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000
FXUS64 KBRO 121938
AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
238 PM CDT WED JUN 12 2013

.SHORT TERM /NOW THROUGH THURSDAY NIGHT/...LINGERING UPPER LEVEL LOW
WILL CONTINUE TO SHIFT WEST OVER NORTH CENTRAL MEXICO AND OVER THE
BIG BEND AREA BY THURSDAY NIGHT...WHILE MID-LEVEL RIDGING SHIFTS
EAST AND BECOMES CENTERED OVER THE ARK-LA-TEX REGION. MODEL GUIDANCE
IS IN FAIRLY GOOD AGREEMENT IN THE TIMING AND MOVEMENT OF THIS
FEATURE.

THE CONVECTIVE COMPLEX THAT HAD BEEN OVER NORTHERN MEXICO EARLY
THIS MORNING DID NOT MAKE MUCH HEADWAY INTO THE RGV TODAY AND HAS
FOR THE MOST PART DISSIPATED. THE BIG QUESTION ONCE AGAIN TODAY IS
WHETHER THE SEABREEZE WILL FIRE ANY CONVECTION THIS AFTERNOON ACROSS
THE EASTERN HALF OF THE REGION. HAVE MAINTAINED A SLIGHT CHANCE OF
POPS BUT CONFIDENCE IS LOW IN THAT THIS WILL HAPPEN. A NUMBER OF
FACTORS APPEAR TO BE LIMITING CONVECTION TODAY...STRONGER SURFACE
WINDS AND SOUTHERLY FLOW FROM 925 THROUGH 700 MB. MAINTAINED
SLIGHTLY HIGHER POPS FOR THE WESTERN THREE COUNTIES AND WITHIN THE
LAST HOUR CONVECTION HAS BEGUN TO FIRE OVER JIM HOGG AND STARR
COUNTIES.

AS THE UPPER LEVEL LOW DRIFTS WEST...SOME DIFFLUENCE WILL REMAIN
OVER THE AREA THURSDAY AFTERNOON AND THE COLUMN WILL REMAIN FAIRLY
MOIST...SO HAVE CONTINUED TO MENTION A SLIGHT CHANCE OF PRECIP FOR
THURSDAY. NAM/ECMWF REMAIN WETTER FOR POPS THROUGH THE FORECAST
PERIOD WHILE THE GFS TRENDS DRIER...OPTED TO GO FOR A DRIER SOLUTION
SINCE THE NAM/ECMWF HAVE NOT HANDLED PRECIP WELL THE LAST FEW DAYS.
PRECIP CHANCES START TO DIMINISH THURSDAY NIGHT AS THE UPPER LEVEL LOW
DRIFTS FURTHER WEST AND DRIER AIR BEGINS TO FILTER IN.

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
NOT A GREAT DEAL OF CHANGE IN THE LONG TERM REASONING THIS
AFTERNOON. FRIDAY WE WILL MAINTAIN FAIRLY DEEP COLUMN MOISTURE BUT
LITTLE LOW LEVEL CONVERGENCE TO INITIATE CONVECTION. ON THE COAST
SFC HEATING SHOULD MIX DRY AIR DOWN SUFFICIENTLY TO PREVENT THE
SEABREEZE FROM HAVING THE DEPTH OF CONVERGENCE NEEDED TO START UP
THUNDER. FURTHER WEST THOUGH A MODERATELY DIFFLUENT REGION OF THE
SUBTROPICAL JET...AS IT TURNS AT THE BASE OF STRONG UPPER
RIDGING...MAY OPEN A CONVECTIVE WINDOW AND HAVE KEPT THE INHERITED
POPS LARGELY IN PLACE. NAM IS MORE AGGRESSIVE BUT BELIEVE IT IS
BEING TOO GENEROUS WITH LOW LEVEL RH VALUES.

THROUGH THE WEEKEND INTO NEXT WEEK MID AND UPPER LEVEL RIDGING SET
UP FROM SOUTHERN NEW MEXICO INTO THE PANHANDLE REGION OF TEXAS WITH
GOOD AGREEMENT ON THIS FEATURE BETWEEN THE GFS AND ECMWF AS WELL AS
THEIR ENSEMBLE COUNTERPARTS. WITH THAT EXPECT MODERATE SOUTHEAST
WINDS AND WARM TEMPERATURES. AFTERNOON HIGHS NEAR 90 TO 92 COASTAL
98 TO 102 FAR WEST LOOK REASONABLE AND LITTLE TWEAK OR CHANGE IS
NEEDED TO THE INHERITED FORECAST.

BY WEDNESDAY GFS/ECMWF SHOW AN INVERTED TROUGH/TROPICAL WAVE IN THE
SOUTHERN BAY OF CAMPECHE. BLOCKING RIDGING IS FIRMLY PARKED OVER
SOUTH TEXAS BY THIS POINT AND IT APPEARS THAT EVEN IF THIS FEATURE
COMES TO FRUITION...AND AT THAT RANGE AND ESPECIALLY IT SEEMS THAT
AREA OF THE GULF...THE GLOBAL MODELS DO NOT HAVE A GREAT DEAL OF
SKILL AT PROJECTING...THAT IT WOULD BE PREVENTED FROM SENDING MUCH
IN THE WAY OF MOISTURE OUR WAY. GFS AND ECMWF DETERMINISTIC PWAT/RH
FIELDS INDICATE THE SAME...SO LEFT THE FORECAST COMPLETELY DRY WITH
A CLIMATOLOGY/GLOBAL MODEL BLEND OF SOUTHEASTERLY SURFACE WINDS AND
TEMPERATURES.


&&

.MARINE...NOW THROUGH THURSDAY NIGHT...MODERATE SOUTHEAST WINDS AND
MODERATE SEAS WILL PREVAIL THROUGH THURSDAY NIGHT AS SURFACE HIGH
PRESSURE OVER THE GULF INTERACTS WITH LOWER SURFACE PRESSURE OVER
THE CENTRAL US. WINDS MAY BRIEFLY APPROACH SMALL CRAFT EXERCISE
CAUTION CONDITIONS TONIGHT ACROSS THE GULF WATERS. ISOLATED SHOWER
AND THUNDERSTORM ACTIVITY WILL CONTINUE THROUGH THURSDAY.

THURSDAY NIGHT THROUGH SUNDAY...
GENERALLY FAVORABLE MARINE CONDITIONS ARE ANTICIPATED DURING THE
LONG RANGE PERIOD. MODERATE SOUTHEASTERLY WINDS ARE ANTICIPATED WITH
MODERATE SEAS. WINDS MAY APPROACH EXERCISE CAUTION LEVELS SATURDAY
AND SUNDAY NIGHT BUT AT THIS POINT IS APPEARS THEY WILL REMAIN BELOW
THRESHOLDS.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  80  91  78  93 /  10  20  10  10
BROWNSVILLE          78  93  77  93 /  10  20  10  10
HARLINGEN            77  95  77  94 /  10  20  10  10
MCALLEN              78  98  77  97 /  10  20  10  10
RIO GRANDE CITY      78  99  76 100 /  10  20  20  20
SOUTH PADRE ISLAND   81  89  79  92 /  20  20  10  10

&&

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

$$

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

SHORT TERM...58-BILLINGS
LONG TERM...68-GIBBS
UPPER AIR/GRAPHICAST...VEGA