Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 260522 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1122 PM CST THU DEC 25 2014

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

.AVIATION...AN OVERCAST DECK OF CLOUDINESS AROUND 3000 TO 4000 FEET
HAS QUICKLY SPREAD FROM THE SOUTHWEST TO NORTHEAST OVER SOUTHWEST
TX. THIS CLOUDINESS IS LIKELY TO PERSIST UNTIL AT LEAST AROUND
SUNRISE FRIDAY. LLJ OF 35 TO 40 KNOT WEST HARLINGEN WILL STRENGTHEN
OVERNIGHT WITH LOW POTENTIAL FOR LLWS AS THE WINDS WILL MIX A BIT
AT THE SURFACE AND REMAIN AT AROUND 15 KNOTS. SOUTH TO SOUTHEAST
WINDS WILL PREVAIL INTO TOMORROW PICKING UP WITH DAYTIME HEATING
WITH CLOUDS PREVAILING BUT CIGS WILL BE VFR. AFTER SUNSET THE
GRADIENT WEAKENS ALLOWING FOR WINDS TO SUBSIDE.
&&

.PREV DISCUSSION... /ISSUED 559 PM CST THU DEC 25 2014/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...TONIGHT INTO FRIDAY AN UPPER TROUGH DEPENDS AND
MOVES ACROSS THE FOUR CORNERS REGION STRENGTHENING THE UPPER
LEVEL GRADIENT ACROSS SOUTH TX. THE LLJ BEGINS TO STRENGTHEN
OVERNIGHT WITH 35 TO 40 KNOTS WEST OF KHRL. AT THIS TIME...NOT
EXPECTING LOW LEVEL WIND SHEAR AS SURFACE WINDS REMAIN CLOSE TO
10 TO 12 KNOTS THROUGH THE NIGHT. IF WINDS LOWER MORE THAN IT
IS EXPECTED...THERE IS A POTENTIAL FOR LLWS ESPECIALLY OVER KMFE
WITH SOUTH WINDS OF 35 TO 40 KNOTS AND TAF WILL HAVE TO BE
AMENDED. WITH THIS SE FLOW...CLOUD COVER WILL ALSO BE ON THE
INCREASE WITH MVFR CONDITIONS CLOSER TO MIDNIGHT THROUGH EARLY
MORNING HOURS. INVERSION SHOULD KEEP THE CLOUD DECK NO LOWER THAN
3000 FEET. BY 15Z THE LLJ SHIFTS E WITH 35 TO 40 KNOT WIND OVER
KBRO AND ALONG THE COAST. THIS WILL KEEP BREEZE CONDITIONS
ESPECIALLY OVER KBRO WITH GUSTS UP TO 28 KNOTS POSSIBLE. IT WILL
WEAKEN INTO THE EVENING AS THE GRADIENT WEAKENS AT THE SURFACE AND
LLJ WEAKENS AND LIFTS NE.

PREV DISCUSSION... /ISSUED 242 PM CST THU DEC 25 2014/

SHORT TERM /NOW THROUGH FRIDAY NIGHT/...

NOW AND TONIGHT...UPPER LOW PRESSURE TROUGH BECOMING ESTABLISHED
OVER THE INTERMOUNTAIN WEST AND 4 CORNERS AREA. SURFACE PRESSURES
CONTINUE TO LOWER OVER THE SOUTHERN PLAINS INCREASING THE SOUTHERLY
FLOW OVER DEEP SOUTH TEXAS. GUSTS OF 35 MPH ARE COMMON PLACE THIS
AFTERNOON ALONG THE 69E CORRIDOR. LOW LEVEL JET OF 30-40+KNOTS
DEVELOPS OVERNIGHT WHICH WILL KEEP WINDS SOMEWHAT BREEZY TONIGHT.
THE MAIN IMPACT WITH THE SOUTH WINDS THOUGH WILL BE MUCH WARMER
TEMPERATURES. EXPECTING AT LEAST 15 TO 20 DEGREE DIFFERENCE IN
OVERNIGHT MINIMUMS FROM THIS MORNING. INSTEAD OF LOW TO UPPER 30S
WE WILL LIKELY SEE LOW TO MID 50S NORTH AND WEST AND NEAR 60 IN THE
LOWER VALLEY AND ALONG THE COAST. LOW LEVEL MOISTURE IS SLOW TO
RETURN BUT DEW POINTS ARE INCHING UPWARD. INITIALLY A VEIL OF HIGH
CLOUDS WILL BE REPLACED BY THE MORE TYPICAL LOW LEVEL CLOUDS BY
FRIDAY MORNING.

FRIDAY AND FRIDAY NIGHT...THE SOUTHERLY FLOW WILL BE WELL
ESTABLISHED FRIDAY AS THE LLJ MOVES OVERHEAD IN THE MORNING BEFORE
TRACKING EAST OVER THE GULF THROUGH THE DAY. WINDS BECOME BREEZY TO
WINDY INTO THE EARLY AFTERNOON BEFORE RELAXING LATE IN THE DAY.
TEMPERATURES GUIDANCE INDICATING ALL  AREAS IN THE MID TO UPPER 70S
WITH A FEW SPOTS APPROACHING 80. CURRENT FORECAST REFLECTS THIS AND
SEE NO REASON TO DEVIATE. THE CONTINUED MOISTURE RETURN THROUGH
FRIDAY WILL NOT BE DEEP ENOUGH TO REQUIRE ANY MENTION OF POPS AT
THIS TIME BUT LOWER CLOUD COVER TO INCREASE.

LONG TERM /SATURDAY THROUGH WEDNESDAY/...SOUTH SOUTHEAST SURFACE
RETURN FLOW AND SOUTHWEST CAPPING FLOW ALOFT WILL HELP TEMPERATURES
CLIMB ABOVE NORMAL SATURDAY...WELL INTO THE 70S ESPECIALLY FOR THE
LOWER VALLEY. A COLD FRONT WILL BE OVER CENTRAL TEXAS AND ON THE WAY
SOUTH HOWEVER. WINDS WILL SWITCH TO NORTH ACROSS THE RANCH LANDS BY
EARLY AFTERNOON...POSSIBLY LIMITING HIGH TEMPERATURES FOR THE DAY.
THE FRONT WILL BE THROUGH BY LATE AFTERNOON OR EARLY EVENING. MOST
OF THE ACTIVE WEATHER LOOKS LIKE IT WILL OCCUR OVER THE MARINE AREAS
AS THE FRONT MOVES OFFSHORE. LOW TEMPERATURES SATURDAY NIGHT WILL
RANGE FROM THE MID 40S ACROSS THE RANCH LANDS TO THE MID 50S NEAR
THE COAST.

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. TEMPERATURES WILL CHECK IN NEAR 60 ACROSS
THE RANCH LANDS TO NEAR 70 IN THE LOWER VALLEY. THERE WILL BE SOME
CLEARING THROUGH MONDAY MORNING...AND LOW TEMPERATURES 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
50S AND NEAR 60 AROUND THE LOWER VALLEY...ABOVE NORMAL.

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. NORTHEAST WINDS WILL ARRIVE IN DEEP
SOUTH TEXAS AND THE RGV TUESDAY AFTERNOON...KEEPING HIGH TEMPS NEAR
NORMAL FOR THE DAY. 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. LOW TEMPERATURES WILL TREND
DOWN TUESDAY NIGHT UNDER MOSTLY CLOUDY SKIES AND WITH AN INCREASING
THREAT OF OVER RUNNING LIGHT RAIN. AS THE TIGHTEST GRADIENT WILL
OCCUR TUESDAY NIGHT...LOOK FOR BREEZY NORTH WINDS WITH FEELS LIKE
TEMPERATURES OVER THE RANCH LANDS IN THE MID 30S.

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 50 OVER
THE NORTHERN RANCH LANDS AND BRUSH COUNTRY TO NEAR 60 ACROSS THE LWR
VALLEY. 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.

MARINE...

NOW THROUGH FRIDAY NIGHT...SMALL CRAFT ADVISORIES FOR THE OFFSHORE
WATERS ARE NOW IN EFFECT UNTIL NOON FRIDAY. PRESSURE GRADIENT TO
INTENSIFY OVERNIGHT AS SURFACE LOW PRESSURE DEVELOPS OVER THE
CENTRAL AND SOUTHERN PLAINS. THE GRADIENT STEADILY WEAKENS IN THE
LATE MORNING AND AFTERNOON HOURS WITH BOTH AND WIND AND SEAS
LOWERING THROUGH FRIDAY NIGHT AS THE STORM SYSTEM LIFTS NORTHEAST
AND COLD FRONT MOVES INTO CENTRAL TEXAS.

SATURDAY THROUGH MONDAY...MODERATE SOUTH SOUTHEAST WINDS AND MDT
SEAS TO START SATURDAY...WITH A COLD FRONT MOVING INTO CENTRAL
TEXAS. WINDS WILL FURTHER DECREASE SATURDAY AFTERNOON...BUT BY
AROUND MIDNIGHT THE COLD FRONT WILL PUSH OFFSHORE...SHIFTING WINDS
TO NORTH OR NORTH NORTHWEST. WINDS WILL TOP OUT AT AROUND 20 KNOTS
SUNDAY MORNING...WITH BORDERLINE SMALL CRAFT ADVISORY CONDITIONS...
WITH THOSE WINDS DECREASING TO MODERATE NORTHEAST SUNDAY NIGHT AS
HIGH PRESSURE SPREADS OVER THE AREA. SEAS WILL ONLY BUILD TO BETWEEN
4 AND 6 FEET SUNDAY DUE TO THE RELATIVELY SHORT DURATION OF POST
FRONTAL NORTH WINDS. ISOLATED TO SCATTERED SHOWERS AND AN ISOLATED
THUNDERSTORM OR TWO MAY ACCOMPANY THE FRONT LATE SATURDAY NIGHT.
&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL NOON CST FRIDAY FOR GMZ150-155-170-
     175.
&&

$$

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HTTP://WEATHER.GOV/RGV




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