000
FXUS64 KBRO 161725 AAB
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1225 PM CDT THU MAY 16 2013

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

.AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE
MOSTLY CLEAR SKIES ACROSS THE CWA EARLY THIS AFTERNOON. CEILINGS
WERE NEAR 2400FT AT KPIL TO NEAR 2600FT AT KBRO. EXPECT VFR
CONDITIONS TO PREVAIL ACROSS THE RIO GRANDE VALLEY THE REST OF THE
AFTERNOON INTO THE EVENING AS WEST TO NORTHWEST FLOW ALOFT
CONTINUES TO PROVIDE SUBSIDENCE ACROSS THE AREA. MVFR CEILINGS WILL
DEVELOP TONIGHT AS LOW TO MID LEVEL MOISTURE ALLOWS LOW CLOUDS TO
DEVELOP AS MIXING DECREASES WITH THE LOSS OF DIURNAL HEATING.
&&

.PREV DISCUSSION... /ISSUED 658 AM CDT THU MAY 16 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...IR SATL IMAGERY SHOWS PATCHY AREAS OF LOW LEVEL SC
FORMING UP MAINLY EAST OF HIGHWAY 281 AS THE MOIST NOCTURNAL LOW
LEVEL INVERSION PERSIST. THESE LOW LEVEL DECKS WILL PERSIST THROUGH
THE MID MORNING HOURS. AS THE DAYTIME HEATING AND LOW LEVEL
MIXING INCREASES THE LOW LEVEL INVERSION WILL ERODE ALLOWING THE
CEILINGS TO INCREASE OR DISSIPATE. EXPECT SOME MVFR/IFR CEILINGS TO
PREVAIL THROUGHOUT THE EARLY MORNING HOURS WITH MVFR TO VFR
CONDITIONS EXPECTED AFTER SUNRISE AND CONTINUING THROUGH SUNSET
TONIGHT. ANOTHER ROUND OF LOW CEILINGS WILL BE POSSIBLE AGAIN LATER
TONIGHT AS THE NIGHTTIME MOIST INVERSION REFORMS.

PREV DISCUSSION... /ISSUED 349 AM CDT THU MAY 16 2013/
SHORT TERM.../TODAY THROUGH FRIDAY/...A LARGE 500 MB CLOSED LOW
OVER SOUTH CENTRAL OK WILL CONTINUE TO SHIFT EAST TODAY AND
TOMORROW ALLOWING MID LEVEL RIDGING AND DRIER AIR TO FILTER INTO
THE REGION THROUGHOUT THE SHORT TERM. A LARGE CONV COMPLEX IS
MOVING SE ACROSS EAST TX AHEAD OF THIS CLOSED LOW. THIS COMPLEX
WILL NOT MAKE ANY PROGRESS TOWARDS DEEP SOUTH TX TODAY AS THE
MOISTURE AND INSTABILITY OVER DEEP SOUTH TX IS DIMINISHING
STEADILY. ON FRIDAY ANOTHER DEEP 500 MB TROUGH AXIS WILL DIG
TOWARDS THE SOUTHWESTERN STATES WHICH WILL RESULT IN ANOTHER
FAIRLY STRONG SURFACE LOW OVER THE SOUTH CENTRAL PLAINS STATES. SO
THE PGF WILL REMAIN PRETTY STRONG THROUGHOUT THE SHORT RANGE
MAINTAINING THE BREEZY TO WINDY CONDITIONS. THE KBRO VWP SUPPORTS
THIS BY SHOWING A PRETTY STRONG LLJ OF AROUND 50 KTS AT 2KFT. AT
THIS TIME THE LOW LEVEL INVERSION OVER SOUTH TX ALSO INDICATED BY
THE 00Z BRO SOUNDING WILL WEAKEN BUT WILL REMAIN ENTRENCHED
THROUGHOUT THE AFTERNOON. THIS MAY LIMIT HOW THE LLJ WILL MIX DOWN
TO THE SURFACE. SO WILL NOT POST ANY WIND ADVISORIES AT THIS TIME.

THE MORNING IR SATL DATA SHOWS SOME AREAS OF LOW LEVEL SC DECKS OVER
THOSE AREAS MAINLY EAST OF HIGHWAY 281. THESE DECKS WILL LIKELY MIX
OUT LATER THIS AFTERNOON ALLOWING FOR MORE SUNSHINE. THIS IN
COMBINATION WITH THE INCREASING MID LEVEL AND SURFACE RIDGING WILL
ALLOW THE AFTERNOON HIGHS TO WARM UP QUICKLY. WILL GO CLOSE TO A MAV
AND MET TEMP BLEND THROUGH FRI. THE ECMWF HIGH TEMPS LOOK A LITTLE
TOO COOL ESPECIALLY IN THE FIRST PERIOD.

LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
LITTLE CHANGE IN THE LONG TERM REASONING. FAIRLY STRONG UPPER
CONVERGENCE WITH RIDGING IN PLACE AHEAD AND TO THE NORTHWEST. WEST
SOUTHWESTERLY SUBTROPICAL JET WILL INDUCE SOME LEE TROUGHING WHICH
WILL KEEP AT LEAST BREEZY CONDITIONS IN PLACE THROUGH THE WEEK. A
CENTRAL PLAINS TROUGH AND ASSOCIATED SURFACE LOW WILL GET GOING
FRIDAY NIGHT THROUGH MONDAY AND THAT PERIOD CONTINUES TO LOOK TO
FEATURE THE STRONGEST WINDS FOR THIS AREA. BORDERLINE WIND ADVISORY
CONDITIONS WILL BE POSSIBLE MAINLY NEAR THE COAST AT PEAK
TIMES...WITH THE CURRENT FORECAST KEEPING WINDS BELOW THAT LEVEL BY
A FEW MPH. KEPT WINDS DOWN AND BACKED THEM ALONG THE COAST WITH THE
NEAR SFC INVERSION/MARINE LAYER IN PLACE SO THE TYPICAL STRONG WINDS
ALONG THE WESTERN LAGUNA MADRE AND LIGHTER WINDS ON SOUTH PADRE
ISLAND PATTERN IN SOUTHEASTERLIES LOOKS TO BE THE RULE.

TEMPERATURES REMAIN LITTLE CHANGED WITH OPERATIONAL AND ENSEMBLE
GUIDANCE CLUSTERED CLOSELY TOGETHER. SUNDAY THE ONLY OUTLIER AS SFC
TROUGHING GETS A LITTLE CLOSER TO THE REGION AND OUR LOW LEVEL WINDS
ARE SLIGHTLY MORE SOUTHERLY WHICH COULD SEE HIGHER MAX TEMPS BUILD
IN NEAR THE COAST. EXPECTING LOW TO MID 80S ON THE ISLAND UPPER 80S
TO LOW 90S COASTAL...BUILDING TO UPPER 80S AND LOW 100S IN THE WEST
THROUGH THE WEEK.  DRY SUBSIDING AIR AT 850 TO 700MB SHOULD MIX DOWN
IN THE AFTERNOON LOWERING THE DEWPOINT ENOUGH TO KEEP HEAT INDICES
FROM REALLY TAKING OFF BUT 100 TO 105 WILL PROBABLY BE FAIRLY
COMMONPLACE IN THE LATE MORNING TO AFTERNOON HOURS THROUGH THE WEEK.
A LACK OF DEPTH OF LOW MOISTURE AND STRONG SUBSIDENCE INVERSION
INDUCED CAPPING SHOULD KEEP ANY NOTABLE RAIN CHANCES AT BAY FOR THE
WEEK AS WELL.

MARINE...TODAY THROUGH FRIDAY...THE STRONG PGF THAT WILL PREVAIL
OVER THE LOWER TX BAY AND GULF WATERS TODAY AND FRI WILL KEEP THE
SOUTHERLY WINDS IN THE SCEC/SCA RANGE THROUGHOUT THE SHORT TERM.
BUOY020 CURRENTLY CHECKS IN WITH A SOUTH WIND AROUND 20 KNOTS WITH
SWELLS AROUND 6.0 FEET. WILL MAINTAIN THE SCA FOR THE GULF WATERS
THROUGH THE LATE MORNING HOURS. EXPECT THE PGF TO MIX DOWN ENOUGH
ACROSS THE BAY WATERS LATER THIS AFTERNOON TO REACH SCA LEVELS. SO
WILL POST UP AND SCA FOR THE LAGUNA MADRE STARTING LATER THIS
MORNING AND CONTINUING INTO THE EARLY EVENING.

FRIDAY NIGHT THROUGH TUESDAY...
SMALL CRAFT ADVISORIES MAY BE NEEDED FRIDAY NIGHT THROUGH SATURDAY
NIGHT DUE TO STRONG SOUTH TO SOUTHEAST WINDS. THE ADVISORIES ARE
MOST LIKELY DURING THE NORMAL FAVORED TIMES FOR STRONGER WINDS...IN
THE AFTERNOON ON THE LAGUNA...AND THE EVENING AND OVERNIGHT ON THE
OPEN GULF WATERS. WINDS ARE EXPECTED TO SUBSIDE MORE INTO THE
EXERCISE CAUTION RANGE ON SUNDAY AFTERNOON THROUGH TUESDAY WITH SEAS
GENERALLY REMAINING MODERATE TO BRIEFLY ROUGH IN THE STRONGEST
WINDS.
&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM CDT THIS EVENING FOR
     GMZ130-132-135.
&&

$$

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