWER AND STORM DEVELOPMENT CONTINUES. INTERMITTENT VFR TO MVFR
CEILINGS ARE EXPECTED THROUGHOUT THE AFTERNOON AND EARLY EVENING
BEFORE CEILINGS SHOULD STAY MVFR BY 02-03Z AND DECREASE TO IFR
OVERNIGHT BETWEEN 09-12Z. WINDS SHOULD BE LIGHT TO MODERATE AND
SOUTHEASTERLY THROUGH THE ENTIRE TAF PERIOD WITH SHOWERS GIVING WAY
TO HEAVIER RAIN BY TOMORROW MORNING.
MARINE
ISSUED AT 135 PM CDT MON JUN 15 2026
CONDITIONS WILL BECOME INCREASINGLY ADVERSE TONIGHT INTO TOMORROW AS
LOW PRESURE MOVES OVER THE AREA. SMALL CRAFT ADVISORIES COULD BE
NEEDED TOMORROW AFTERNOON, AND COULD BE ALSO NEEDED INTERMITTENTLY
THROUGH FRIDAY AS THE TROUGH MOVES OFFSHORE, INCREASING THE PRESSURE
GRADIENT AND WAVE HEIGHTS. CONDITIONS COULD SLIGHTLY IMPROVE FOR
THE WEEKEND, BUT SMALL CRAFT EXERCISE CAUTION MAY STILL BE NEEDED
THROUGH THE WEEKEND.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 79 85 77 92 / 70 90 60 40
HARLINGEN 76 83 74 92 / 80 90 60 30
MCALLEN 77 83 77 94 / 100 90 40 20
RIO GRANDE CITY 75 84 74 94 / 90 90 30 10
SOUTH PADRE ISLAND 81 85 80 89 / 70 80 70 40
BAYVIEW/PORT ISABEL 78 85 76 92 / 70 90 70 40
BRO WATCHES/WARNINGS/ADVISORIES
TX...FLOOD WATCH THROUGH THURSDAY MORNING FOR TXZ248>255-351-353>355-
451-454-455.
GM...NONE.
SHORT TERM...55-MM
LONG TERM....55-MM
AVIATION...55-MM
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