FXUS64 KBRO 200854
AFDBRO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
354 AM CDT SAT SEP 20 2008
.DISCUSSION...LATEST IR SATELLITE IMAGERY SHOWS A BROAD AREA OF 
CLOUDINESS EXTENDING FROM SOUTHERN TAMAULIPAS TO THE PANHANDLE OF
FLORIDA ASSOCIATED WITH THE FRONT THAT PASSED OVER DEEP SOUTH
TEXAS SEPTEMBER 15. CURRENT RADAR IMAGERY SHOWS SHOWERS AND 
THUNDERSTORMS DEVELOPING OFF THE COAST OF TAMAULIPAS IN MEXICO.
MOVEMENT OF THESE SHOWERS IS TOWARD THE SOUTHWEST. WINDS ARE LIGHT
AND NORTHERLY OVER DEEP SOUTH TEXAS. 
ALL MODELS KEEP MOST OF THE PRECIPITATION ASSOCIATED WITH THE OLD
FRONTAL ZONE OVER THE GULF WATERS AND OFF THE COAST FOR THE WEEKEND.
HOWEVER...AREAS NEAR THE COAST COULD SEE SOME SHOWERS AND ISOLATED
STORMS TUESDAY AND WEDNESDAY AND PERHAPS AGAIN BY THE END OF THE
COMING WEEK. UPDATED THE POPS TO REFLECT THIS. CONFIDENCE WITH
THIS FORECAST IS LOW DUE TO THE FACT THAT WE ARE AT THE BOUNDARY
OF DRY AIR FUNNELED INTO THE REGION FROM THE NORTH-NORTHEAST BY
THE HIGH PRESSURE TO THE NORTH. THE ATMOSPHERE ABOVE 500 MB IS
VERY DRY AND THE FLOW WESTERLY WHICH WILL REDUCE THE SPREAD OF THE
PRECIPITATION WESTWARD INTO OUR CWA. THE PREFERRED SOLUTION FOR
THE CURRENT WEATHER SITUATION IS A BLEND OF THE GFS AND THE NAM.
THE ECMWF MODEL IS BELIEVED TO BE TOO WET WITH THE DEVELOPMENT OF
PRECIPITATION OVER THE TROPICAL OCEAN AS THE GULF OF MEXICO. IN
THE MEANTIME THE WEEKEND IS EXPECTED TO BE DRY WITH SOME PERIODS
OF CLOUDY SKIES AND HAZY CONDITIONS ESPECIALLY NEAR THE COAST.
LIGHT PATCHY FOG CAN OCCUR NEAR THE GROUND DUE TO RADIATIONAL
COOLING MAINLY A FEW MILES INLAND FROM THE COAST.
&&
.MARINE...CURRENTLY BUOY020 REPORTS A NORTHEAST WIND AROUND 10 KTS 
WITH LIGHT SWELLS AROUND 2.5 FT. MTRPIL CURRENTLY REPORTS A LIGHT 
NORTH WIND WITH LIGHT FOG. KBRO RADAR SHOWS SCT TO NUMEROUS CONV 
FIRING OFFSHORE OF THE LOWER TX COASTLINE AND NORTHEAST MEXICO IN 
THE LOW LEVEL SURFACE CONVERGENCE ASSOCIATED WITH A BROAD SURFACE 
TROUGH LINGERING OVER THE WESTERN GULF WATERS. THIS ACTIVITY IS 
MOVING SOUTHWEST AT AROUND 5 TO 10 MPH AND MAY SKIRT THE LOWER TX 
BAY AND GULF WATERS TODAY. SO WILL MAINTAIN THE MENTION OF POPS FOR 
THE FIRST PERIOD OF THE CWF TO ACCOUNT FOR THIS. THIS SURFACE TROUGH 
WILL LIKELY MEANDER OVER THE WESTERN GULF WATERS OVER THE NEXT 
COUPLE OF DAYS MAINTAINING THE THREAT FOR MARINE CONV FOR MOST OF 
THE CWF TIME PERIOD. THE PGF AND ASSOCIATED SWELL LEVELS WILL BE 
HIGHLY DEPENDENT ON THE LEVEL OF DEVELOPMENT OF THE SURFACE TROFFING 
OVER THE GULF OF MEX. THE ECMWF KEEPS SOME TYPE OF BROAD CLOSED LOW 
OVER THE SOUTHWESTERN GULF AND THE YUCATAN PENINSULA TOWARDS THE END 
OF NEXT WEEK WITH THIS FEATURE EVENTUALLY MOVING OUT TO THE N-NE BY 
NEXT WEEKEND. THE GFS DOES NOT REFLECT THE SAME LEVEL OF 
CYCLOGENESIS IN THE GULF LATER NEXT WITH ONLY PERSISTENT WEAK TO 
MODERATE SURFACE TROFFING PERSISTING. THE GWW SWELL GUIDANCE BUILDS 
SWELLS PRETTY QUICKLY LATE NEXT WEEK ACROSS MAINLY THE NORTHERN HALF 
OF THE GULF. CONSIDERING THE DEGREE OF UNCERTAINTY IN THE WHERE AND 
WHEN OF THE SURFACE LOW FORMATION IN THE GULF...WILL UNDERCUT THE 
ANTICIPATED GWW SWELLS WITH A MORE CONSERVATIVE SWELL TREND IN THE 
LATER PERIODS OF THE CWF. 
&&
.AVIATION...IR SATL AND SURFACE OBS SHOWS SOME SCT-BKN MID AND UPPER 
LEVEL CLD DECKS AFFECTING THE LOWER RGV AIRPORTS THIS MORNING. 
ALSO...SOME PATCHY FOG HAS FORMED REDUCING VSBYS INTO THE 4 TO 6 NM 
RANGE AROUND THE REGION. THIS LIGHT FOG AND PATCHY CLD DECKS WILL 
LIKELY PERSIST THROUGHOUT THE MORNING HOURS WITH THE FOG DISSIPATING 
AFTER SUNRISE. OVERALL VFR CONDITIONS WILL LIKELY PREVAIL AROUND THE 
REGION THROUGHOUT THIS CURRENT TAF PERIOD. PATCHY FOG WILL BE 
POSSIBLE ONCE AGAIN EARLY SUN MORNING...BUT DO NOT EXPECT WIDESPREAD 
REDUCTIONS IN VSBYS AT THIS TIME. 
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  88  73  88  74 /  30  10  10   0 
BROWNSVILLE          88  72  90  72 /  30  20  10  10 
HARLINGEN            90  72  91  71 /  20  10  10   0 
MCALLEN              92  71  92  72 /  20  10  10   0 
RIO GRANDE CITY      93  68  94  71 /  10  10   0   0 
SOUTH PADRE ISLAND   86  76  88  76 /  30  20  20  10 
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
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