471
FXUS64 KBRO 061052 AAB
AFDBRO
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
552 AM CDT WED MAY 6 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 547 AM CDT WED MAY 6 2026
KEY MESSAGES:
* ELEVATED RELATIVE HUMIDITY AND A SPIKE IN TEMPERATURES RESULT
IN A MAJOR HEAT RISK (LEVEL 3 OF 4) WEDNESDAY AFTERNOON AS
HEAT INDICES ("REAL FEEL" TEMPERATURES) SOAR TO 105-110+ F
ACROSS THE REGION.
* A HEAT ADVISORY IS IN EFFECT FROM 1 PM TO 7 PM WEDNESDAY FOR
SOUTHERN HIDALGO AND INLAND PORTIONS OF CAMERON, WILLACY AND
KENEDY COUNTIES, WHERE INDICES ARE LIKELY TO EXCEED 111 F FOR
SEVERAL HOURS, POTENTIALLY BRIEFLY REACHING AS HIGH AS 116 F.
* A MEDIUM RISK OF RIP CURRENTS CONTINUES THROUGH WEDNESDAY
AFTERNOON.
* COLD FRONT LIKELY MOVES THROUGH THURSDAY AFTERNOON OR THURSDAY
EVENING, INCREASING CHANCES OF RAIN FROM DEVELOPING SHOWERS AND
THUNDERSTORMS TO AS MUCH AS A MEDIUM TO LIKELY (50-80%) CHANCE
THURSDAY NIGHT, FOLLOWED BY A LOW TO MEDIUM (30-60%) CHANCE ON
FRIDAY.
* UNCERTAINTY REMAINS HIGH AND PROBABILITIES ARE LOW AND
CONDITIONAL, BUT THERE IS A GRADUALLY INCREASING SIGNAL FOR
STRONG TO SEVERE THUNDERSTORMS LATE THURSDAY AFTERNOON OR
EVENING, WITH HAIL AND STRONG WINDS POSSIBLE.
DISCUSSION
ISSUED AT 1040 PM CDT TUE MAY 5 2026
ANOTHER DAY OF BRUTAL TEMPERATURES AND HEAT INDICES IS ON TAP FOR
DEEP SOUTH TEXAS ON WEDNESDAY AS A TROUGH MOVING INTO NORTHERN
MEXICO PUSHES A MID/UPPER LEVEL HIGH PRESSURE EASTWARD INTO THE
CENTRAL GULF BY THURSDAY, MINIMIZING CLOUD COVER WHILE SOUTHEASTERLY
FLOW, GUSTING TO 20-30 MPH FURTHER EAST, ADVECTS IN HIGHER MOISTURE
CONTENT. ADDITIONALLY, A DRYLINE MOVING INTO AT LEAST THE WESTERN
PORTIONS OF OUR REGION IN THE AFTERNOON BRINGS IN DOWNSLOPE
COMPRESSIONAL HEATING, FURTHER SPIKING TEMPERATURES TO AS HIGH AS
THE LOWER 100S ALONG/WEST OF US-281 AND UPPER 90S ELSEWHERE.
FACTORING IN ELEVATED RELATIVE HUMIDITY, A MAJOR HEAT RISK IS
EXPECTED AS HEAT INDICES REACH 105-110+ F ACROSS MOST OF THE CWA. A
HEAT ADVISORY IS IN EFFECT FROM 1 PM TO 7 PM WEDNESDAY FOR SOUTHERN
HIDALGO AND INLAND PORTIONS OF CAMERON, WILLACY AND KENEDY COUNTIES,
WHERE INDICES GREATER THAN 111 F ARE EXPECTED TO LAST FOR SEVERAL
HOURS, POTENTIALLY BRIEFLY TOPPING OUT AT 116 F. THIS TYPE OF HEAT
PUTS EVERYONE AT RISK FOR HEAT-RELATED ILLNESSES, PARTICULARLY FOR
THOSE WITHOUT EFFECTIVE COOLING OR HYDRATION. THUS, WE RECOMMEND
DRINKING PLENTY OF WATER AND AVOIDING STRENUOUS ACTIVITIES DURING
THE AFTERNOON AND EARLY EVENING HOURS. DRIER AIR MOVING IN BEHIND
THE DRYLINE SHOULD KEEP APPARENT TEMPERATURES A BIT LOWER ACROSS THE
RIO GRANDE PLAINS, MOST OF THE UPPER RGV AS WELL AS WESTERN PORTIONS
OF THE NORTHERN RANCHLANDS. HOWEVER, A SPS MAY BE ISSUED OVERNIGHT
OR WEDNESDAY MORNING FOR THESE AREAS AS WELL, WHERE INDICES COULD
STILL REACH 111 F OR HIGHER FOR AN HOUR OR TWO.
THE TROUGH MOVES NORTH OF DEEP SOUTH TEXAS WEDNESDAY NIGHT INTO
THURSDAY MORNING AND A BUILDING SURFACE HIGH PRESSURE OVER THE
SOUTHERN PLAINS PUSHES A COLD FRONT INTO DEEP SOUTH TEXAS THURSDAY
AFTERNOON OR THURSDAY EVENING. OVERALL, THE LATEST EXPECTATIONS OF
THE FRONT IS FOR IT TO SLOW ITS SOUTHWARD MOVEMENT ACROSS THE REGION
WHILE ALSO DEVELOPING SHOWERS AND THUNDERSTORMS, GRADUALLY
INCREASING CHANCES OF RAIN FROM NORTH TO SOUTH THURSDAY AFTERNOON TO
AS MUCH AS A MEDIUM TO LIKELY (50-80%) CHANCE THURSDAY NIGHT.
INCREASING CLOUD COVERAGE THROUGHOUT THURSDAY SHOULD KEEP HIGH
TEMPERATURES IN THE 80S/90S, THOUGH 100-105 F HEAT INDICES ACROSS
MOST OF THE RGV LIKELY RESULT IN A MODERATE HEAT RISK (LEVEL 2 OF 4).
AS DISCUSSED PREVIOUSLY, ALTHOUGH UNCERTAINTY REMAINS HIGH AND
PROBABILITIES REMAIN LOW, THERE IS A GRADUALLY STRENGTHENING SIGNAL
FOR A CONDITIONAL RISK OF STRONG TO SEVERE CONVECTION PERHAPS AS
EARLY AS LATE THURSDAY AFTERNOON OR THURSDAY EVENING, WITH
CONVECTION BEGINNING OVER THE NORTHWESTERN AREAS (RIO GRANDE
PLAINS AND THE NORTHERN RANCHLANDS) AND MOVING SOUTHEASTWARD INTO
THE EVENING OR NIGHTTIME HOURS. AT THIS TIME, THE RAP AND GFS ARE
DOING A DECENT JOB OF INITIALIZING THE LATEST UPPER AIR CONDITIONS
AND INDICATE A NEAR-SURFACE CAP THURSDAY EVENING WITH MUCAPE OF
1,000-2,000 J/KG AND STEEP MID-LEVEL LAPSE RATES SUPPORTIVE OF AT
LEAST 1" HAIL FURTHER WEST BEFORE TRENDING DOWNWARD OVERNIGHT.
THE MAIN DIFFERENCE IS THAT THE GFS, WHICH CAN BE VIEWED AS THE
REASONABLE WORST CASE SCENARIO AT THIS POINT, PORTRAYS A DRIER AND
MORE UNSTABLE AIRMASS BY THE TIME CONVECTION INITIATES, WITH
MUCAPE VALUES EXCEEDING 2,000 J/KG ALONG/WEST OF US-281, STEEPER
LOW-LEVEL LAPSE RATES AND HIGHER SURFACE-BASED CAPE VALUES,
THOUGH CAPPED. IN THE GFS SOLUTION, DEEP AND STRONG CONVECTION
DEVELOPING TO THE NORTHWEST WOULD POSE A PRIMARY HAIL THREAT
EARLIER IN THE EVENT BEFORE TRANSITIONING A TO STRONG TO DAMAGING
WIND THREAT AS STORMS MOVE SOUTHEASTWARD AND POTENTIALLY BREAK THE
CAP.
ON THE FLIP SIDE, SOME CAMS, SUCH AS THE 18Z NAM 3KM RUN, INDICATE
THE FRONT SWEEPING QUICKLY THROUGH THE REGION THURSDAY MORNING,
BRINGING STABLE AIR AND COOLER TEMPERATURES BEHIND AND LITTLE
PRECIPITATION, IF ANY AT ALL, INTO THURSDAY NIGHT. THUS, THE
SEVERE RISK REMAINS CONDITIONAL AT THIS TIME. REGARDLESS, THE
FRONT IS EXPECTED TO HAVE MOVED THROUGH AT SOME POINT BY THURSDAY
EVENING OR THURSDAY NIGHT. A LOW TO MEDIUM (30-60%) CHANCE OF
RAIN CONTINUES INTO FRIDAY AS A POTENTIAL MID- LEVEL DISTURBANCE
MOVES THROUGH AHEAD OF A CUT-OFF LOW ALOFT TO THE WEST. HIGH
TEMPERATURES RISE FROM THE 80S/90S ON FRIDAY BACK TO WIDESPREAD
90S ON SATURDAY AND SUNDAY, WITH A MODERATE HEAT RISK POSSIBLE ON
SUNDAY. A WEAK COLD FRONT IS POSSIBLE SUNDAY NIGHT OR MONDAY,
WHICH COULD BRING A LOW CHANCE OF UNSETTLED WEATHER FOR THE
BEGINNING OF NEXT WEEK.
A MEDIUM RISK OF RIP CURRENTS CONTINUES THROUGH WEDNESDAY
AFTERNOON.
AVIATION
(12Z TAFS)
ISSUED AT 547 AM CDT WED MAY 6 2026
LOW MVFR STRATUS AND MODERATE SOUTHEAST WINDS PREVAIL ACROSS DEEP
SOUTH TEXAS EARLY THIS MORNING. RECENT OBSERVATIONS INDICATE IFR
CEILINGS AT BRO. THEREFORE, WILL INCLUDE A TEMPO FOR BRO THROUGH
14Z. OTHERWISE, MVFR CEILINGS ARE EXPECTED TO CONTINUE THROUGH
AROUND MID-MORNING. SOUTHEAST WINDS WILL BECOME GUSTY MID TO LATE
MORNING WITH SOME GUSTS BETWEEN 20 TO 25 KNOTS POSSIBLE IN THE
AFTERNOON AT BRO AND HRL. LIGHTER WINDS, SHIFTING TO THE EAST, ARE
EXPECTED AT MFE IN THE AFTERNOON AS A DRYLINE/SURFACE BOUNDARY
APPROACHES THE TERMINAL. VFR CONDITIONS ARE FORECAST MID TO LATE
MORNING WITH MVFR RETURNING THIS EVENING AND POSSIBLE IFR CEILINGS
OVERNIGHT.
MARINE
ISSUED AT 1040 PM CDT TUE MAY 5 2026
THE PRESSURE GRADIENT CONTINUES TO LOOSEN ACROSS THE REGION, THOUGH
SMALL CRAFT EXERCISE CAUTION HEADLINES CONTINUE THROUGH TONIGHT AS
MODERATE TO FRESH SOUTHEASTERLY WINDS AND MODERATE (3-5 FT) SEAS
GRADUALLY REDUCE TO MODERATE ON WEDNESDAY AND GENTLE TO MODERATE
WEDNESDAY NIGHT WITH SLIGHT TO MODERATE (2-4 FT) SEAS. A COLD FRONT
LIKELY MOVES THROUGH THURSDAY AFTERNOON OR EVENING, INCREASING
CHANCES OF RAIN THURSDAY AFTERNOON TO AS MUCH AS A LOW TO MEDIUM (20-
50%) CHANCE THURSDAY NIGHT INTO FRIDAY MORNING AS WINDS SHIFT TO
NORTHEASTERLY ALONG WITH MODERATE SEAS. GENTLE TO MODERATE
SOUTHEASTERLY WINDS AND SLIGHT TO MODERATE SEAS RESUME SUNDAY
BEFORE ANOTHER POSSIBLE WEAK COLD FRONT AND LOW CHANCE OF UNSETTLED
WEATHER ARRIVE INTO THE BEGINNING OF NEXT WEEK.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 96 79 92 78 / 0 0 30 50
HARLINGEN 99 77 92 74 / 0 0 40 60
MCALLEN 101 79 94 76 / 0 0 50 70
RIO GRANDE CITY 100 78 92 74 / 0 0 40 80
SOUTH PADRE ISLAND 86 78 84 78 / 0 0 10 40
BAYVIEW/PORT ISABEL 95 78 89 77 / 0 0 30 50
BRO WATCHES/WARNINGS/ADVISORIES
TX...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING
FOR TXZ251-253>255.
GM...NONE.
SHORT TERM...65-IRISH
LONG TERM....65-IRISH
AVIATION...63-KC
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