348
FXUS64 KBRO 290542 AAA
AFDBRO
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1242 AM CDT TUE SEP 29 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 1235 AM CDT TUE SEP 29 2026
- WIDESPREAD MAJOR (LEVEL 3 OUT OF 4) HEAT RISK WITH POCKETS OF
EXTREME (LEVEL 4 OF 4) HEAT RISK TO CONTINUE ACROSS THE REGION
THROUGH THURSDAY.
- CONFIDENCE IS INCREASING ON A SIGNIFICANT WEATHER PATTERN
CHANGE TOWARDS COOLER AND WETTER CONDITIONS LATER THIS WEEK;
THIS INCLUDES A MULTI-DAY HEAVY RAIN AND FLASH FLOOD POTENTIAL
THURSDAY INTO THE WEEKEND.
- THE WEATHER PREDICTION CENTER (WPC) HAS ALL OF DEEP SOUTH TEXAS
UNDER A SLIGHT (LEVEL 2 OF 4) RISK FOR EXCESSIVE RAINFALL FOR
THURSDAY, AND A MARGINAL (LEVEL 1 OF 4) TO SLIGHT RISK FRIDAY.
DISCUSSION
ISSUED AT 1103 PM CDT MON SEP 28 2026
AN UPPER LEVEL TROUGH OVER THE SOUTHWEST WILL INGEST DEEP
TROPICAL MOISTURE FROM THE PACIFIC EARLY THIS WEEK. AS THE TROUGH
MOVES FURTHER EAST, AN ACCOMPANYING COLD FRONT IS FORECAST TO PUSH
INTO CENTRAL TEXAS, BEFORE LIKELY STALLING MID-WEEK. LOCALLY,
CONTINUED SOUTHEASTERLY LOW LEVEL FLOW WILL ADVECT ADDITIONAL WARM
AND HUMID AIR FROM THE GULF ACROSS DEEP SOUTH TEXAS. IN THE SHORT
TERM, THIS WILL CONTINUE TO SUPPORT DAILY HEAT CONCERNS WITH
AFTERNOON HEAT INDEX VALUES RANGING FROM 105-115. HEAT ADVISORIES
MAY BE NEEDED DAILY THROUGH THURSDAY.
AS THE TROUGH CONTINUES MOVING EASTWARD, INCREASED FORCING ACROSS
EASTERN TEXAS, COMBINED WITH PWATS RANGING FROM 2-2.5 INCHES WILL
LIKELY RESULT IN WIDESPREAD RAINFALL ACROSS DEEP SOUTH TEXAS
THURSDAY AFTERNOON INTO THE WEEKEND. THE HEAVIEST RAINFALL IS MOST
LIKELY TO OCCUR THURSDAY AND FRIDAY, WITH PROBABILISTIC MODELS
SUPPORTING 48 HOUR RAINFALL ACCUMULATIONS FROM 7 AM THURSDAY
THROUGH 7 AM SATURDAY RANGING FROM 0.5-3 INCHES ACROSS THE MID AND
LOWER RIO GRANDE VALLEY AND 2 TO 4 INCHES FURTHER WEST. THE
WEATHER PREDICTION CENTER HAS ALL OF DEEP SOUTH TEXAS IN A SLIGHT
RISK (LEVEL 2 OF 4) FOR EXCESSIVE RAINFALL THURSDAY, AND A
MARGINAL RISK (LEVEL 1 OF 4) FOR EXCESSIVE RAINFALL ACROSS THE
COASTAL COUNTIES, WITH ANOTHER SLIGHT RISK OVER INLAND COUNTIES
FRIDAY.
THE BULK OF THE MODEL GUIDANCE SUGGEST THAT THE STALLED FRONTAL
BOUNDARY MAY RESUME ITS SOUTHEASTWARD MOTION FRIDAY, BRINGING THE
COLD FRONT THROUGH DEEP SOUTH TEXAS FRIDAY AFTERNOON INTO FRIDAY
EVENING. LIGHT NORTHERLY SURFACE FLOW BEHIND THE FRONT COULD
SUPPORT COOLER TEMPERATURES OVER THE WEEKEND, WITH HIGH
TEMPERATURES IN THE MID 80S TO LOW 90S AND OVERNIGHT LOWS IN THE
LOW TO MID 70S. EASTERLY TO SOUTHEASTERLY MID LEVEL FLOW WILL
LIKELY CONTINUE THROUGH THE WEEKEND, RESULTING IN AN OVERRUNNING
PATTERN THAT WILL SUPPORT OVERCAST SKIES WITH GENERALLY LIGHT
RAIN.
AVIATION
(06Z TAFS)
ISSUED AT 1235 AM CDT TUE SEP 29 2026
LIGHT SOUTHEAST WINDS AND MOSTLY CLEAR SKIES PREVAIL ACROSS DEEP
SOUTH TEXAS EARLY THIS MORNING. LIGHT SOUTHEAST WINDS OVERNIGHT
WILL INCREASE TO 10 TO 15 KTS WITH GUSTS AROUND 20 KTS LATER THIS
MORNING INTO THE AFTERNOON. THERE IS A LOW (10-20%) CHANCE FOR
ISOLATED CONVECTION ALONG THE SEA BREEZE TODAY. WINDS ARE FORECAST
TO DECREASE LATER THIS EVENING. VFR CONDITIONS ARE EXPECTED TO
CONTINUE FOR THE NEXT 24 HOURS.
MARINE
ISSUED AT 1103 PM CDT MON SEP 28 2026
WINDS AND SEAS ALONG THE LOWER TEXAS COAST ARE FORECAST TO BEGIN
INCREASING TUESDAY WITH ADDITIONAL INCREASES ANTICIPATED MID WEEK
AS PRESSURE GRADIENTS TIGHTEN AHEAD OF AN APPROACHING COLD FRONT.
THIS WILL LIKELY LEAD TO ADVERSE CONDITIONS ON THE GULF AND LAGUNA
MADRE WITH HAZARDOUS CONDITIONS POSSIBLE LATER IN THE WEEK. SMALL
CRAFT SHOULD EXERCISE CAUTION HEADLINES WILL LIKELY BE NEEDED
BEGINNING TUESDAY, AND SMALL CRAFT ADVISORIES MAY BE NEEDED
THURSDAY AND FRIDAY.
THE COLD FRONT IS FORECAST TO MOVE THROUGH THE AREA FRIDAY
EVENING, WITH LIGHT NORTHEASTERLY WINDS BEHIND THE FRONT
SUPPORTING LOWER SEAS THROUGH THE WEEKEND.
RAIN CHANCES ARE FORECAST TO INCREASE THURSDAY AFTERNOON, WITH
WIDESPREAD RAINFALL LIKELY THROUGH THE WEEKEND
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 96 82 97 83 / 30 10 0 10
HARLINGEN 100 78 101 79 / 20 10 0 0
MCALLEN 102 82 103 83 / 10 10 10 0
RIO GRANDE CITY 103 80 104 80 / 0 0 0 10
SOUTH PADRE ISLAND 90 83 90 84 / 30 10 10 10
BAYVIEW/PORT ISABEL 95 80 96 80 / 30 10 10 0
BRO WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...NONE.
SHORT TERM...60-BE
LONG TERM....60-BE
AVIATION...63-KC
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