AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
131 PM CDT THU MAY 12 2011

.NEAR TERM...WW288 WILL EXPIRE AT 3 PM. WILL COORD WITH SPC
IN THE EVENT A NEW WW WILL BE NEEDED FURTHER SOUTH LATER THIS
AFTERNOON. SO FAR RECENT TRENDS FROM BOTH CRP AND BRO RADARS
INDICATE THAT THE SOUTH END OF THE CONV LINE MOVING TOWARDS THE
COASTLINE HAS BEEN GRADUALLY WEAKENING AS IS PUSHES ESE. HOWEVER
THE CELLS AT THE SOUTHERNMOST END OF THE LINE OVER SOUTHERN WEBB
COUNTY REMAINS PRETTY POTENT AND MAY REQUIRE AN SVR T-STORM
WARNING FOR EITHER ZAPATA OR JIM HOGG COUNTIES. A QUICK LOOK AT
THE LAPS CAPE VALUES INDICATES THAT THIS WEAKENING MAY BE DUE TO
THE CELLS MOVING INTO A LITTLE MORE STABLE AIR POOLING OVER THE
WESTERN PORTIONS OF THE BRO CWA. HOWEVER VSBL SATL IMAGERY SHOWS
THAT THE CLD COVER SOUTH OF THE CONV HAS MIXED OUT ALLOWING FOR
BETTER DAYTIME HEATING OVER THE REGION WHICH COULD DESTABILIZE THE
ATMS ONCE AGAIN DURING THE AFTERNOON HOURS. IF ENOUGH
DESTABILIZATION OCCURS OVER THE NEXT SEVERAL HOURS AND THE CONV
TO OUR NORTH LAYS OUT SOME STRONG OUTFLOW BOUNDARIES ADDITIONAL
STRONG CONV MAY REFORM OVER THE NEXT SEVERAL HOURS. ACCORDINGLY
WILL MAINTAIN FAIRLY HIGH POPS DURING THE NEXT 2 TO 4 HOURS WITH
POPS THEN DROPPING QUITE A BIT LATER THIS EVENING AS THE CONV
CLEARS THE REGION AND MORE STABLE OUTFLOW DOMINATES.
&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...THERE IS A SLIGHT
CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS MOVING ACROSS
PORTIONS OF DEEP SOUTH TEXAS OVERNIGHT TONIGHT. THE RAIN CHANCES
DIMINISH ON FRIDAY. THE WINDS WILL CONTINUE LIGHT TO MODERATE FROM
THE SOUTHEAST THROUGH FRIDAY MORNING. A WEAK COLD FRONT WILL MOVE
THROUGH DEEP SOUTH TEXAS ON FRIDAY SHIFTING THE WINDS TO THE
NORTH. HOWEVER THE WINDS WILL REMAIN LIGHT TO MODERATE FROM THE
NORTH BEHIND THE FRONT THROUGH SATURDAY MORNING. THE TEMPERATURES
WILL BE A LITTLE COOLER THE NEXT FEW DAYS DUE TO INCREASED
CLOUDINESS AND IN THE WAKE OF THE FRONT. HOWEVER THE TEMPERATURES
WILL REMAIN ABOVE NORMAL.
&&

.LONG TERM...MID LEVEL AND SURFACE RIDGING WILL BECOME MORE
ESTABLISHED OVER THE REGION LATER IN THE FORECAST PERIOD.
FORTUNATELY THE 1000-500 MB THICKNESSES WILL BE SHALLOWER
COMPARITIVELY TO THE LAST COUPLE OF WEEKS WHICH WILL IN TURN ALLOW
OVERALL TEMPS TO REMAIN NEAR TO BELOW CLIMO FOR MID MAY. WILL
MAINTAIN NIL POPS FOR THE MOMENT AS OVERALL MOISTURE VALUES REMAIN
PRETTY LIMITED ACROSS THE REGION.
&&

.MARINE...TONIGHT THROUGH FRIDAY NIGHT...THERE IS A SLIGHT CHANCE
FOR SHOWERS AND ISOLATED THUNDERSTORMS MOVING ACROSS PORTIONS OF THE
MARINE AREAS TONIGHT IN ADVANCE OF A WEAK COLD FRONT WHICH WILL MOVE
THROUGH THE COASTAL WATERS FRIDAY. THE WINDS AND SEAS WILL INCREASE
IN OR NEAR ANY SHOWERS OR THUNDERSTORMS. ONCE THE FRONT PASSES THE
WINDS WILL SHIFT TO THE NORTH. HOWEVER THE WINDS WILL CONTINUE
MODERATE AND MODERATE SEAS WILL PREVAIL ACROSS THE MARINE AREAS FOR
THE NEXT FEW DAYS. IN THE EXTENDED RANGE PERIOD THE PGF WILL
REMAIN FAIRLY WEAK WHICH WILL ALLOW GENERALLY BENIGN WINDS AND
SEAS TO PREVAIL. NO SCA CONDITIONS EXPECTED AT THIS TIME.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  77  89  73  86 /  30  10   0   0
BROWNSVILLE          76  91  72  89 /  30  10   0   0
HARLINGEN            77  94  71  90 /  30  10   0   0
MCALLEN              77  96  72  92 /  30  10   0   0
RIO GRANDE CITY      76  98  71  93 /  30  10   0   0
SOUTH PADRE ISLAND   77  85  75  80 /  30  10   0   0

&&

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

$$