302
FXUS64 KBRO 081828
AFDBRO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
128 PM CDT WED JUL 8 2026
..NEW DISCUSSION, AVIATION, MARINE
KEY MESSAGES
UPDATED AT 114 PM CDT WED JUL 8 2026
* HOT SUMMER CONDITIONS CONTINUE THROUGH THE WEEK. MODERATE (LEVEL 2
OF 4) HEAT RISK EACH DAY, MAINLY IN THE VALLEY BECOMING MORE
WIDESPREAD THIS WEEKEND. HEAT INDICES WILL CLIMB TO BETWEEN 100
AND 110 DEGREES EACH DAY.
* DAILY RAIN AND THUNDERSTORM CHANCES WILL INCREASE FROM 10-25%
WEDNESDAY/THURSDAY TO 25-40% FRIDAY/SATURDAY. WHILE SEVERE
WEATHER IS NOT EXPECTED, ANY STORMS THAT DEVELOP ARE CAPABLE OF
HEAVY TO TORRENTIAL RAINFALL, GUSTY WINDS AND SMALL HAIL.
* THERE IS GENERALLY A LOW RISK OF RIP CURRENTS AT AREA BEACHES
LIKELY INCREASING TO MODERATE THIS WEEKEND.
DISCUSSION
ISSUED AT 114 PM CDT WED JUL 8 2026
OUR REGION IS CURRENTLY SANDWICHED BETWEEN AN AREA OF UPPER LEVEL
LOW PRESSURE ACROSS CENTRAL MEXICO AND ANOTHER AREA OF UPPER LEVEL
LOW ACROSS THE TENNESSEE AND MISSISSIPPI VALLEY. IN OTHER WORDS,
DEEP SOUTH TEXAS IS SITUATED WITHIN A NARROW CORRIDOR OF UPPER LEVEL
RIDGE. LATEST SUITE OF HI-RES AND GLOBAL GUIDANCE REMAIN IN
AGREEMENT THAT THE GENERALLY BENIGN WEATHER SHOULD CONTINUE THROUGH
THURSDAY MORNING, WITH SHOWER AND THUNDERSTORMS COVERAGE REMAINING
ISOLATED TO WIDELY SCATTERED AND TRANSIENT IN NATURE. EARLIER THIS
MORNING, COMPOSITE RADAR AND VISIBLE SATELLITE SHOWS AN AREA OF
DISORGANIZED CONVECTION MOVING NORTHWARDS FROM TAMAULIPAS AND
FALLING APART AS IT APPROACHES THE INTERNATIONAL BORDER. SURFACE OBS
ALSO INDICATE DRIER AIR FROM THE TOP OF THE BOUNDARY LAYER MIXING
DOWN, WITH MOSTLY TO PARTLY SUNNY SKIES PREVAILING AWAY FROM THE
COAST AND DEW POINTS FALLING INTO THE LOW 70S FROM UPPER 70S.
PWAT VALUES ARE ABOUT 1.8 INCHES, WHICH IS AROUND THE 75TH
PERCENTILE OF SPC SOUNDING CLIMATOLOGY FOR OUR AREA. WHILE THERE IS
NEGLIGIBLE SHEAR TO GET STORMS ORGANIZED, ANY STORMS THAT DO DEVELOP
IS CAPABLE OF LOCALLY HEAVY DOWNPOURS, GUSTY WINDS AND EVEN SMALL
HAIL. OTHERWISE, CHANCE OF SHOWERS AND THUNDERSTORMS INCREASE FROM
10-25 PERCENT TODAY/THURSDAY TO 25-40 PERCENT FOR FRIDAY/SATURDAY.
THIS IS BECAUSE A SURGE OF TROPICAL MOISTURE LOOKS TO APPROACH OUR
REGION FROM THE SOUTHEAST BY THURSDAY AND CERTAINLY INTO FRIDAY.
PWATS INCREASE TO BETWEEN 2 TO 2.2 INCHES, WHICH IS 90-95TH
PERCENTILE OF SOUNDING CLIMATOLOGY FOR THE BROWNSVILLE, TX UPPER
AIR SITE. CURRENTLY, THERE ARE NO EXCESSIVE RAINFALL OUTLOOKS FROM
WPC FOR OUR AREA DUE TO LOW CONFIDENCE IN FLASH FLOODING BUT THIS
IS SOMETHING TO MONITOR IN THE COMING DAYS. 1-HOUR FLASH FLOOD
GUIDANCE ACROSS THE RGV IS QUITE HIGH, WITH 2.5 TO 3.5 INCHES PER
HOUR ACCORDING TO WGRFC OWING TO THE FACT THAT IT HAS BEEN OVER
THREE WEEKS SINCE OUR LAST WIDESPREAD RAINFALL.
ONE THING TO NOTE IS THAT WHILE THE OFFICIAL FORECAST MIGHT
INDICATE A LACK OF AREA WIDE SIGNIFICANT RAINFALL, SUCH AN
ENVIRONMENT IS CAPABLE OF PRODUCING HIGHLY EFFICIENT RAINFALL
RATES WITH LOCALLY QUICK COUPLE OF INCHES OF RAINFALL IN JUST 30
TO 45 MINUTES. IT IS ALMOST IMPOSSIBLE TO PINPOINT EXACTLY WHERE
AHEAD OF TIME, HOWEVER, GIVEN THE ISOLATED TO WIDELY SCATTERED
NATURE OF THE SHOWERS AND THUNDERSTORMS. IN THE ABSENCE OF SHEAR,
THE MAIN TRIGGERS FOR LOCALLY HEAVY RAINFALL AND ISOLATED STORMS
WILL BE THE SEA BREEZE AND LOCAL OUTFLOW BOUNDARIES, WHICH CAN BE
QUITE MESSY IN A WEAKLY FORCED ENVIRONMENT. BOTTOM LINE, IF YOU DO
HAVE OUTDOOR PLANS, PLEASE KEEP AN EYE TO THE SKY AND BE READY TO
GO INDOORS IF THUNDER ROARS. DRIER WEATHER LOOKS TO RETURN FOR
SUNDAY INTO EARLY NEXT WEEK. EARLY INDICATIONS ARE THAT RAIN
CHANCES WOULD INCREASE TOWARDS MIDDLE PART OF NEXT WEEK AS A COLD
FRONT APPROACHES FROM THE NORTH BUT CONFIDENCE IS LOW THIS FAR
OUT. LOOKING AT THE CPC 6-10 DAY OUTLOOK, THERE IS A 40-50 PERCENT
PROBABILITY OF ABOVE NORMAL RAINFALL AND 33-50 PERCENT
PROBABILITY OF ABOVE NORMAL TEMPERATURES FOR OUR CWA.
TYPICAL MID-SUMMER TEMPERATURES INTO THE MID TO UPPER 90S FOR MOST
INLAND LOCATIONS CONTINUE, WITH A COOLER BEACH AND WARMER BRUSH
COUNTRY. EXPECT A MODERATE (LEVEL 2 OF 4) HEAT RISK THROUGH MUCH OF
THE FORECAST PERIOD, WITH BRIEF RELIEF WHERE CLOUDS, SHOWERS, OR
THUNDERSTORMS CAN DEVELOP. COMBINED WITH THE OPPRESSIVE HUMIDITY
WITH DEW POINTS IN THE MID TO UPPER 70S, HEAT INDEX VALUES ARE
EXPECTED TO TOP OUT IN THE 105-110 RANGE AWAY FROM THE COAST.
LONG PERIOD SWELL INCREASES INTO THE WEEKEND AND EARLY NEXT WEEK
OFFSHORE, POTENTIALLY BRINGING A MODERATE RISK OF LIFE-THREATENING
RIP CURRENTS ALONG THE LOWER TEXAS COAST. ASTRONOMICAL TIDES BUILD
THIS WEEKEND AS WE NEAR THE NEW MOON, WHICH MAY NARROW ALREADY
NARROW BEACHES AT HIGH TIDE CYCLES THIS WEEKEND INTO NEXT WEEK.
AVIATION
(18Z TAFS)
ISSUED AT 114 PM CDT WED JUL 8 2026
VFR IS ANTICIPATED AT THE TERMINALS THROUGH THE NEXT 12 TO 18 HOURS.
BREEZY SOUTH-SOUTHEAST OR SOUTHERLY WINDS WITH 15-20 KT GUSTS AT
TIMES DURING THE DAYLIGHT HOURS WILL BECOME LIGHT FOR THE NIGHTTIME.
CLEAR TO PARTLY CLOUDY SKIES WILL ALSO PREVAIL THROUGH THURSDAY 12Z.
TOWARDS THE END OF THE TAF PERIOD, THE PROBABILITY OF MVFR
CONDITIONS INCREASE AS CHANCE FOR DIURNAL SHOWERS AND ISOLATED
THUNDERSTORMS INCREASE BY MID DAY THURSDAY.
MARINE
ISSUED AT 114 PM CDT WED JUL 8 2026
LIGHT TO MODERATE SOUTH-SOUTHEASTERLY WINDS CONTINUE ACROSS THE
COASTAL WATERS THROUGH MOST OF THE FORECAST PERIOD WITH STRONG HIGH
PRESSURE NORTHWEST OF THE GULF. THE ONLY EXCEPTION WILL BE DURING
PERIODS OF THUNDERSTORMS, WHERE BRIEF PERIODS OF STRONG WIND GUSTS
ALONG WITH LOCALLY HEAVY RAINFALL WILL BE POSSIBLE ESPECIALLY DURING
THE AFTERNOON HOURS. EXPECT AN AFTERNOON CHOP EACH DAY ON THE BAY,
WITH GULF SEAS OF GENERALLY 2 TO 3 FEET, GRADUALLY BUILDING TOWARDS
3 TO 4 FEET LATE THIS WEEKEND INTO NEXT WEEK WITH LONGER PERIOD
SWELLS.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 78 93 79 93 / 0 20 30 30
HARLINGEN 75 94 76 94 / 0 20 20 30
MCALLEN 77 97 79 97 / 0 20 10 30
RIO GRANDE CITY 76 97 77 97 / 0 20 0 30
SOUTH PADRE ISLAND 80 87 81 87 / 0 30 40 40
BAYVIEW/PORT ISABEL 77 91 78 91 / 0 20 30 30
BRO WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...NONE.
SHORT TERM...88-CHAI
LONG TERM....88-CHAI
AVIATION...88-CHAI
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