706
FXUS64 KBRO 220552 AAB
AFDBRO
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1252 AM CDT THU MAY 22 2025
..NEW AVIATION
SHORT TERM
(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 140 PM CDT WED MAY 21 2025
KEY MESSAGES:
- MARGINAL RISK FOR SEVERE THUNDERSTORMS AND EXCESSIVE
RAINFALL ACROSS DEEP SOUTH TEXAS LATE THIS EVENING AND TONIGHT.
- MINOR TO MODERATE HEAT RISK ON THURSDAY.
THE MAIN WEATHER CONCERN IN THE SHORT TERM PERIOD IS THE POTENTIAL
FOR ISOLATED STRONG TO SEVERE THUNDERSTORMS WITH A THREAT FOR
DAMAGING WIND GUSTS, HAIL, AND HEAVY RAINFALL. THE LATEST RADAR AND
SATELLITE IMAGERY REVEAL PARTLY TO MOSTLY CLOUDY SKIES ACROSS DEEP
SOUTH TEXAS, WITH WIDELY SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SOUTH OF THE RIO GRANDE RIVER. ADDITIONAL CONVECTION
IS EXPECTED TO DEVELOP OFF OF THE SIERRA MADRE IN MEXICO AS AN
APPROACHING SHORTWAVE INTERACTS WITH A FAVORABLE PARAMETER SPACE -
MUCAPE UPWARDS OF 3000 J/KG, PWATS UPWARDS OF 2 INCHES, MID LEVEL
LAPSE RATES AROUND 7-7.5 C/KM, AND BULK SHEAR VALUES UPWARDS OF 35
KNOTS. INITIAL CONVECTION IS EXPECTED TO BE DISCRETE, BUT SHOULD
GROW UPSCALE INTO AN MCS/CLUSTER OF CONVECTION AND TRANSLATE TOWARDS
THE EAST/SOUTHEAST TOWARDS THE RIO GRANDE VALLEY AND PORTIONS OF
THE NORTHERN RANCHLANDS.
THERE ARE STILL DISCREPANCIES ON THE TIMING AND EVOLUTION OF
CONVECTIVE DEVELOPMENT AMONG THE LATEST SUITE OF HIGH RES GUIDANCE,
BUT THERE ARE INDICATES THAT THE BEST POTENTIAL FOR ANY ACTIVITY
WILL BE ALONG AND WEST OF US-281 WITH LOW TO MEDIUM CHANCES (AROUND
30-50%) BETWEEN 8PM AND 1AM, AND LOW CHANCES (20-30%) ALONG AND EAST
OF US-281 BETWEEN 10PM AND 2AM. SHOULD ANY SEVERE THUNDERSTORMS
DEVELOP, THE PRIMARY THREATS WILL BE DAMAGING WIND GUSTS AND HAIL.
GIVEN THE PRESENCE OF HIGH MOISTURE CONTENT ACROSS THE REGION,
EFFECTIVE RAIN-PRODUCING SHOWERS AND THUNDERSTORMS MAY RESULT IN
ISOLATED HIGHER AMOUNTS UPWARDS OF 2-3 INCHES WHICH MAY RESULT IN
ISOLATED FLASH FLOODING ISSUES. THIS IS HIGHLIGHTED WITH THE LATEST
HREF GUIDANCE, WHICH INDICATES THE BEST POTENTIAL FOR ISOLATED
HIGHER AMOUNTS RESIDES ALONG AND WEST OF US-281. THIS ACTIVITY
SHOULD COME TO AN END PRIOR TO SUNRISE ON THURSDAY.
THURSDAY AND THURSDAY NIGHT WILL FEATURE RAIN-FREE CONDITIONS AND
WARM TEMPERATURES ONCE AGAIN. EXPECT HIGHS IN THE MID TO UPPER 90S
AND LOWS IN THE MID TO UPPER 70S. IN COMBINATION WITH THE HUMIDITY,
HEAT INDEX VALUES WILL RANGE FROM 100 TO 106 DEGREES DURING THE
AFTERNOON HOURS. A MINOR TO MODERATE HEAT RISK WILL CONTINUE ON
THURSDAY.
LONG TERM
(FRIDAY THROUGH NEXT WEDNESDAY)
ISSUED AT 140 PM CDT WED MAY 21 2025
RIDGING ALOFT AND SURFACE HIGH PRESSURE OVER THE GULF WILL CONTINUE
INTO RESULT IN HOT AND DRY CONDITIONS WITH SOUTHEASTERLY TO
SOUTHERLY WINDS FRIDAY INTO MONDAY. OVER THE WEEKEND, A MID-UPPER
LEVEL TROUGH AND SURFACE LOW PRESSURE SYSTEM WILL MOVE EASTWARD
FROM THE WEST COAST INTO THE CENTRAL PLAINS, RESULTING IN A
TIGHTENED PRESSURE GRADIENT BETWEEN THE SURFACE HIGH TO THE EAST
AND PRESSURE FALLS OVER THE SIERRA MADRE. THIS WILL LEAD TO BREEZY
CONDITIONS BEGINNING SATURDAY AND LASTING INTO MONDAY. MEANWHILE,
THE TROUGH WILL BEGIN TO MODIFY AND WEAKEN RIDGING ALOFT THROUGH
THE LATER PART OF THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK AS
ANOTHER TROUGH PUSHES INTO THE WEST COAST. AT THE SURFACE, A COLD
FRONT, TRAILING BEHIND THE FIRST TROUGH AND SURFACE LOW, WILL
ADVANCE SOUTHWARD THROUGH TEXAS MONDAY INTO TUESDAY, STALLING
NORTH OF DEEP SOUTH TEXAS INTO WEDNESDAY. MOISTURE POOLING AND
EAST-SOUTHEASTERLY SURFACE WINDS SOUTH OF THE FRONT WILL ADVECT
MOISTURE INTO OUR REGION AND INCREASE PROBABILITIES OF SHOWERS
AND THUNDERSTORMS FROM A LOW TO MODERATE (20-30) CHANCE ON MONDAY
TO A MODERATE (30-40%) CHANCE MONDAY AFTERNOON AND EVENING INTO
WEDNESDAY.
TEMPERATURES WILL BE HOT FOR THE FIRST HALF OF THE LONG TERM,
FEATURING 90S ACROSS INLAND AREAS AND EVEN IN THE LOW 100S ACROSS
ZAPATA OVER THE WEEKEND. SATURDAY AND SUNDAY LOOK TO BE THE
HOTTEST WITH HEAT INDICES POSSIBLY AROUND 108-111 DEGREES F FOR A
FEW HOURS IN THE AFTERNOON, RESULTING IN A MODERATE (LEVEL 2 OF
4) TO MAJOR (LEVEL 3 OF 4) HEAT RISK. SIMILAR TEMPERATURES ARE
EXPECTED MONDAY, THOUGH A FEW DEGREES COOLER AS CLOUDS BUILD.
INCREASED CLOUD COVERAGE TUESDAY AND WEDNESDAY SHOULD KEEP HIGHS
IN THE UPPER 80S TO LOW 90S ACROSS THE COUNTY WARNING AREA. LOWS
ARE EXPECTED TO DECREASE FROM THE MID TO UPPER 70S, AS WARM AS
LOWER 80S ACROSS SPI AND THE LOWER RGV, FRIDAY THROUGH SUNDAY
NIGHT DOWN TO THE LOW TO MID 70S MONDAY NIGHT AND TUESDAY NIGHT.
HIGHS WILL LIKELY REMAIN IN THE LOW TO MID 80S AT SPI.
AVIATION
(06Z TAFS)
ISSUED AT 1242 AM CDT THU MAY 22 2025
BRO RADAR CURRENTLY INDICATES A LARGE AREA OF CONVECTION, MAINLY
SOUTH OF THE RIO GRANDE RIVER. THESE SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO CONTINUE TO MOVE EASTWARD FOR THE NEXT SEVERAL HOURS AND
REMAIN SOUTH THE OF TERMINALS. BRIEF VCSH OR A RUMBLE OR TWO OF
THUNDER WILL BE POSSIBLE AS THE CONVECTION PASSES SOUTH OF THE
AREA. VFR CONDITIONS WITH LIGHT TO MODERATE EAST TO SOUTHEAST
WINDS WILL PREVAIL FOR THE NEXT 24 HOURS.
MARINE
ISSUED AT 140 PM CDT WED MAY 21 2025
TONIGHT THROUGH THURSDAY NIGHT...GENERALLY FAVORABLE MARINE
CONDITIONS WITH PREVAIL WITH LOW TO MODERATE SEAS AND LIGHT TO
MODERATE WINDS. THERE IS A POTENTIAL FOR SHOWERS AND THUNDERSTORMS
LATE TONIGHT OVER THE LAGUNA MADRE AND GULF WATERS. WHILE THIS
ACTIVITY SHOULD BE ON THE DOWNWARD TREND BY THE TIME IT REACHES THE
COAST, GUSTY WINDS, LIGHTNING, AND HEAVY RAINFALL WILL BE POSSIBLE.
PRECIPITATION CHANCES COME TO AN END BY THURSDAY MORNING.
FRIDAY THROUGH NEXT WEDNESDAY...GENTLE TO MODERATE SOUTHEASTERLY
WINDS, ACCOMPANIED BY SLIGHT SEAS, ON FRIDAY WILL BECOME MODERATE TO
FRESH SATURDAY THROUGH SUNDAY AS A PRESSURE GRADIENT TIGHTENS,
LEADING TO MODERATE SEAS AND LIKELY SMALL CRAFT EXERCISE CAUTION
HEADLINES. GENTLE TO MODERATE WINDS RETURN MONDAY INTO WEDNESDAY, AS
THE GRADIENT LOOSENS, TURNING EASTERLY ON TUESDAY. MEANWHILE, THE
PROBABILITY OF SHOWERS AND THUNDERSTORMS INCREASES TO A LOW TO
MODERATE (20-40%) CHANCE MONDAY INTO WEDNESDAY.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 78 92 79 92 / 0 0 0 10
HARLINGEN 75 94 76 95 / 0 0 0 0
MCALLEN 78 96 79 98 / 0 0 0 0
RIO GRANDE CITY 75 96 76 97 / 10 0 0 0
SOUTH PADRE ISLAND 78 86 79 86 / 0 10 0 10
BAYVIEW/PORT ISABEL 77 90 77 90 / 0 0 0 0
BRO WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...NONE.
SHORT TERM...22-GARCIA
LONG TERM....65-IRISH
AVIATION...63-KC
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page