560
FXUS64 KBRO 261141 AAA
AFDBRO
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
641 AM CDT WED MAR 26 2025
..NEW AVIATION
SHORT TERM
(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 631 AM CDT WED MAR 26 2025
KEY MESSAGES:
* ENVIRONMENTAL CONDITIONS ARE BECOMING MORE FAVORABLE FOR THE
DEVELOPMENT OF WIDESPREAD SHOWERS AND THUNDERSTORMS FOR THE
MAJORITY OF THE PERIOD.
* FLASH FLOOD WATCH HAS BEEN ISSUED FOR TONIGHT THROUGH FRIDAY
MORNING AS CONFIDENCE IN FLOODING RAINS GROWS.
* STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE TONIGHT AND THURSDAY
WITH THE MOST LIKELY HAZARDS TO INCLUDE GUSTY WINDS AND HAIL.
THE MAIN EVENT FOR THE SHORT TERM FORECAST PERIOD WILL BE THE
POTENTIAL FOR EXCESSIVE RAINFALL THAT COULD RESULT IN FLASH FLOODING
ESPECIALLY FOR THE NORTHERN RANCHLANDS. CURRENT MODEL GUIDANCE HAS
MOVED THE TIMING OF THE HEAVY RAINFALL UP TO TONIGHT.
THE MODEL SOUNDINGS SUGGEST THAT A DEEP SATURATED PROFILE WITH A
GOOD AMOUNT OF DIRECTIONAL SHEAR, MODERATE INSTABILITY, AND A
FRONTAL BOUNDARY NEARBY, THE ENVIRONMENT IS PRIMED FOR THE
DEVELOPMENT OF CONVECTIVE CELLS AND SEE STORMS TRAINING OVER THE
SAME LOCATIONS AS WELL. SOME THUNDERSTORMS THAT DEVELOP COULD
GENERATE SOME GUSTY WINDS AND HAIL AS WELL. THEN FOR THURSDAY, THERE
IS A BIT MORE UNCERTAINTY DUE TO CHANGES WITH THE CONVECTIVE
EVOLUTION AS THE MESOSCALE FACTORS ARE LIKELY TO HAVE CHANGED.
HOWEVER, MORE SYNOPTIC SCALE FACTORS WILL STILL PROVIDE A FAVORABLE
ENVIRONMENT FOR DEVELOPMENT AS A MID-LEVEL TROUGH AND SHORTWAVE MOVE
OVER THE REGION. THE MESOSCALE FACTORS WILL BE CRITICAL FOR WHAT
HAPPENS ON THURSDAY, THUS IT WILL BE IMPORTANT TO OBSERVE HOW THE
STORMS DEVELOP TONIGHT. CONSIDERING THE INTENSITY OF THE DROUGHT
THAT HAS AFFECTED DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY, THE
SOIL IS EXPECTED TO BE DRY, WHICH IN TURN MEANS THAT THE RAINFALL
WILL MOST LIKELY BECOME RUNOFF INSTEAD OF SINKING INTO THE SOIL.
WITH THE INCREASED AMOUNT OF RUNOFF LIKELY, FLASH FLOODING BECOMES
EVEN MORE LIKELY AS A RESULT. GIVEN THE HIGH SIGNALS COMING FROM THE
VARIOUS MODELS, A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE NORTHERN
RANCHLANDS STARTING TONIGHT AND GOING THROUGH FRIDAY MORNING. WITH
EXPECTED RAINFALL AMOUNTS IN THE RANGE OF 3-5 INCHES WITH LOCALLY
HEAVIER AMOUNTS UP TO 8 INCHES POSSIBLE.
WHILE THE CURRENT MODEL GUIDANCE DOES PUT A GREATER EMPHASIS FOR THE
NORTHERN RANCHLANDS WITH THIS EVENT. THAT DOES NOT MEAN THAT THERE
WILL NOT BE ANY IMPACTS FOR THE MIDDLE AND LOWER RIO GRANDE VALLEY.
THE ENVIRONMENT IS NEARLY AS FAVORABLE FOR THE DEVELOPMENT OF
SHOWERS AND THUNDERSTORMS, BUT LESS THAN WHAT THE CURRENT MODEL
GUIDANCE SUGGEST FOR THE NORTHERN RANCHLANDS. CURRENT MODEL FORECAST
PROJECTIONS HAVE RAINFALL AMOUNTS IN THE RANGE OF 2 TO 4 INCHES WITH
SOME LOCALLY HEAVIER AMOUNTS IN UP TO 6 INCHES POSSIBLE. THIS COULD
LEAD TO SOME NUISANCE FLOODING IN AREAS OF POOR DRAINAGE AND URBAN
AREAS.
THE CURRENT OUTLOOK FROM WPC HAS THE NORTHERN PORTIONS OF ZAPATA,
JIM HOGG, BROOKS, AND KENEDY COUNTIES IN A SLIGHT RISK OF EXCESSIVE
RAINFALL (LEVEL 2 OF 4), WHILE THE SOUTHERN PARTS OF THOSE COUNTIES
AND MOST OF STARR ARE IN A MARGINAL RISK (LEVEL 1 OF 4) OF EXCESSIVE
RAINFALL FOR TODAY. THEN FOR THURSDAY, WPC HAS THE NORTHERN PART OF
JIM HOGG ALONG WITH MOST OF BROOKS AND KENEDY COUNTIES IN A SLIGHT
RISK OF EXCESSIVE RAINFALL, WHILE THE REST OF DEEP SOUTH TEXAS AND
THE RIO GRANDE VALLEY IS IN A MARGINAL RISK OF EXCESSIVE RAINFALL.
IN ADDITION TO THIS, SPC HAS MOST OF THE REGION IN A MARGINAL RISK
(LEVEL 1 OF 5) OF SEVERE WEATHER EXCEPT FOR THE COASTAL REGIONS,
WHICH IS IN A GENERAL THUNDERSTORM OUTLOOK. THEN ON THURSDAY, SPC
HAS ZAPATA, JIM HOGG, BROOKS, WITH MOST OF STARR KENEDY COUNTY AND A
SLIGHT PORTION OF HIDALGO COUNTY IN A SLIGHT RISK (LEVEL 2 OF 5) FOR
SEVERE WEATHER. THE REST OF THE CWA FOR THURSDAY IN IN A MARGINAL
RISK FOR SEVERE WEATHER.
AS FOR THE TEMPERATURES FOR THE SHORT TERM PERIOD, HIGHS FOR TODAY
ARE EXPECTED TO BE IN THE 80S FOR THE REGION. THEN TONIGHT THE LOW
TEMPERATURES ARE GENERALLY EXPECTED TO BE IN THE 60S, WITH A FEW
LOCATIONS GETTING INTO THE LOWER 70S. THEN FOR THURSDAY, THE HIGH
TEMPERATURES ARE EXPECTED TO BE COOLER WITH THE INCREASED CLOUD
COVERAGE FROM THE SHOWERS AND THUNDERSTORMS, RESULTING IN HIGH
LONG TERM
(FRIDAY THROUGH NEXT WEDNESDAY)
ISSUED AT 631 AM CDT WED MAR 26 2025
- HEAVY RAINFALL THROUGH THURSDAY NIGHT.
THE ONGOING HEAVY RAIN EVENT DISCUSSED IN THE SHORT-TERM MAY
CONTINUE FOR AT LEAST ON MORE PERIOD AS THE MID TO UPPER LEVEL
TROUGH SUPPORTING THE INFLUX OF ABUNDANT DEEP MOISTURE IS SHOWN BY
THE 00Z MODEL SUITE REMAINING OVER TEXAS WITH ITS AXIS STILL ALONG
THE RIO GRANDE. 30+KTS MID-LEVEL SOUTHERLY FLOW CONTINUE TO SURGE
RICH MOISTURE OVER A STATIONARY FRONT, STRADDLING THE CRP/BRO COUNTY
WARNING AREAS. THIS SET UP TO COMBINE WITH MODEST INSTABILITY (HIGH
DEW POINTS), LIFT OVER THE FRONTAL BOUNDARY AND STEEP MID-LEVEL
LAPSE RATES CONTINUING TO ALLOW FOR ADDITIONAL DEVELOPING CONVECTIVE
CLUSTERS WHICH MAY PRODUCE ANOTHER ROUND OF HEAVY RAINFALL AND/OR
SEVERE CONVECTION (HAIL GUSTY WIND) MOSTLY THURSDAY EVENING AND
OVERNIGHT. SOME LINGERING RAIN FRIDAY MORNING BEFORE IMPROVING
CONDITIONS SPREAD WEST TO EAST AS THE MID/UPPER TROUGH AXIS TRACKS
EAST OF TEXAS. THE WEEKEND LOOKS FAIR AND WARM TO HOT AS SHORTWAVE
RIDGE TRACKS OVER THE STATE. NEXT FRONT APPROACHES MONDAY BEFORE
PULLING UP STATIONARY TUESDAY AND LIFTING NORTH WEDNESDAY. MOISTURE
WILL BE LIMITED WITH THIS FRONT WITH ONLY A SLIGHT 10-15 PERCENT
CHANCE OF RAIN EARLY NEXT WEEK.
TEMPERATURES LOOK TO START OFF NEAR TO POTENTIALLY A FEW DEGREES
BELOW NORMAL THURSDAY NIGHT AND FRIDAY WITH RAIN COOLED AIR AND
LIMITED INSOLATION. MAXIMUM TEMPERATURES WARM-UP ABOVE NORMAL (4-10
DEGREE) FOR THE WEEKEND BEFORE DROPPING BACK DOWN TO SEASONAL
AVERAGES WITH THE NEXT FRONT EARLY NEXT WEEK. MINIMUMS REMAIN ABOVE
NORMAL OVER THE WEEKEND AND THE BEGINNING OF NEXT WEEK AS WINDS
REMAIN SOUTHERLY WITH NO COLD FRONT PASSAGE.
AVIATION
(12Z TAFS)
ISSUED AT 635 AM CDT WED MAR 26 2025
MOSTLY MVFR CONDITIONS ARE EXPECTED FOR THE TAF SITES DURING THE
MORNING HOURS AND PERSISTING THROUGH MOST OF THE PERIOD. SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO BE MORE FREQUENT LATE THIS
AFTERNOON AND FOR THE REST OF THE TAF CYCLE. MOST OF THESE SHOWERS
AND THUNDERSTORMS ARE LIKELY TO BRING ABOUT IFR CEILINGS AND
VISIBILITY. THERE IS A POSSIBILITY OF HEAVY RAINFALL REDUCING
VISIBILITY TOWARDS LIFR, BUT CONFIDENCE WAS NOT HIGH ENOUGH TO
INCLUDE IN THE TAF PACKAGE.
MARINE
ISSUED AT 631 AM CDT WED MAR 26 2025
TODAY THROUGH THURSDAY...WHILE MARINE CONDITIONS ARE EXPECTED TO BE
GENERALLY FAVORABLE FOR TODAY, THE SAME CAN NOT BE SAID FOR TONIGHT
AND THURSDAY. WINDS AND SEAS ARE EXPECTED TO BECOME MORE ELEVATED
WITH SOUTHEASTERLY WINDS INCREASING TO AROUND 15 TO 18 KNOTS AND
SEAS BETWEEN 4 TO 6 FEET, THUS SMALL CRAFT EXERCISE CAUTION
CONDITIONS ARE LIKELY FOR TONIGHT AND THURSDAY. HOWEVER, A LOW END
SMALL CRAFT ADVISORY CANNOT BE RULED OUT. IN ADDITION TO THE WINDS
AND SEAS, SHOWERS AND THUNDERSTORMS ARE ALSO EXPECTED AND CAN
PRODUCE HEAVY DOWNPOURS REDUCING VISIBILITY AND LOCALLY ELEVATED
WINDS AND SEAS TONIGHT AND THURSDAY.
THURSDAY NIGHT THROUGH WEDNESDAY ADVERSE MARINE CONDITIONS MAY BE
ONGOING THURSDAY NIGHT AND FRIDAY AS SHOWERS AND THUNDERSTORMS ARE
LIKELY TO BE WIDESPREAD PRODUCING GUSTY WINDS AND ROUGH SEAS. THE
WIDESPREAD THUNDERSTORMS, MODERATE TO STRONG WINDS AND HAZARDOUS
SEAS THROUGH FRIDAY ARE DUE IN PART OF A SLOW MOVING MID-LEVEL LOW
PRESSURE TROUGH OVER TEXAS, A STATIONARY FRONT OVER THE WESTERN GULF
COMBINING WITH MODEST HIGH PRESSURE NOTED OVER THE EASTERN GULF.
ONCE THE TROUGH PASSES TO THE EAST SATURDAY HIGH PRESSURE BUILDS
OVER THE TEXAS COAST WITH A STEADY IMPROVEMENT OF MARINE CONDITIONS
WITH FAIR CONDITIONS SUNDAY THROUGH TUESDAY.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 82 71 82 68 / 50 50 50 70
HARLINGEN 85 68 83 67 / 60 60 60 70
MCALLEN 85 71 84 70 / 70 70 70 80
RIO GRANDE CITY 86 70 83 67 / 80 80 80 80
SOUTH PADRE ISLAND 76 70 76 67 / 40 50 50 70
BAYVIEW/PORT ISABEL 82 68 80 66 / 40 50 50 70
BRO WATCHES/WARNINGS/ADVISORIES
TX...FLOOD WATCH FROM THIS EVENING THROUGH FRIDAY MORNING FOR
TXZ248>251-351-451.
GM...NONE.
SHORT TERM...64-KATZ
LONG TERM....59-GB
AVIATION...64-KATZ
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