000
FXUS64 KBRO 052359 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
559 PM CST THU DEC 5 2013

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

&&

.AVIATION...A STRONG COLD FRONT CURRENTLY MOVING ACROSS THE
NORTHERN RANCHLANDS OF DEEP SOUTH TEXAS IS EXPECTED TO MOVE
THROUGH THE RIO GRANDE VALLEY BETWEEN 02Z AND 03Z. WINDS WILL
QUICKLY SHIFT TO THE NORTH AND BECOME GUSTY AFTER THE FRONTAL
PASSAGE. LOW CLOUDS...BREEZY CONDITIONS ALONG WITH LIGHT
RAIN/DRIZZLE WILL PERSIST THROUGH THE FORECAST PERIOD. MVFR/IFR
CEILINGS CAN BE EXPECTED AT ALL TAF SITES FOR THE NEXT 24 HOURS.

&&

.PREV DISCUSSION... /ISSUED 159 PM CST THU DEC 5 2013/

SHORT TERM /NOW THROUGH FRIDAY NIGHT/... TROUGH OVER THE WESTERN
PORTION OF THE CWA WILL PUSH SOUTH A STRONG COLD FRONT ACROSS THE
CWA LATE TONIGHT INTO EARLY FRIDAY MORNING. FRONT WILL ENTER THE
RANCH LAND AND BRUSH COUNTRY THIS EVENING THEN SLOW DOWN AS THE
SYSTEM BUMPS AGAINST THE MID LEVEL HIGH AND SHORTWAVE ENERGY
ROUNDS THE BASE OF THE TROUGH. ONCE THE TROUGH MOVES ACROSS THE
AREA THIS WILL HELP PUSH THE FRONT DOWN SOUTH OF THE AREA AND
ALLOW RIDGING FROM A 1042MB HIGH PRESSURE OVER THE NORTHERN PLAINS
TO FULLY INFILTRATE THE AREA FRIDAY. EXPECT THE NORTH TO NORTHEAST
WINDS BEGINNING EARLY BEFORE MIDNIGHT BECOMING MORE NORTHERLY WITH
GUSTS UP TO 20 TO 25 MPH FRIDAY AFTER SUNRISE. THIS FRONT WILL
PRODUCE LIGHT TO MODERATE SHOWERS ACROSS THE CWA BEGINNING BY 00Z
FRIDAY AND INCREASING THROUGH THE NIGHT WITH ISOLATED TSTMS
POSSIBLE. FOG WILL BE AN ISSUE TONIGHT FOR A FEW HOURS BEFORE
MIDNIGHT THEN THE FRONT MOVES THROUGH THE AREA HELPING LIFT THE
CLOUD DECK TO 1000 FEET. RAINFALL ACCUMULATIONS WILL REMAIN
BETWEEN LESS THAN A QUARTER OF AN INCH ACROSS THE CWA THROUGH
FRIDAY EVENING. THE MAIN CONCERN WITH THIS COLD FRONT WILL BE THE
LOWER TEMPS LOWERING TO THE LOW TO MID 40S TONIGHT AND REMAIN IN
THE MID 40S INTO FRIDAY. THE OVERCAST SKIES WILL KEEP TEMPERATURES
COOL THROUGH THE DAY FRIDAY WITH BREEZY NORTHERLY WINDS ALLOWING
FOR TEMPERATURES TO FEEL IN THE MID 30S FRIDAY.

FRIDAY NIGHT TEMPERATURES WILL REMAIN IN THE MID TO LOW 30S ACROSS
THE CWA WITH WINDS BETWEEN 15 TO 20 MPH WHICH WILL HELP WIND CHILLS
DROP INTO THE LOW 30S ALONG THE INTERNATIONAL BORDER AND IN THE MID
20S IN THE RANCH LAND. POSSIBLE WIND CHILL ADVISORY CONDITIONS CAN
BE EXPECTED FRIDAY NIGHT INTO EARLY SATURDAY MORNING. AN ADVISORY
MAY BE ISSUED LATER TONIGHT.

LONG TERM /SATURDAY THROUGH WEDNESDAY NIGHT/...STRONG HIGH PRESSURE
WILL STILL BE MOVING SOUTH FROM THE CENTRAL PLAINS INTO SOUTH TEXAS
AND THE NORTHWEST GULF SATURDAY...WITH SOLID OVERRUNNING IN PLACE
OVER SOUTH TEXAS DUE TO SOUTHWEST FLOW ALOFT. THE OMEGA BLOCK AXIS
WILL EXTEND NORTH FROM THE EASTERN PACIFIC TO THE GULF OF ALASKA
WITH A TROUGH OVER THE PACIFIC NORTHWEST. THE IMMEDIATE IMPACT WILL
BE WIND CHILL CONDITIONS FRIDAY NIGHT...HANDLED BY THE SHORT TERM...
BUT ALSO WORTH A MENTION WILL BE THE FORECAST SOUNDING FOR THE
NORTHERN TIER COUNTIES...WHICH HAS A 1000 FOOT WEDGE OF SATURATED
AIR FROM 950 TO 925 MB EXTENDING INTO SUBZERO TEMPERATURES.  THUS...
THOUGH ANY PRECIP WILL BE LIGHT...THERE IS A POSSIBILITY OF WINTRY
PRECIP...PERHAPS LIGHT SLEET...FROM THE OVERNIGHT PERIOD INTO
SATURDAY MORNING ITSELF. HIGH TEMPERATURES SATURDAY WILL ALSO BE
ROUGHLY 25 DEGREES BELOW NORMAL...FROM THE MID TO UPPER 30S ACROSS
THE RANCH LANDS...TO THE MID 40S AT THE COAST. RECORD LOW MAXIMUM
TEMPERATURES ON SATURDAY ARE 48 IN BROWNSVILLE AND HARLINGEN...AND
50 IN MCALLEN. THESE RECORDS WILL BE IN JEOPARDY. FEELS LIKE TEMPS
WILL BE 5 TO 10 DEGREES LOWER BASED ON 10 TO 15 MPH NORTH WINDS.
GUIDANCE IS IN FAIR AGREEMENT...AND FORECAST CHANGES OVERALL ARE
SLIGHT. THE NAM SEEMS TO BE CATCHING UP...RUNNING A BIT HIGHER THAN
MOS GUIDANCE WITH A ROUGH AVERAGE BEING USED. OTHERWISE...LIGHT
NORTH WINDS WILL BE ASSOCIATED WITH LOW OVERCAST SKIES AND A CHANCE
OF LIGHT RAIN AND/OR DRIZZLE ON SATURDAY. SATURDAY NIGHT LOOKS TO BE
JUST A BIT WARMER THAN FRIDAY NIGHT AT THIS POINT...WITH LIGHT NORTH
WINDS...SO WIND CHILL WOULD APPEAR TO BE LESS OF AN ISSUE. THE
REMAINDER OF THE WEEKEND WILL HERALD LITTLE ADDITIONAL CHANGE...WITH
A WEAK WARMING TREND THROUGH MONDAY AS THE AIR MASS SPREADS OUT AND
MODIFIES. HIGH TEMPS ON MONDAY SHOULD BE AT LEAST IN THE 50S WITH A
FEW 60S ACROSS THE LOWER VALLEY.

A SECONDARY FRONT/AIR MASS IS EXPECTED ON MONDAY. THIS AIR WILL HAVE
THE SAME COLD SOURCE REGION AS THE AIR NOW APPROACHING...BUT AS THE
OMEGA BLOCK BREAKS DOWN A BIT OF MARITIME POLAR AIR COULD MIX IN
OVER THE PACIFIC NORTHWEST. NONETHELESS...THE AIR WILL BE COLD. THE
FRONT WILL PUSH THROUGH MONDAY AFTERNOON...AND COASTAL TROUGHING OR
CONVERGENCE COULD PROVIDE ENOUGH MOISTURE CONCENTRATION TO GET SOME
HEAVIER RAIN OVER THE NEAR SHORE GULF...BUT LESS LIKELY OVER THE CWA
ITSELF. COOL TEMPERATURES WILL SINK AGAIN MONDAY NIGHT INTO THE 30S
AND 40S...WITH BORDERLINE WIND CHILL CONDITIONS...AND HIGH TEMPS
TUESDAY ONLY IN THE 40S. A REMNANT TROUGH WILL REMAIN OVER THE
SOUTHWEST AND BACK OVER THE SEA OF CORTEZ/GULF OF CALIFORNIA/NORTH
WEST MEXICO...UNTIL THE UPSTREAM OMEGA LOW RIDES OVER THE TOP OF THE
RIDGE AND FLATTENS EVERYTHING OUT LATER IN THE WEEK. OTHERWISE...THE
LATTER PART OF NEXT WEEK WILL BE A SLOW RECOVERY PERIOD WITH OVC
SKIES AND A SLIGHT CHANCE TO CHANCE OF RAIN...THOUGH WITH DECREASING
CHANCES THROUGH THE WEEK.

MARINE...
NOW THROUGH FRIDAY NIGHT...STRONG NORTHERLY WINDS ARE EXPECTED
BEHIND A STRONG COLD FRONT AROUND MIDNIGHT INTO EARLY FRIDAY
MORNING WITH GUSTY WINDS TO GALE FORCE. THERE IS A GALE WATCH IN
EFFECT FOR EARLY FRIDAY THROUGH EARLY SATURDAY. THE SEAS WILL
INCREASE BETWEEN 10 TO 12 FEET OVER THE GULF WATERS. CHANCE OF
RAINFALL INCREASES THROUGH THE SHORT TERM WITH THE PASSAGE OF THE
FRONT.

SATURDAY THROUGH MONDAY NIGHT...STRONG HIGH PRESSURE WILL BUILD
SOUTH FROM THE CENTRAL PLAINS INTO EAST TEXAS AND THE NORTHWEST GULF
ON SATURDAY...WITH A WEAK COASTAL TROUGH STRETCHING NORTH ALONG THE
NORTHEAST MEXICAN COAST AND THE LOWER TEXAS COASTAL WATERS. SMALL
CRAFT ADVISORY CONDITIONS WILL BE ONGOING ON THE GULF WITH HIGH END
EXERCISE CAUTION WINDS ON THE LAGUNA. WINDS AND SEAS WILL IMPROVE
SATURDAY NIGHT THROUGH SUNDAY AS UPSTREAM HIGH PRESSURE SLIDES EAST
AND THE GRADIENT WEAKENS. RECOVERY TIME WILL BE LIMITED...HOWEVER...
BECAUSE THE NEXT SURGE OF HIGH PRESSURE WILL ARRIVE MONDAY...WITH
STRONG NORTH WINDS AND SMALL CRAFT ADVISORY CONDITIONS...THROUGH
TUESDAY NIGHT IN THE CASE OF GULF WAVE HEIGHTS. A BRIEF PERIOD OF
GALE FORCE GUSTS WILL BE POSSIBLE LATE MONDAY AS SEAS BUILD UP TO 10
FEET OFFSHORE.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  51  51  37  47 /  20  50  40  50
BROWNSVILLE          51  51  37  44 /  20  50  40  50
HARLINGEN            44  44  35  42 /  20  50  40  50
MCALLEN              45  45  37  40 /  10  50  40  40
RIO GRANDE CITY      49  49  37  42 /  20  50  30  40
SOUTH PADRE ISLAND   59  59  42  51 /  20  50  40  50

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...GALE WATCH FROM FRIDAY MORNING THROUGH LATE FRIDAY NIGHT FOR
     GMZ130-132-135-150-155-170-175.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 AM CST FRIDAY FOR GMZ130-
     132-135.

     SMALL CRAFT ADVISORY UNTIL 6 AM CST FRIDAY FOR GMZ150-155-170-
     175.

&&

$$

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

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