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000
FXUS64 KBRO 181826 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
126 PM CDT TUE JUN 18 2013

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

&&

.AVIATION...THE 12Z BRO SOUNDING INDICATED A PRETTY PARCHED
AIRMASS IN PLACE OVER THE REGION WITH ONLY SOME VERY SHALLOW
MOISTURE EVIDENT FROM 950 TO 1000 MB. ACCORDINGLY THE AFTERNOON
HEATING HAS PRODUCED ONLY SOME PATCHY SC AROUND THE LOWER RGV
WHICH SHOULD PERSIST ON INTO THE EARLY EVENING. THE GFS FORECAST
SOUNDINGS SHOWS A SMALL WINDOW OF OPPOROTUNITY FOR SOME LATE
NIGHT/EARLY MORNING CLD COVER AS SHALLOW SATURATED LAYER FORMS FOR
A FEW HOURS AROUND 12Z NEAR 975 MB. THE NAM FORECAST SOUNDINGS DO
NOT SHOW THIS SATURATED LAYER WITH THE TEMP AND DEWPOINT GAP
WIDENING THROUGHOUT THE NEXT 24 HOURS. WILL GO CLOSER TO THE NAM
GUIDANCE MAINTAINING VFR CONDITIONS THROUGH 18Z TOMORROW FOR ALL
OF THE LOWER RGV AIRPORTS.

&&

.PREV DISCUSSION... /ISSUED 627 AM CDT TUE JUN 18 2013/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...VFR CONDITION WILL PREVAIL TODAY WITH A FEW CIRRUS
CLOUDS STREAMING ACROSS THE AREA FROM CONVECTION ACTIVITY OVER
NORTHERN TEXAS. SOUTHEAST WINDS WILL GRADUALLY INCREASE BY MID
DAY WITH GUSTS UP TO 25 KNOTS AND REMAIN BREEZE THROUGH THE
EARLY EVENING HOURS. EXPECT LIGHTER WINDS AFTER MIDNIGHT WITH
MVFR CONDITIONS RETURNING BEFORE SUNRISE.

PREV DISCUSSION... /ISSUED 410 AM CDT TUE JUN 18 2013/

SHORT TERM /NOW THROUGH WEDNESDAY/...STRONG UPPER LEVEL RIDGE OVER
THE PACIFIC AND NORTHERN MEXICO WILL CONTINUE TO BUILD AND EXTEND
INTO SOUTHERN TEXAS TODAY. THIS WILL KEEP THE LOWER TEXAS REGION
UNDER A NORTHWEST FLOW ALOFT. THE 1500 FT CLOUD DECK WILL BEGIN TO
BREAK A FEW HOURS AFTER SUNRISE AS DAYTIME HEATING BEGINS ANS SE
WINDS BEGIN TO INCREASE. SURFACE HIGH ACROSS THE GULF OF MEXICO
WILL MIGRATE EAST WEAKENING THE SFC GRADIENT ALONG SOUTH TEXAS
COAST TODAY. THE SOUTHEAST WINDS WILL SLOWLY BEGIN INCREASE
THROUGH THE DAY WITH GUSTS AROUND 20 MPH ESPECIALLY DURING PEAK
HEATING THIS AFTERNOON...BUT IT WILL NOT BE AS BREEZE COMPARED TO
MONDAY. HIGH TEMPERATURES WILL REACH THE TRIPLE DIGITS ONCE AGAIN
ACROSS THE CENTRAL AND WESTERN PORTION OF THE CWA AND NEAR THE
100S EAST OF HWY 281. HUMIDITY WILL RANGED BETWEEN 30 TO 40
PERCENT ACROSS THE CWA AND IN THE LOW 30S FROM RIO GRANDE CITY
NORTH TO ZAPATA. HIGH TEMPERATURES WILL FEEL HOTTER RANGING FROM
105 TO 108 DEGREES THIS AFTERNOON. AS THIS RIDGE BUILDS...THE CAP
WILL STRENGTHEN ACROSS THE AREA LIMITING ANY CHANCE OF CONVECTION
THROUGH THE SHORT TERM FORECAST.

IN THE EVENING...THE SE WINDS WILL REMAIN BREEZE IN THE EVENING AS
THE GRADIENT STRENGTHENS LIMITING THE LOW CLOUDS TO DEVELOP AS
QUICKLY. EXPECT THE SE WINDS TO DECOUPLE CLOSE TO MIDNIGHT AND THE
LOW LEVEL CLOUD TO DEVELOP. LOW TEMPERATURES WILL REMAIN IN THE
UPPER 70S ACROSS THE CWA AND IN THE 80S ALONG THE COAST. HUMIDITY
RECOVERIES WILL EXCELLENT WITH VALUES NEAR 90 PERCENT ACROSS THE
CWA. RIDGE WILL MIGRATE EAST BY WEDNESDAY WITH ITS AXIS ENTERING THE
TEXAS REGION. AT THE SURFACE...THE GRADIENT WILL STRENGTHEN KEEPING
THE RGV UNDER BREEZE CONDITIONS THROUGH THE DAY. EXPECT HIGH TEMPS
TREND ONE TO TWO DEGREES HIGHER INTO WEDNESDAY.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...BECOMING INCREASINGLY
MORE DIFFICULT EVERY DAY TO TALK ABOUT NOTHING. THE STRONG UPPER
LEVEL RIDGE MENTIONED ABOVE IN THE SHORT TERM FORECAST DISCUSSION
WILL GRADUALLY BECOME AND REMAIN CENTERED OVER THE LONE STAR STATE
DURING THE PERIOD...AND EXTENDED OVER THE RIO GRANDE VALLEY AND
DEEP SOUTH TEXAS. DRY WEATHER WITH VERY HOT TEMPERATURES CONTINUES
TO BE EXPECTED THROUGHOUT THE LONG TERM FORECAST PERIOD. HOWEVER...
ALL MAY NOT BE LOST...AS AT LEAST THE GFS MODEL DEVELOPS A 500 MB
CLOSED LOW PRESSURE SYSTEM OVER THE SOUTHEAST UNITED STATES...AND
RETROGRADES THAT FEATURE TOWARDS THE BRO CWFA DURING THE LATTER
HALF OF THE PERIOD. QUITE POSSIBLY COULD HAVE INDICATED A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR PORTIONS OF DEEP SOUTH
TEXAS AND THE RIO GRANDE VALLEY DURING THE DAYLIGHT HOURS OF
SATURDAY THROUGH MONDAY IN ASSOCIATION WITH THE 500 MB LOW AND
DEEPER TROPICAL MOISTURE...WITH PRECIPITABLE WATER VALUES BETWEEN
1.50 AND 2.00 INCHES...BUT SINCE INHERITED A DRY FORECAST...WILL
MAINTAIN IT FOR NOW...AND REVISIT THE ISSUE IN 24 HOURS.

MARINE...NOW THROUGH WEDNESDAY...AT THIS TIME SEAS ARE NEAR 5 FEET
OFFSHORE WITH SOUTHEAST WINDS BETWEEN 15 TO 20 KNOTS PROVIDING ROUGH
CONDITIONS OVER THE GULF WATERS THROUGH SUNRISE. CONDITIONS WILL
BEGIN TO IMPROVE DURING THE DAY AS THE GRADIENT WEAKENS AND THE
UPPER LEVEL RIDGE CONTINUES TO BUILD FROM THE WEST. EXPECT SCEC
CONDITIONS OVER THE BAY TODAY WITH LIGHTER WINDS OVER THE GULF. THE
WINDS WILL STRENGTHEN BY LATE AFTERNOON AND REMAIN BREEZE A LITTLE
LONGER THROUGH THE NIGHT PROVIDING SCEC CONDITIONS TO RETURN FOR A
FEW HOURS. EXPECT THE SE WINDS TO DECOUPLE BY MIDNIGHT WITH SEAS 2
TO 4 FEET. THE SURFACE GRADIENT WILL BE MORE ORGANIZED INTO
WEDNESDAY ALONG THE COAST WITH SE WINDS BETWEEN 15 TO 20 KNOTS AND
SEAS GRADUALLY BUILDING 3 TO 5 FEET BY LATE WEDNESDAY.

WEDNESDAY NIGHT THROUGH MONDAY...ALTHOUGH MODERATE WINDS ARE LIKELY
ALONG THE LOWER TEXAS COAST THROUGH THE PERIOD...AN INCREASE IN SEAS
WILL OCCUR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...AS THE BROAD WIND
FIELD ASSOCIATED WITH TROPICAL DEPRESSION 2 IN THE BAY OF CAMPECHE
AT THAT TIME CAUSES SWELL FROM THE SOUTHEAST TO EAST TO AFFECT THE
LOWER TEXAS COAST...WITH SMALL CRAFT EXERCISE CAUTION POSSIBLE FOR A
PORTION OF THE GULF OF MEXICO WATERS EAST OF PADRE ISLAND. SEAS WILL
BECOME MORE FAVORABLE DURING THE WEEKEND AND EARLY NEXT WEEK AS THE
SWELL DISSIPATES.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  80  94  79  92 /   0   0   0   0
BROWNSVILLE          79  95  77  96 /   0   0   0   0
HARLINGEN            77  97  76  97 /   0   0   0   0
MCALLEN              79 100  77 100 /   0   0   0   0
RIO GRANDE CITY      78 102  78 103 /   0   0   0   0
SOUTH PADRE ISLAND   81  92  80  89 /   0   0   0   0

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

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

SHORT TERM...60
LONGER TERM...64
GRAPHICAST/UPPER AIR...MARTINEZ