000 FXUS64 KBRO 160737 AFDBRO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 237 AM CDT FRI MAY 16 2008 .DISCUSSION... MULTIPLE FACTORS COMING TOGETHER TO PRODUCE SHOWERS AND THUNDERSTORMS FOR DEEP SOUTH TEXAS TODAY. LAST NIGHTS SOUNDING SHOWED PW OF 2.09 INCHES WITH ABSOLUTELY NO CAPPING INVERSION PRESENT...CAPE OF 3700..AND TT OF 50. ATMOSPHERE VERY UNSTABLE WITH DEWPOINTS IN THE UPPER 70S. COLD FRONT CURRENTLY MOSEYING SOUTHWARD JUST NORTH OF THE RIVER...NOT CURRENTLY PROVIDING FOCUS FOR SHOWERS ITSELF. MIDLEVEL SHORTWAVE SWEEPING THROUGH SOUTH TEXAS SPARKING SHOWERS AND THUNDERSTORMS OVER THE WESTERN CWA AND ABOUT 100 MILES SOUTH OF BROWNSVILLE. RAIN WILL CONTINUE TO SPREAD EASTWARD THROUGH THE REST OF THE CWA TONIGHT...WITH AREAS OF HEAVY RAIN BEING THE BIGGEST THREAT. SOME STRONG TO SEVERE THUNDERSTORMS ARE STILL EXPECTED...WITH SOME HAIL AND HIGH WINDS AGAIN THREATENING. MODELS DO INDICATE THAT CONDITIONS WILL IMPROVE FOR THIS AFTERNOON...BUT ANOTHER MIDLEVEL VORT TONIGHT ALONG WITH CONTINUED SATURATED ATMOSPHERE WILL BRING ANOTHER CHANCE FOR RAIN TONIGHT. MOST OF THE STRONGER ACTIVITY TONIGHT WILL BE HELD FURTHER SOUTH IN MEXICO SOUTH OF THE FRONT. PRECIPITATION CHANCES WILL NOT DIMINISH PROBABLY UNTIL MONDAY WHEN SATURATED ATMOSPHERE IS FINALLY FORCED BACK OUT TO SEA BY NORTHWEST WINDS ALOFT. TEMPERATURES TODAY AND TOMORROW WILL BE ABOUT 5 DEGREES BELOW NORMAL...BUT THIS IS DUE TO THE OVERCAST SKIES EXPECTED ALL DAY AND NOT FROM ANY TEMPERATURE DIFFERENCES BEHIND THE FRONT. LOWS WILL ALSO BE ABOUT 5 DEGREES BELOW NORMAL. TEMPERATURES RETURN TO NORMAL STARTING SUNDAY WITH BREAKS IN THE CLOUD COVER...WITH ABOVE NORMAL TEMPS RETURNING FOR EARLY NEXT WEEK AFTER MOISTURE DEPARTS. && .AVIATION... SHOWERS AND THUNDERSTORMS WILL PLAGUE DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY OVER THE NEXT 24 HOURS. FLYING CONDITIONS WILL BE HIGHLY DEPENDENT ON THE ACTIVITY. WIDESPREAD ACTIVITY IS EXPECTED THIS MORNING AND SLOWLY TAPERING OFF THROUGH THE AFTERNOON. ISOLATED SEVERE STORMS WITH OCCASIONAL TO FREQUENT LIGHTNING AND TORRENTIAL DOWNPOURS ARE POSSIBLE. && .MARINE... A SMALL CRAFT ADVISORY WILL BE POSTED FOR THE OFFSHORE WATERS TODAY AS COLD FRONT MOVES THROUGH THE COASTAL WATERS. WINDS SHIFT TO THE NORTHEAST AND SEAS BUILD THROUGH THE DAY. OTHER CONCERNS WILL BE NUMEROUS SHOWERS AND THUNDERSTORMS IN ADVANCE AND BEHIND THE FRONT. NORTHEAST WINDS TO DIMINISH TONIGHT WITH SEAS SLOW TO SUBSIDE. THE NORTHEAST FLOW IS TO PERSIST THROUGH SATURDAY AND SLOWLY VEER EAST TO SOUTHEAST SUNDAY AND MONDAY. RAIN CHANCES REMAIN GOOD SATURDAY AND SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 80 68 80 66 / 80 50 50 40 BROWNSVILLE 82 66 82 66 / 80 50 50 40 HARLINGEN 81 64 82 65 / 80 50 50 40 MCALLEN 83 67 80 67 / 80 50 50 30 RIO GRANDE CITY 79 66 80 67 / 80 50 40 20 SOUTH PADRE ISLAND 81 70 78 67 / 80 50 50 40 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 6 PM CDT THIS AFTERNOON FOR GMZ150-155-170-175. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WWW.WEATHER.GOV/BROWNSVILLE 64/59