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000
FXUS64 KBRO 071727 AAD
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1127 AM CST SAT DEC 7 2013

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

&&

.AVIATION...LOWER LAYER OVERCAST WILL STICK WITH US MOST OF THE
REST OF THE DAY. TRENDS HAVE BEEN IMPROVING A LITTLE AS OF LATE
AND WITH THE EXCEPTION OF RIGHT ALONG THE COAST PROBABLY REMAIN
HIGH MVFR FOR THE NEXT FEW HOURS OR IMPROVING TO JUST ABOVE 3000
FT. WINDS WILL CONTINUE STEADY OUT OF THE NORTH TO NORTHWEST WITH
GUSTS IN THE COASTAL COUNTIES TO NEAR 20 KNOTS. EXPECTING MVFR
CIGS THROUGH THE OVERNIGHT HOURS WITH IFR POSSIBLE NEAR THE COAST
BUT KEPT THE TAFS MORE OPTIMISTIC. /68-JGG/

&&

.PREV DISCUSSION... /ISSUED 1058 AM CST SAT DEC 7 2013/

DISCUSSION...THICK AND PERSISTENT LOW CLOUDINESS HAS LED TO
TEMPERATURES UNDERACHIEVING ABOUT 2 OR 3 DEGREES IN THE COASTAL
COUNTIES AND THAT COUPLED WITH PERSISTENT NORTHWEST WINDS IS
KEEPING WIND CHILLS BETWEEN ABOUT 28 TO 31 DEGREES. WITH FAIRLY
MINIMAL HEATING EXPECTED THROUGH THE NEXT FEW HOURS WIND CHILL
VARIABILITY WILL BE MORE CLOSELY RELATED TO WIND SPEEDS AND THOSE
WILL STAY UP ANOTHER 4 TO 5 HOURS. WITH THAT HAVE EXTENDED THE
WIND CHILL ADVISORY UNTIL 4 PM FOR THE COASTAL COUNTIES AND ALSO
EXTENDED THE SMALL CRAFT ADVISORY FOR THE LAGUNA UNTIL 4PM AS
WELL. GRIDS ADJUSTED AND PRODUCTS SENT ACCORDINGLY. /68-JGG/

MARINE...THE SMALL CRAFT ADVISORY FOR THE LAGUNA MADRE HAS BEEN
EXTENDED UNTIL 4 PM TODAY. /68-JGG/

PREV DISCUSSION... /ISSUED 536 AM CST SAT DEC 7 2013/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...VFR TO MVFR CIGS TO PREVAIL WITH THE LOWER CEILINGS
NEAR THE COAST AND OVER THE THREE REGIONAL AIRPORTS. A SHALLOW
COLD AIRMASS TO REMAIN IN PLACE WITH A STRENGTHENING SOUTH TO
SOUTHWEST FLOW AOB 4K FEET WILL MAINTAIN THICK OVERCAST
CONDITIONS. PATCHY LIGHT RAIN AND DRIZZLE COULD LOWER CEILINGS NEAR
IFR LEVELS BUT THIS SHOULD BE A SHORT DURATION CONDITION WITH LOW
CONFIDENCE IF IT DEVELOPS AND IS NOT MENTIONED IN THE 12Z TAF
PACKAGE. NORTHWEST TO NORTH WINDS AT THE SURFACE GUSTING TO
AROUND 20 KNOTS THIS MORNING DIMINISHING THIS AFTERNOON BECOMING
MOSTLY NORTH AT LIGHT LEVELS TONIGHT.

PREV DISCUSSION... /ISSUED 401 AM CST SAT DEC 7 2013/

SHORT TERM /NOW THROUGH SUNDAY/...THICK CLOUD COVER AND A
STRONG SOUTHWEST FLOW ALOFT KEEPING TEMPERATURES FROM FALLING MORE
THEN THE MODELS AND FORECAST INDICATED. EVEN WITH DECENT CAA
ADVECTION ALL NIGHT TEMPERATURES HAVE NOT APPROACHED FREEZING
ACROSS THE NORTHERN ZONES. TEMPERATURES HAVE LOWERED IN THE LOWER
VALLEY AND ALONG THE COAST WHERE LIGHT RAIN/DRIZZLE HAS DEVELOPED
CREATING WEAK EVAPORATE COOLING. CANCELLED THE FREEZE WARNING BUT
MAINTAINED THE WIND CHILL ADVISORIES WITH VALUES OF 25 TO 30
DEGREES STILL POSSIBLE WITH A FEW MORE HOURS OF COOLING TO TAKE
PLACE AND A MODERATE NORTH WIND PERSISTING.

THE THICK CLOUD COVER TO PERSIST TODAY WITH INCREASING SOUTHERLY
FLOW MAINTAINING DECENT ISENTROPIC UPGLIDE. RAIN CHANCES HOWEVER
REMAIN A CHALLENGE WITH BEST CHANCES OVER THE COASTAL REACHES WHERE
A WEAK COASTAL TROUGH/LOW DEVELOPS LATER TODAY AND TONIGHT. THE
RAIN/DRIZZLE TO INCREASE IN AREAL COVERAGE SPREADING FARTHER WEST
TONIGHT AS THE ISENTROPIC LIFT STRENGTHENS WITH THE SOUTHERLY WAA
INCREASINGS IN ADVANCE OF AN UPPER LEVEL DISTURBANCE AND STRONG JET
MAX MOVING INTO CALIFORNIA. AS THIS JET MAX MOVES FARTHER EAST
CROSSING THE SOUTHERN PLAINS SUNDAY MORNING IT EVENTUALLY KICKS THE
COASTAL TROUGH/LOW NORTHEAST WITH RAIN CHANCES DIMINISHING WEST TO
EAST SUNDAY AFTERNOON.

TEMPERATURES LOOK TO HAVE A NARROW DIURNAL RANGE TODAY AND TONIGHT.
CHALLENGE LIES IN HOW FAST AND HOW MUCH A MODEST WARM UP DEVELOPS
SUNDAY. CLOUD COVER AND CONTINUED CAA TO KEEP TEMPERATURES WELL
BELOW NORMAL TODAY BUT WITH MORNING LOWS EXPECTED A FEW DEGREE
WARMER DAYTIME HIGHS IN TURN HAVE BEEN RAISED A FEW DEGREES. MODELS
ALSO INDICATING SLIGHTLY HIGHER NUMBERS. TRANSITION TOWARDS SLIGHTLY
WARM TEMPS BEGINS TONIGHT. TEMPERATURES FALL A FEW DEGREES BEFORE
MIDNIGHT THE TO REMAIN STEADY OR RISE TOWARDS SUNDAY MORNING AS
WINDS TURN NORTHEAST AND WEAKEN. THICKNESS VALUES RISE AND SURFACE
HIGH PRESSURE SHIFTS TO THE EAST SUNDAY WITH THE SLIGHTLY WARMER
GULF WATERS WARMING TEMPERATURES UP A AROUND 5 TO 10 DEGREES OVER
TODAY.

LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...COASTAL TROUGHING
ALONG WITH THE BOUNDARY THAT IS THE CULPRIT FOR THE COLD AIR
ACROSS THE AREA WILL SLOWLY LIFT NORTHWARD AS ANOTHER SHORTWAVE
TROUGH EJECTS FROM THE SOUTHWEST BRINGING A REINFORCEMENT OF COLDER
AIR FROM THE NORTHWEST. WITH THE PREVIOUS FRONT IN THE
AREA...CHANCES /ALBEIT LOW/ FOR LIGHT RAIN AND DRIZZLE WILL
CONTINUE SUNDAY NIGHT AND MONDAY. CLOUDS WILL CONTINUE TO HANG
TOUGH WHICH WILL KEEP LOWS FROM BOTTOMING OUT AND HIGHS FROM
REACHING THEIR FULL POTENTIAL. THUS...LOWS IN THE 40S AND HIGHS IN
THE 50S WILL BE COMMON. REINFORCEMENT COMES THROUGH MONDAY AND
MONDAY NIGHT WITH FRESH HIGH PRESSURE WORKING INTO THE REGION.
THIS WILL KNOCK TEMPERATURES BACK DOWN AROUND 10 DEGREES TUESDAY
AND WEDNESDAY WITH LOWS REMAINING ABOVE FREEZING UNDER THICKER
CLOUD COVER AND INCREASING ISENTROPIC LIFT ONCE AGAIN.
THEREFORE...LIGHT RAIN AND DRIZZLE WILL REMAIN IN THE FORECAST
WEDNESDAY THROUGH FRIDAY. BETTER CHANCES THE EAST ONE GOES BUT
AMOUNTS WILL REMAIN ON THE LIGHT SIDE. HAVE UNDERCUT TEMPERATURE
GUIDANCE SLIGHTLY THURSDAY AND FRIDAY AS THICKER CLOUD COVER AND
LIGHT RAIN WILL KEEP HIGHS A LITTLE LOWER.

MARINE...NOW THROUGH SUNDAY...SMALL CRAFT ADVISORIES CONDITIONS
HAVE BE EXTENDED AS NORTH WINDS CONTINUE AT STRONG LEVELS. WINDS
TO LOWER OVER THE LAGUNA THIS AFTERNOON ALLOWING FOR THE SCA TO
END BUT EXERCISE CAUTION WORDING WILL BE LIKELY. PRESSURE GRADIENT
WEAKENS FURTHER LATER TONIGHT WITH IMPROVING CONDITIONS THROUGH
SUNDAY. PATCHY DRIZZLE AND COLD TEMPERATURES CONTINUE TODAY WITH
NOT AS COLD CONDITIONS ON SUNDAY.

SUNDAY NIGHT THROUGH WEDNESDAY...MONDAY LOOKS TO BE THE LULL BEFORE
THE NEXT FRONT WITH SEAS AROUND 5 FEET AND WINDS FROM THE NORTH AT
10-15 KNOTS. HAZARDOUS CONDITIONS RETURN ON NORTHERLY WINDS UP TO 30
KNOTS MONDAY NIGHT THROUGH WEDNESDAY AND SEAS BACK UP TO 10 FEET.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...WIND CHILL ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR TXZ251-
     254>257.

GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM CST THIS AFTERNOON FOR
     GMZ130-132-135.

     SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR GMZ150-155-
     170-175.

&&

$$

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