197
FXUS64 KBRO 010339
AFDBRO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1039 PM CDT THU APR 30 2026
..NEW DISCUSSION, MARINE
KEY MESSAGES
UPDATED AT 1012 PM CDT THU APR 30 2026
KEY MESSAGES:
* ONE MORE DAY OF HOT TEMPERATURES ON FRIDAY, WITH A MINOR TO
MODERATE HEAT RISK (LEVELS 1 AND 2 OUT OF 4) AS AFTERNOON HEAT
INDICES REACH INTO THE LOWER 100S ACROSS MOST OF THE RGV.
* SHOWERS AND THUNDERSTORMS BRING A LOW TO MEDIUM (20-50%) CHANCE
OF RAIN TO THE NORTHERN RANCHLANDS FRIDAY MORNING AND AFTERNOON,
FOLLOWED BY A LOW TO MEDIUM (30-60%) CHANCE FOR THE REST OF
THE REGION FRIDAY EVENING INTO THE NIGHTTIME HOURS.
* FORECAST CONFIDENCE REMAINS LOW AT THIS TIME FOR THE LIKELIHOOD
OF ISOLATED STRONG TO SEVERE THUNDERSTORMS LATE TONIGHT THROUGH
FRIDAY NIGHT.
* HIGH SURF ADVISORY AND SMALL CRAFT ADVISORY GO INTO EFFECT
FRIDAY NIGHT AS BREEZY TO STRONG NORTHERLY WINDS ALONG/BEHIND
THE FRONT RESULT IN LARGE BREAKING WAVES, LIFE THREATENING RIP
CURRENTS AND ADVERSE MARINE CONDITIONS INTO SATURDAY NIGHT.
* TEMPERATURES DROP AT LEAST 15-20 DEGREES BEHIND THE FRONT
FRIDAY NIGHT INTO SATURDAY BEFORE STEADILY RISING ON SUNDAY
BACK TO ABOVE AVERAGE BY NEXT TUESDAY.
DISCUSSION
ISSUED AT 1012 PM CDT THU APR 30 2026
SURFACE OBSERVATIONS AND RADAR IMAGERY THIS EVENING REVEAL A
STATIONARY BOUNDARY DRAPED ACROSS THE RIO GRANDE PLAINS AND THE
NORTHERN RANCHLANDS AS WELL AS CONVECTION FIRING OFF THE SIERRA
MADRE TO THE NORTHWEST AND SOUTHERN-CENTRAL TEXAS, WHERE FORCING
FROM UPPER LEVEL DIVERGENCE AND ASCENT ALOFT ARE ENHANCING AHEAD OF
A MID/UPPER LEVEL TROUGH MOVING INTO NORTHERN MEXICO. AS THE TROUGH
DRAWS FURTHER EAST AND ASSOCIATED FORCING EXPANDS SOUTHEASTWARD
TONIGHT, SHOWERS AND THUNDERSTORMS ARE ANTICIPATED TO DEVELOP
PROGRESSIVELY FURTHER SOUTH AND INTO SOUTHERN TEXAS BY FRIDAY
MORNING. AT THIS TIME, THE CONVECTION ALLOWING MODELS (CAMS) BEST
INITIALIZING THE LATEST CONDITIONS ARE INDICATING STRONG TO SEVERE
THUNDERSTORMS REMAINING WELL NORTH OF DEEP SOUTH TEXAS TONIGHT INTO
FRIDAY MORNING. YET, THE NAM 3 KM AND HRRR BRING THE CONVECTION
FURTHER SOUTH AND INITIATING OFF THE FRONTAL BOUNDARY, WHERE THE
HRRR CLIPS THE EXTREME NORTHERN PORTIONS OF ZAPATA, JIM HOGG,
BROOKS AND KENEDY COUNTIES WITH SHOWERS AND ISOLATED, BUT SHORT-
LIVED, STRONG TO POTENTIALLY SEVERE THUNDERSTORMS AT SOME POINT
FROM LATE TONIGHT THROUGH THE MID-MORNING HOURS ON FRIDAY. AS
SUCH, SPC DOES INCLUDE THOSE AREAS WITHIN A MARGINAL (LEVEL 1/5)
RISK OF SEVERE THUNDERSTORMS, WITH THE PRIMARY THREAT OF ISOLATED
LARGE (1"+) HAIL AND STRONG WIND GUSTS TRANSITIONING TO A HAIL
RISK IN THE MORNING DUE TO DEEP LAYER SHEAR IN PLACE ALONG WITH
RELATIVELY STEEP LOWER/MID-LEVEL LAPSE RATES AND MARGINALLY
SUFFICIENT MUCAPE. HOWEVER, IT SHOULD BE NOTED THAT THE HRRR IS AN
OUTLIER AT THIS POINT AND THE MORE LIKELY SCENARIO IS THAT THE
STRONG TO SEVERE THREAT REMAINS WELL TO THE NORTH WHILE LIGHT TO
MODERATE SHOWERS, AND POTENTIALLY A RUMBLE OF THUNDER OR TWO,
BRING A LOW TO MEDIUM (20-50%) CHANCE OF RAIN TO THE RIO GRANDE
PLAINS AND THE NORTHERN RANCHLANDS FRIDAY MORNING INTO THE
AFTERNOON. TEMPERATURES MINIMIZE IN THE 70S TONIGHT ALONG WITH
MUGGY CONDITIONS.
THE TROUGH EJECTS EASTWARD AND NORTH OF OUR REGION DURING THE DAY
FRIDAY AND SURFACE HIGH PRESSURE AND NORTHERLY WINDS ON THE
BACKSIDE OF THE ASSOCIATED SURFACE LOW PRESSURE SYSTEM SEND A COLD
FRONT SOUTHWARD THROUGH DEEP SOUTH TEXAS LATE FRIDAY AFTERNOON
INTO FRIDAY NIGHT, INCREASING CHANCES OF RAIN TO AS MUCH AS A LOW
TO MEDIUM (30-60%) CHANCE FRIDAY NIGHT FOR AREAS SOUTH OF THE
NORTHERN RANCHLANDS. THIS WILL BE ANOTHER PERIOD TO WATCH FOR ANY
STRONGER STORM POTENTIAL; THE RAP AND GFS POSE A SMALL WINDOW OF
ATMOSPHERIC INSTABILITY AND STEEP LAPSE RATES COINCIDING WITH
CONVECTION DEVELOPING WITH THE FRONT TO DEVELOP ISOLATED STRONG TO
SEVERE THUNDERSTORMS. YET, AGAIN, CAM SOLUTIONS STILL REMAIN VERY
INCOHESIVE AND CONFIDENCE IS TOO LOW TO SAY ONE WAY OR THE OTHER
BEYOND THE CURRENT EXPECTATION OF PASSING ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS BRINGING GENERALLY AROUND 0.3-0.7 OF AN
INCH OF RAIN TO THE LOWER AND MIDDLE RGV.
TEMPERATURE-WISE, ANOTHER HOT DAY IS ANTICIPATED AHEAD OF THE
FRONT ON FRIDAY, REACHING INTO THE LOW/MID 90S FOR MOST, THOUGH
CLOUD COVERAGE OVER THE RIO GRANDE PLAINS AND WESTERN PORTIONS OF
THE BRUSH COUNTRY COULD KEEP TEMPERATURES IN THE 80S. AFTERNOON
HEAT INDICES IN THE LOWER 100S ARE LIKELY ACROSS MOST OF THE RGV,
BRINGING MAINLY A MINOR HEAT RISK TO THE CWA AS WELL AS A MODERATE
HEAT RISK ROUGHLY BETWEEN US-281 AND I-69 E. BEHIND THE FRONT,
BREEZY NORTHERLY WINDS, GUSTING TO 20-30+ MPH, ADVECT MUCH COOLER,
DRIER AND REFRESHING AIR, DROPPING TEMPERATURES DOWN TO THE UPPER
50S/LOWER 60S BY SATURDAY MORNING AND ONLY RISING INTO THE
MID/UPPER 70S SATURDAY AFTERNOON, WHICH IS A GOOD 15-20 DEGREES
COOLER THAN FRIDAY. RIDGING ALOFT AND THE RETURN OF SOUTHEASTERLY
WINDS BY MONDAY MODERATE AND WARM TEMPERATURES BACK TO ABOVE
NORMAL BY NEXT TUESDAY. THE NEXT POTENTIAL COLD FRONT AND
UNSETTLED WEATHER COULD BE BY THE LATER PART OF NEXT WEEK.
DUE TO GUSTY NORTHERLY WINDS ALONG THE COAST AND STRONG WINDS OVER
THE GULF BEHIND THE FRONT, A HIGH SURF ADVISORY GOES INTO EFFECT 1
AM SATURDAY MORNING UNTIL 1 AM SUNDAY MORNING FOR LARGE BREAKING
WAVES OF 6-10 FEET. ADDITIONALLY, A HIGH RISK OF RIP CURRENTS IS
LIKELY TO BE ISSUED OVERNIGHT TONIGHT OR ON FRIDAY AS WINDS AND
LARGE WAVES LEAD TO LIFE-THREATENING RIP CURRENTS, LASTING POSSIBLY
INTO THE BEGINNING OF NEXT WEEK.
AVIATION
(00Z TAFS)
ISSUED AT 650 PM CDT THU APR 30 2026
GENTLE TO MODERATE SOUTHEASTERLY WINDS CONTINUE THIS EVENING INTO
THE NEXT COUPLE OF HOURS, AROUND 10-15 KNOTS, BEFORE SETTLING
AROUND 5-10 KNOTS OVERNIGHT. BROKEN TO OVERCAST VFR CEILINGS ARE
LIKELY TO DROP DOWN TO MVFR TONIGHT, POSSIBLY LOWERING TO IFR AT
KMFE AND KBRO, WITH THE GREATEST IFR PROBABILITIES AT KMFE.
OTHERWISE, SCATTERED TO BROKEN VFR SKIES GRADUALLY RETURN TO ALL
TERMINALS BY MID TO LATE FRIDAY MORNING AS SOUTHEASTERLY WINDS
PICK BACK UP TO AROUND 10-15 KNOTS BY THE AFTERNOON.
MARINE
ISSUED AT 1012 PM CDT THU APR 30 2026
GENTLE TO MODERATE SOUTHEASTERLY WINDS AND SLIGHT TO MODERATE (2-4
FT) SEAS CONTINUE TONIGHT THROUGH FRIDAY AFTERNOON AHEAD OF A COLD
FRONT ARRIVING IN THE EVENING INTO FRIDAY NIGHT. A SMALL CRAFT
ADVISORY GOES INTO EFFECT FOR ALL LOWER TEXAS COASTAL WATERS (0-60
NM OUT) FROM 7 PM FRIDAY EVENING UNTIL 1 AM SUNDAY MORNING AS STRONG
NORTHERLY WINDS AND NEAR GALE FORCE GUSTS ALONG AND BEHIND THE FRONT
RESULT IN MODERATE TO ROUGH (6-10 FT, OR GREATER) SEAS AND ROUGH
CONDITIONS ON THE BAY INTO LATE SATURDAY NIGHT. DEVELOPING SHOWERS
AND THUNDERSTORMS AHEAD OF AND ALONG THE FRONT INCREASE CHANCES OF
RAIN NORTH TO SOUTH FROM LATE FRIDAY AFTERNOON TO AS MUCH AS A LOW
TO MEDIUM (30-60%) CHANCE LATE FRIDAY NIGHT. ALTHOUGH CONFIDENCE AND
CHANCES ARE LOW AT THIS TIME, THERE IS A SLIGHT POTENTIAL FOR
ISOLATED STRONG TO SEVERE THUNDERSTORMS AS THE UNSETTLED WEATHER
ARRIVES. OTHERWISE, CHANCES OF RAIN DECREASE THROUGHOUT THE DAY
SATURDAY AND WINDS AND SEAS IMPROVE THROUGHOUT THE REMAINDER OF
SATURDAY NIGHT AND INTO THE REST OF THE WEEKEND. GENTLE TO MODERATE
WINDS AND MODERATE SEAS RESUME ON SUNDAY, BECOMING SOUTHEASTERLY ON
MONDAY, WITH MODERATE TO FRESH WINDS AND PERIODS OF SMALL CRAFT
EXERCISE CAUTION CONDITIONS DEVELOPING BY MIDWEEK.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 76 92 61 74 / 0 0 60 40
HARLINGEN 73 94 59 76 / 0 10 60 20
MCALLEN 77 96 62 77 / 0 10 60 20
RIO GRANDE CITY 75 93 59 77 / 10 20 40 10
SOUTH PADRE ISLAND 76 83 66 73 / 0 0 60 40
BAYVIEW/PORT ISABEL 74 90 61 74 / 0 10 60 30
BRO WATCHES/WARNINGS/ADVISORIES
TX...HIGH SURF ADVISORY FROM 1 AM SATURDAY TO 1 AM CDT SUNDAY FOR
TXZ451-454-455.
GM...SMALL CRAFT ADVISORY FROM 7 PM FRIDAY TO 1 AM CDT SUNDAY FOR
GMZ130-132-135-150-155-170-175.
SHORT TERM...65-IRISH
LONG TERM....65-IRISH
AVIATION...65-IRISH
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