Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 262353
AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
553 PM CST FRI DEC 26 2014

.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

&&

.AVIATION...WINDS WILL DECREASE TO AROUND 10 KNOTS AFTER SUNSET
WITH CLOUD COVER SLOWLY INCREASING THIS EVENING. CEILINGS WILL
BECOME MVFR AROUND 09Z AND SHOULD REMAIN THERE THROUGH EARLY
SATURDAY MORNING...BUT CANNOT RULE OUT A FEW HOURS OF BORDERLINE
IFR CEILINGS AROUND DAYBREAK. ENOUGH LOW LEVEL MOISTURE WILL BE
PRESENT FOR SOME FOG TO DEVELOP OVERNIGHT BUT WINDS SHOULD REMAIN
ELEVATED ENOUGH TO PRECLUDE WIDESPREAD DENSE FOG FROM FORMING.

&&

.PREV DISCUSSION... /ISSUED 239 PM CST FRI DEC 26 2014/

SHORT TERM /NOW THROUGH SATURDAY NIGHT/...HIGHLY AMPLIFIED
PATTERN WILL LEAD TO BIG CHANGES AT THE END OF THE SHORT TERM
PERIOD AS THE LARGE H5 TROUGH SWEEPS ACROSS THE CENTRAL US.
STARTING WITH TONIGHT...LLVL SOUTHEAST WINDS HAVE PULLED MORE
MOISTURE INTO THE LOWER LEVELS. INVERSION CONTINUE AT 4000
FT...AND SFC WINDS REMAIN AROUND 01 KNOTS OVERNIGHT. THESE TWO
FACTORS WILL KEEP FOG FROM GETTING DENSE OVERNIGHT. TOMORROW...A
PREFRONTAL TROUGH SLIDES ACROSS THE REGION...BRINGING LIGHTER
SOUTHERLY FLOW ALONG THE COAST AND L/V WINDS FURTHER INLAND.
SLIGHT SOUTHWESTERLY FLOW WILL BRING TEMPS UP A BIT FOR THE MID
AND LOWER VALLEY...WHICH WILL REACH NEAR 80 DEGREES. THE NEXT COLD
FRONT WILL RACE THROUGH DEEP SOUTH TEXAS AFTER SUNSET TOMORROW...
WITH NORTH WINDS OF 15 TO 20KTS. GOOD FORCING ALONG THE FRONT WILL
BRING A CHANCE FOR SHOWERS SATURDAY NIGHT...BUT THE MAIN FORCING
WILL BE JUST BEHIND THE FRONTAL PASSAGE...SO HAVE LIMITED ANY
THUNDER MENTION TO OFFSHORE ONLY. TEMPERATURES WILL FALL QUICKLY
BEHIND THE FRONT...WITH SATURDAY NIGHT LOWS REACHING THE MID 40S.

LONG TERM /SUNDAY THROUGH THURSDAY/...
DRY AIR AND WEAK HIGH PRESSURE WILL FILTER IN ON SUNDAY...
RESULTING IN A TRANQUIL DAY. HIGH TEMPS WILL BE DECIDEDLY COOLER
ON SUNDAY... HOWEVER...AVERAGING 15 TO 20 DEGREES COOLER THAN ON
SATURDAY BEFORE THE FRONT MOVED THROUGH...AND WILL BE MAINLY IN
THE 50S. THERE WILL BE SOME CLEARING LATE SUNDAY THROUGH MONDAY
MORNING...AND LOW TEMPS SUNDAY NIGHT WILL BE IN THE 40S FOR MOST
AREAS. SOME UPPER 30S MAY BE REALIZED ACROSS THE NORTHERN RANCH
LANDS AND BRUSH COUNTRY.

WINDS WILL VEER TO EAST SUNDAY NIGHT INTO MONDAY AS SURFACE HIGH
PRESSURE SHIFTS EAST...BRINGING SOME GULF MOISTURE AND INCREASED
CLOUDINESS BACK INTO THE AREA FROM EAST TO WEST...BUT NO ACTIVE
WEATHER. HIGH TEMPS MONDAY WILL REBOUND INTO THE 60S AND FAIRLY
CLOSE TO NORMAL...WITH LOW TEMPS MONDAY NIGHT RECOVERING INTO THE
UPPER 40S NORTH...AND UPPER 50S AROUND THE LOWER VALLEY. THE
LATEST GUIDANCE HINTS AT SOMEWHAT LOWER TEMPS MONDAY NIGHT BASED
ON LIGHT WINDS AND CLEARING SKIES...AND THIS MIGHT BE AN AREA THAT
COULD BE REVISITED BY SUBSEQUENT SHIFTS.

THE NEXT FRONT WILL PUSH SOUTH TUESDAY...POWERED BY 1050 MB OR
MORE HIGH PRESSURE SPILLING OUT OF THE CANADIAN ROCKIES INTO THE
NORTHERN AND THEN CENTRAL HIGH PLAINS. EAST NORTHEAST WINDS WILL
ARRIVE IN DEEP SOUTH TEXAS AND THE RGV TUESDAY...KEEPING HIGH
TEMPS NEAR NORMAL FOR THE DAY AROUND THE LOWER VALLEY...BUT
PERHAPS A BIT BELOW NORMAL ACROSS THE RANCH LANDS. A MID LEVEL LOW
OVER THE CENTRAL WEST COAST IS GOING TO CAPTURE SOME OF THE
SOUTHERN BRANCH JET ENERGY WHILE THE ROCKIES SPLIT THE COLD AIR
MOVING SOUTH...DIVERTING SOME INTO TEXAS AND ANOTHER PORTION WEST
OF THE ROCKIES IVO THE GREAT BASIN. LOW TEMPERATURES WILL TREND
DOWN TUESDAY NIGHT UNDER MSTLY CLDY SKIES AND WITH AN INCREASING
THREAT OF OVERRUNNING LIGHT RAIN. LOW TEMPS IN THE 40S AND 50S
WILL BE THE RULE WITH MDT TO BREEZY NORTH WINDS POSSIBLY PRODUCING
SOME UPPER 30S FEELS LIKE TEMPS ACROSS THE RANCH LANDS.

BY WEDNESDAY STRONG HIGH PRESSURE WILL BE SITUATED OVER NORTH TEXAS
WITH MODERATE NORTH WINDS FILTERING INTO DEEP SOUTH TEXAS AND THE
RGV...WITH CLOUDY SKIES AND HIGH TEMPERATURES RANGING FROM THE 40S
OVER THE NORTHERN RANCH LANDS AND BRUSH COUNTRY TO THE 50S ACROSS
THE LWR VALLEY. TEMPS WEDNESDAY WILL NOT INCREASE MUCH FROM TUESDAY
NIGHT. OVERRUNNING WITH LIGHT PRECIP ACCUMULATION WILL CONTINUE
WEDNESDAY NIGHT UNDER MOSTLY CLOUDY TO CLOUDY SKIES AND LIGHT WINDS
AS HIGH PRESSURE SETTLES OVER THE AREA. LOW TEMPERATURES WILL BE
MAINLY IN THE 40S WITH SOME UPPER 30S POSSIBLE ACROSS THE NORTHERN
TIER. A COASTAL TROUGH OR WEAK SURFACE LOW MAY SET UP AT THIS TIME
WHICH WOULD HELP MAINTAIN THE CLOUDY...COLDER...DRIZZLY WEATHER
WEDNESDAY NIGHT INTO THURSDAY.

MARINE...
NOW THROUGH SATURDAY NIGHT...SMALL CRAFT ADVISORIES WILL BE
EXTENDED SLIGHTLY THIS EVENING AS SEAS CONTINUE TO HOVER IN THE 7
TO 8 FOOT RANGE. WITH THE FRONT APPROACHING TOMORROW AND THE
PREFRONTAL TROUGH MOVING IN FROM THE WEST...WINDS WILL RELAX
OFFSHORE TOMORROW TO AROUND 10 KNOTS. THE FRONT IS CURRENTLY
FORECAST TO ARRIVE GENERALLY BETWEEN 9 PM AND MIDNIGHT SATURDAY
NIGHT. WINDS ALONG THE FRONT WILL QUICKLY SWITCH TO THE NORTH AND
INCREASE TO 20 TO 25 KNOTS. DO NOT FORESEE ANY GUSTS APPROACHING
GALE CRITERIA...SO ONLY SMALL CRAFT ADVISORIES WILL BE NEEDED.
SEAS WILL JUMP BACK UP TO 6 TO 7 FEET OFFSHORE LATE SATURDAY
NIGHT.

SUNDAY THROUGH SATURDAY...A COLD FRONT WILL PUSH OFFSHORE
SATURDAY NIGHT...SHIFTING WINDS TO NORTH NORTHWEST. WINDS WILL TOP
OUT AT AROUND 25 KNOTS WITH GUSTS TO 30 KNOTS MID SUNDAY...WITH
SMALL CRAFT ADVISORY CONDITIONS LIKELY. THE WIND WILL DECREASE TO
LIGHT NORTH TO NORTHEAST SUNDAY NIGHT AS HIGH PRESSURE SPREADS
OVER THE AREA. SEAS WILL BUILD TO AROUND SEVEN FEET ON THE GULF
SUNDAY. ISOLATED TO SCT SHOWERS AND AN ISOLATED THUNDERSTORM OR
TWO WILL BE POSSIBLE LATE SATURDAY NIGHT TO EARLY SUNDAY MORNING
AS THE FRONT PUSHES OFFSHORE. WINDS WILL REMAIN LIGHT TO MDT FROM
THE EAST MONDAY...BUT WINDS WILL BACK TO NORTHEAST AND BEGIN TO
INCREASE MONDAY NIGHT AS COLDER AIR PUSHES SOUTH AND OUT INTO THE
NORTHWEST GULF. MDT TO BREEZY EAST NORTHEAST WINDS WILL DEVELOP
NEXT TUESDAY IN THE WAKE OF A HIGH PRESSURE AIR MASS MOVING OUT
OVER THE GULF. MID DAY TUESDAY IS A REASONABLE TIME TO DELINEATE A
FRONTAL PASSAGE...WITH LOWERING CLOUD DECKS AND INCREASING CHANCES
FOR LIGHT RAIN THEREAFTER. SMALL CRAFT ADVISORY CONDITIONS APPEAR
VERY LIKELY LATE TUESDAY ONWARD.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR GMZ150-155-
     170-175.

&&

$$

THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV

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