FXUS64 KBRO 210803 AFDBRO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 303 AM CDT SUN MAR 21 2010 .SHORT TERM /TODAY THROUGH 7 PM MONDAY/...WIND FORECAST FOR TODAY WILL DRIVE SENSIBLE WEATHER CHANGES IN THE SHORT TERM. WINDS OFF THE SURFACE 40 TO 50 KTS THIS MORNING WILL MIX DOWNWARD QUICKLY AFTER SUNRISE KEEPING BREEZY CONDITIONS UP THROUGH AT LEAST EARLY AFTERNOON AND ALLOWING DRIER AIR TO MIX DOWN TODAY LOWERING DEWPOINTS FURTHER...PERHAPS INTO THE TEENS WESTERN COUNTIES. TEMPS WILL RESPOND NICELY IN THE DRY AIR TEMPERED ONLY BY THE WINDS. NAM/RUC HAVE SOLID HANDLE ON THE BOUNDARY LAYER WINDS AND DRIER AIR AND HAVE TWEAKED FORECAST WINDS TO REFLECT LATEST RUNS. ATMOSPHERE WILL DECOUPLE AFTER DARK ALLOWING WINDS TO GO CALM WITH EXCELLENT RADIATIONAL COOLING ON TAP. MIN TEMP RECORDS COULD BE IN DANGER MONDAY MORNING WITH LOWS EXPECTED NEAR 40 TO LOWER 40S..ONLY A FEW DEGREES ABOVE AREA RECORDS. SOUTHEASTERLY FLOW RETURNS LATE MONDAY HERALDING A SLOW MOISTURE AND TEMPERATURE RECOVERY FOR THE EARLY WEEK. && .LONG TERM /00Z TUESDAY THROUGH SUNDAY/...SURFACE HIGH PRESSURE SHIFTING INTO THE GULF AT THE BEGINNING OF THE PERIOD WILL OPEN UP SOUTHEAST FLOW ACROSS DEEP SOUTH TEXAS...PUTTING AN END TO THE BONE DRY CONDITIONS. NEXT IN A SERIES OF MIDLEVEL TROUGHS WILL SWEEP ACROSS THE SOUTHWESTERN US AND INTO TEXAS WEDNESDAY. A COUPLE VORT MAXIMA CAUGHT OUT AHEAD OF IT IN THE SOUTHWEST FLOW ALOFT WILL BRING A SLIGHT CHANCE FOR SHOWERS DURING THE DAY WEDNESDAY. FORECAST THINKING IS THAT MOST OF THIS ENERGY WILL REMAIN IN THE WESTERN VALLEY...WITH ONLY LIGHT RAIN/SPRINKLES FOR THE COASTAL REGIONS. MODELS BEGINNING TO AGREE ON BRINGING THE FRONT ASSOCIATED WITH THE MIDLEVEL TROUGH THROUGH DEEP SOUTH TEXAS DURING THE PREDAWN HOURS ON THURSDAY. MODELS ALSO BEGINNING TO SHOW CONSISTENCY WITH PUSHING THE FRONT WELL OUT TO SEA...WITH EVER HIGHER BREEZES WITH AND BEHIND THE FRONT. PRECIPITATION IS STILL A QUESTION MARK AS DYNAMICS ALOFT STILL LOOK WEAK AND WELL AWAY FROM DEEP SOUTH TEXAS. WILL KEEP ISOLATED POPS FOR THE REGION FOR IMMEDIATELY DURING FRONTAL PASSAGE THURSDAY...WITH QUICK CLEARING IN ITS WAKE. TEMPERATURES DURING THE EXTENDED PERIOD REMAIN CLOSE TO NORMALS FOR THIS TIME OF YEAR...WHICH IS RIGHT AROUND 80 FOR HIGHS AND 60 FOR LOWS. && .AVIATION... VFR THROUGH 12Z MONDAY. 50 KT FLOW AT 3000 FEET THIS MORNING WILL SUPPORT GUSTY WINDS BRIEFLY AFTER DAYBREAK. BREEZY NORTHERLY FLOW WILL DIMINISH SLOWLY THROUGH THE DAY TODAY WITH WINDS LIGHT AND VARIABLE SHORTLY AFTER 00Z AND CONTINUING OVERNIGHT. SOUTHEASTERLY FLOW WILL REDEVELOP ON MONDAY. && .MARINE... BUOYS GUSTING WELL OVER 30 KTS WITH SEAS ABOVE 11 FEET AT MIDNIGHT. WINDS SHOULD DECREASE SLOWLY THROUGH THE EARLY MORNING HOURS ALLOWING GALE WARNING FOR THE COASTAL WATERS TO EXPIRE ON TIME HOWEVER CONDITIONS WILL LIKELY REMAIN ABOVE SMALL CRAFT ADVISORY CRITERIA INTO THE EARLY AFTERNOON. CONDITIONS OVER THE LAGUNA MADRE STILL ABOVE SCA CRITERIA AND MAY NEED TO EXTEND A LITTLE LONGER THROUGH THE MORNING GIVEN EXPECTED DOWNWARD MOMENTUM. MARINE CONDITIONS WILL IMPROVE THROUGH THE AFTERNOON. AN ONSHORE FLOW WILL REDEVELOP MONDAY AFTERNOON...AND WILL CONTINUE INTO THE LATTER HALF OF THE WEEK. A COLD FRONT WILL MOVE THROUGH THE COASTAL WATERS LIKELY AROUND DAWN THURSDAY...SWITCHING WINDS TO THE NORTHWEST. STRENGTH OF THE NORTHWEST FLOW SURGE STILL A BIT QUESTIONABLE BUT STILL HAS A GOOD CHANCE TO REACH ADVISORY STRENGTH RIGHT AS IT PASSES. SEAS WILL REMAIN STEADY 2 TO 4 FEET UNTIL THE FRONTAL PASSAGE. && .FIRE WEATHER... VERY DRY AIR IN PLACE OVER THE RIO GRANDE VALLEY TODAY. SURFACE WINDS WHILE STILL BREEZY ESPECIALLY THIS MORNING WILL STAY BELOW RED FLAG CRITERIA. RELATIVE HUMIDITIES WILL BEGIN TO RECOVER LATE MONDAY AS A SOUTHEASTERLY FLOW REDEVELOPS. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 69 46 74 57 / 0 0 0 0 BROWNSVILLE 71 45 77 54 / 0 0 0 0 HARLINGEN 71 42 79 54 / 0 0 0 0 MCALLEN 73 41 81 55 / 0 0 0 0 RIO GRANDE CITY 74 45 83 56 / 0 0 0 0 SOUTH PADRE ISLAND 68 52 75 58 / 0 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR GMZ130-132- 135. GALE WARNING UNTIL 10 AM CDT THIS MORNING FOR GMZ150-155-170-175. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WWW.WEATHER.GOV/BROWNSVILLE 51/64