129
FXUS64 KBRO 172309 AAA
AFDBRO
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
509 PM CST TUE DEC 17 2024
..NEW AVIATION
UPDATE
ISSUED AT 935 AM CST TUE DEC 17 2024
THE LATEST RADAR IMAGERY DEPICTS AN AREA OF WIDELY SCATTERED
SHOWERS SOUTH OF THE RIO GRANDE RIVER AND GULF OF MEXICO WATERS,
TRACKING NORTHWARD TOWARD DEEP SOUTH TEXAS. ADJUSTED POP TRENDS TO
ADD IN LOW POPS FOR LATE THIS MORNING AND INTO THE AFTERNOON HOURS
FOR THE LOWER AND MID RIO GRANDE VALLEY. ISOLATED THUNDERSTORMS
CANNOT BE RULED OUT LATE THIS AFTERNOON, MAINLY ALONG AND EAST OF
THE I-69 CORRIDOR.
SHORT TERM
(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 223 PM CST TUE DEC 17 2024
KEY MESSAGES:
- CONDITIONS LOOK FAVORABLE FOR FOG DEVELOPMENT TONIGHT ACROSS
PORTIONS OF DEEP SOUTH TEXAS, WITH A MEDIUM CHANCE (40-60%) OF DENSE
FOG ACROSS PORTIONS OF THE NORTHERN RANCHLANDS AND PORTIONS OF THE
MID/UPPER RGV.
- LOW PRECIPITATION CHANCES RETURN TOMORROW AFTERNOON AND
EVENING AHEAD OF AND ALONG AN APPROACHING COLD FRONT.
- COOLER TEMPERATURES ARRIVE WEDNESDAY NIGHT IN WAKE OF THE PASSAGE
OF A COLD FRONT.
MILD AND HUMID CONDITIONS ARE EXPECTED TONIGHT ONCE AGAIN ACROSS
DEEP SOUTH TEXAS. LOW TEMPERATURES WILL FALL INTO THE 60S REGION
WIDE, WHICH IS ANYWHERE FROM 10-12 DEGREES ABOVE NORMAL FOR LOW
TEMPERATURES THIS TIME OF YEAR. THE COMBINATION OF CALM WINDS AND
THE PRESENCE OF SUFFICIENT LOW LEVEL MOISTURE CONTENT WILL RESULT IN
ANOTHER ROUND OF PATCHY TO WIDESPREAD FOG ACROSS DEEP SOUTH TEXAS.
PROBABILISTIC GUIDANCE INDICATES THERE IS A MEDIUM CHANCE (40-60%)
OF DENSE FOG (VISIBILITY LESS THAN 0.25 MILES) MAINLY ALONG/EAST OF
US-281 AND ALONG/WEST OF I-69 BETWEEN 3 AM AND 9 AM WEDNESDAY
MORNING. HOWEVER, GIVEN THE RECENT RAINFALL FROM TUESDAY AFTERNOON
ACROSS THE LOWER AND MID RGV, POCKETS OF DENSE FOG CANNOT BE RULED
OUT CLOSER TO THE IMMEDIATE COAST TONIGHT AS WELL. WE'LL HAVE TO
KEEP AN EYE ON CLOUD COVER TONIGHT, WHICH WOULD HINDER EFFICIENT
PROCESSES FOR RADIATIONAL FOG DEVELOPMENT. FOR NOW, WE'LL HOLD OFF
ON ISSUING A DENSE FOG ADVISORY AND CONTINUE TO MONITOR TRENDS OVER
THE NEXT SEVERAL HOURS. REGARDLESS OF ANY DENSE FOG DEVELOPMENT
TONIGHT, GUIDANCE INDICATES VISIBILITY WILL FALL ANYWHERE FROM 1-3
MILES AFTER 3-4 AM WEDNESDAY ACROSS MOST OF DEEP SOUTH TEXAS.
ANY FOG AND/OR LOW CLOUDS WILL QUICKLY DISSIPATE BY EARLY WEDNESDAY
MORNING, MAKING WAY FOR ANOTHER WARM DECEMBER DAY ACROSS THE REGION.
FORTUNATELY, A COLD FRONT WILL BE SWEEPING ACROSS THE NORTHERN HALF
OF TEXAS BY WEDNESDAY MORNING AND SHOULD ARRIVE BY LATE WEDNESDAY
AFTERNOON OR EARLY WEDNESDAY EVENING. AHEAD OF THE COLD FRONT,
PERSISTENT LOW LEVEL SOUTHERLY FLOW MAY RESULT IN WARM-AIR ADVECTION
SHOWERS ACROSS PORTIONS OF THE REGION LATE WEDNESDAY MORNING INTO
EARLY WEDNESDAY AFTERNOON. ADDITIONALLY, HIGH RES GUIDANCE INDICATES
THAT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAY DEVELOP
ALONG THE COLD FRONT LATE WEDNESDAY AFTERNOON INTO THE EARLY EVENING
HOURS AS IT TRACKS ACROSS DEEP SOUTH TEXAS. THE MAIN THREATS WITH
ANY THUNDERSTORMS WILL BE BRIEF HEAVY RAIN, GUSTY WINDS, AND
LIGHTNING. OTHERWISE, HIGH TEMPERATURES WILL WARM INTO THE MID 80S
REGION WIDE.
COLD AIR ADVECTION WILL FILTER IN WEDNESDAY NIGHT IN WAKE OF THE
PASSAGE OF THE COLD FRONT, AND NOTABLY COOLER LOW TEMPERATURES ARE
EXPECTED. LOW TEMPERATURES WILL RANGE FROM THE UPPER 40S ACROSS THE
NORTHERN RANCHLANDS TO UPPER 50S ACROSS THE RIO GRANDE VALLEY. THIS
IS STILL SLIGHTLY ABOVE NORMAL FOR MID DECEMBER SEASONAL NORMALS,
BUT AT LEAST MUCH CLOSER TO NORMAL FOR THIS TIME OF YEAR.
LONG TERM
(THURSDAY THROUGH NEXT TUESDAY)
ISSUED AT 223 PM CST TUE DEC 17 2024
THE LONG-TERM FORECAST PERIOD WILL FEATURE MAINLY RAIN-FREE
CONDITIONS AND TEMPERATURES NEAR SEASONABLE LEVELS. WE START OF THE
EXTENDED ON THURSDAY, WHERE ON THE BACKSIDE OF A COLD FRONT, A COOL
AND DRY AIRMASS REGIME WILL FULLY BE IN PLACE OVER THE REGION.
THURSDAY WILL BE THE COOLEST DAY OF THE PERIOD. HIGH TEMPERATURES
WILL STRUGGLE TO MAKE IT OUT OF THE 60S IN SOME SPOTS WHILE OTHERS
REACH INTO THE LOW 70S AMID CONTINUED COOL AIR ADVECTION (CAA) VIA
NORTHERLY SFC WINDS. TEMPERATURE ANOMALIES WILL TRY TO MODERATE
SLIGHTLY TO CLOSER TO SEASONABLE LEVELS FRIDAY THROUGH SUNDAY.
A WEAKENING COLD FRONT IS EXPECTED TO APPROACH THE AREA ON SUNDAY AS
A LARGE 1036 MB SFC HIGH BUILDS OVER THE EASTERN CONUS. GIVEN THE
WEAK COOL FRONTAL BOUNDARY NEARBY, THE AREA BEING ON THE EASTERN
FLANK OF A STRONG WESTERN U.S. RIDGE (HIGHER GEOPOTENTIAL HEIGHTS
OVERHEAD), AND THE AFOREMENTIONED SFC HIGH PASSING TO OUR
EAST/NORTHEAST (GIVING WAY TO AN INCREASED SOUTHEASTERLY WIND
COMPONENT), AN AIRMASS CHANGE IS NOT ANTICIPATED TO THE COOLER SIDE
AT THIS TIME. IN FACT, WE COULD SEE TEMPERATURES INCREASE TO WARMER
THAN NORMAL LEVELS DURING THE EARLY PARTS OF NEXT WEEK. HIGH
TEMPERATURES ON MONDAY AND TUESDAY ARE EXPECTED TO BE IN THE UPPER
70S TO LOWER 80S.
OVERNIGHT LOWS THURSDAY NIGHT THROUGH SATURDAY NIGHT ARE EXPECTED TO
MAINLY BE IN THE 50S. SUNDAY NIGHT THROUGH TUESDAY NIGHT, OVERNIGHT
LOWS ARE EXPECTED TO INCREASE INTO THE 50S/60S.
AVIATION
(00Z TAFS)
ISSUED AT 503 PM CST TUE DEC 17 2024
A FEW ISOLATED SHOWERS CONTINUE TO AFFECT PORTIONS OF DEEP SOUTH
TEXAS BUT WILL QUICKLY DISSIPATE OVER THE NEXT HOUR OR TWO. VFR
CONDITIONS WILL PREVAIL THIS EVENING AT ALL AERODROMES. FOG IS
POSSIBLE LATER TONIGHT INTO WEDNESDAY MORNING, ESPECIALLY ACROSS
THE NORTHERN RANCHLANDS, WITH PATCHY FOG POSSIBLE FARTHER SOUTH.
BRO WILL FALL TO MVFR OVERNIGHT BEFORE RETURNING TO VFR BY MID
MORNING. HRL AND MFE WILL HAVE A BETTER CHANCE OF SEEING SOME
PATCHY FOG WITH LOWERED CEILINGS AND VISIBILITY WITH IFR
CONDITIONS LIKELY AFTER MIDNIGHT, AND MFE LIKELY FALLING TO LIFR,
ANY PATCHY FOG THAT DEVELOPS OR LOWERED CEILINGS WILL DISSIPATE
WITH A RETURN TO VFR MY MID TO LATE WEDNESDAY MORNING.
MARINE
ISSUED AT 223 PM CST TUE DEC 17 2024
TONIGHT THROUGH WEDNESDAY NIGHT...GENERALLY FAVORABLE MARINE
CONDITIONS WILL PREVAIL THROUGH WEDNESDAY AFTERNOON WITH LIGHT
SOUTHERLY WINDS AND LOW TO MODERATE SEAS. A COLD FRONT WILL APPROACH
LATE WEDNESDAY AFTERNOON AND EVENING, WHICH WILL RESULT IN NORTHERLY
WINDS NEAR OR JUST BELOW 15 TO 20 KNOTS WEDNESDAY NIGHT OVER THE
NORTHERN GULF WATERS. SMALL CRAFT SHOULD EXERCISE CAUTION CONDITIONS
MAY BE REACHED LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. SEAS WILL
RESPOND AND INCREASE TO AROUND 4-5 FEET WEDNESDAY NIGHT.
THURSDAY THROUGH TUESDAY NIGHT...LIGHT TO MODERATE WINDS
AND LOW TO MODERATE SEAS ARE EXPECTED TO PREVAIL THROUGH TUESDAY
NIGHT.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 67 80 58 69 / 0 20 20 0
HARLINGEN 64 81 54 69 / 0 20 20 0
MCALLEN 68 84 57 71 / 0 30 30 0
RIO GRANDE CITY 65 81 56 69 / 0 30 40 0
SOUTH PADRE ISLAND 71 75 62 66 / 0 10 10 0
BAYVIEW/PORT ISABEL 66 78 56 67 / 0 20 10 0
BRO WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...NONE.
SHORT TERM...22
LONG TERM....23
AVIATION...68
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