127  
FXUS64 KBRO 242356  
AFDBRO  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE BROWNSVILLE TX  
656 PM CDT FRI MAR 24 2017  
   
DISCUSSION
 
UPDATED FOR LATEST AVIATION DISCUSSION BELOW.  
 

 
   
AVIATION
 
GUSTY SOUTH TO SOUTHEAST WINDS WILL CONTINUE OVER THE  
NEXT COUPLE OF HOURS BEFORE DECOUPLING SHORTLY AFTER SUNSET. THE  
STRONG GRADIENT IS EXPECTED TO LESSEN OVERNIGHT AS THE STORM  
SYSTEM ACROSS OKLAHOMA MOVES EAST TOWARDS THE OHIO RIVER VALLEY.  
MEANWHILE, WEAK SURFACE TROUGHING WILL SET UP OVER THE REGION ON  
SATURDAY WITH WINDS MUCH LIGHTER BY COMPARISON. LOW LEVEL MOISTURE  
IS LOWER GIVEN THE DRY AIR THAT HAS MOVED INTO THE REGION, AND  
ALTHOUGH LOW CLOUDS COULD FORM, VFR CONDITIONS SHOULD PREVAIL  
THROUGH THE PERIOD.  
 

 
   
PREV DISCUSSION
 
/ISSUED 253 PM CDT FRI MAR 24 2017/  
 
SHORT TERM (NOW THROUGH SATURDAY NIGHT): LOW PRESSURE AREA  
CONTINUES TO SWEEP ACROSS THE TEXAS, PUSHING A WEAK COLD FRONT OUT  
AHEAD OF IT. PREFRONTAL TROUGH IN OUR REGION HAS SLOWLY DECREASED  
WINDS, AND IS STARTING TO BRING DRIER AIR AND HEATING INTO THE  
WESTERN VALLEY. CAPPING HAS KEPT THE SHOWER ACTIVITY WELL TO THE  
NORTH OF OUR AREA AS EXPECTED, AND WILL KEEP THINGS STABLE THROUGH  
THE NEXT 36 HOURS. WEAK H5 RIDGING SETS UP FOR TOMORROW BEHIND  
TODAY'S TROUGH, WHILE MORE DRY AIR DRAWS INTO THE WESTERN VALLEY  
DURING THE DAY. HIGHS WILL REACH THE LOW TO MID 90S OUT WEST IN  
THE DRIER AIR, WHILE THE WESTERN VALLEY REMAINS IN THE UPPER 80S  
IN THE MORE HUMID REGIME.  
 
LONG TERM (SUNDAY THROUGH FRIDAY): THE NEXT IN A SERIES OF SHORT  
WAVE TROUGHS WILL MOVE OUT OVER THE SOUTHERN PLAINS ON SUNDAY;  
UPSTREAM PRESSURE FALLS WILL BE ENOUGH TO SUPPORT LOCALLY  
STRONGER WINDS, BUT THERE WON'T BE ENOUGH PUSH TO GET A FRONT  
PAST THE DRY LINE IN WEST CENTRAL TEXAS. MID LEVEL RIDGING WILL  
TAKE HOLD OVER THE PLAINS AGAIN ON MONDAY IN THE UP UNTIL NOW  
RAPIDLY EVOLVING MID LEVEL PATTERN ACROSS THE SOUTHERN UNITED  
STATES.  
 
A MORE INTERESTING AND DEEPER TROUGH WILL DIVE DOWN THE WEST  
COAST MONDAY INTO TUESDAY, BOTTOMING OUT AS A MID LEVEL LOW OVER  
THE FOUR CORNERS ON TUESDAY AND WEDNESDAY. THIS WILL BRING SPOKES  
OF ENERGY AND UPPER PACIFIC MOISTURE OVER THE SIERRA MADRES OF  
MEXICO AND MAINLY INTO CENTRAL TEXAS ON WEDNESDAY, WITH THE LOW  
SINKING INTO NEW MEXICO. THE LOW WILL EJECT EAST WEDNESDAY, WITH  
STRONGER WEATHER AHEAD OF IT. THE PROGRESSION IS A LITTLE FASTER  
THAN IT WAS 24 HOURS AGO, BUT A FRONT WILL STILL TRY TO PUSH  
THROUGH ON THURSDAY. THE GFS HAS A LITTLE BIT OF ENERGY ALOFT IN  
THE TROUGH AXIS, BUT THE FORECAST SOUNDING LOOKS CAPPED THURSDAY  
MORNING AND VERY DRY AIR WILL ACCOMPANY THE WIND SHIFT, WITH PWAT  
DROPPING BY HALF AN INCH TO AROUND HALF AN INCH AND LEAVING LITTLE  
ELSE TO WORK WITH AT THE SURFACE. RELATIVE HUMIDITY VALUES WILL  
PLUMMET THURSDAY WITH THE ARRIVAL OF THE DRIER AIR, AND WILL  
REMAIN DEPRESSED ON FRIDAY, RESULTING IN A DRY HEAT. MODEL  
GUIDANCE IS ADVERTISING HIGHS WELL INTO THE 90S ON WEDNESDAY  
AHEAD OF THE FRONT, EVEN NEAR THE CENTURY MARK FOR MFE, THOUGH  
STILL HEDGED A LITTLE LOWER IN THE FORECAST FOR NOW. TO SUM UP:  
WARM, BREEZY AND DRY FOR MUCH OF THE LONG TERM.  
 
MARINE:  
NOW THROUGH SATURDAY NIGHT: WINDS HAVE DROPPED OFF OFFSHORE THUS  
AFTERNOON AS THE SFC WIND DECOUPLE FROM THE LLVL JET, BUT CONTINUE  
TO RACE NORTHWARD CLOSER TO SHORE. SEAS REMAIN AGITATED, RUNNING 8  
TO 10 FEET OFFSHORE AND 6 TO 7 FEET CLOSE TO SHORE. SMALL CRAFT  
ADVISORIES REMAIN IN EFFECT FOR THE GULF WATERS THROUGH AT LEAST  
7PM FOR ALL ZONES, AND MAY NEED TO BE EXTENDED FOR THE GULF WATERS  
IF SEAS DON'T RELAX AS QUICKLY AS FORECAST. BETTER MARINE  
CONDITIONS FORECAST TOMORROW AS HIGH PRESSURE BRIEFLY MOVES ACROSS  
THE NORTHWEST GULF. WINDS WILL REMAIN 10 TO 15 KNOTS, WHICH WILL  
ALLOW SEAS TO DROP TO 4 TO 5 FEET. SEAS REMAIN AGITATED SATURDAY  
NIGHT AND SOUTHEAST WINDS REESTABLISH AND BEGIN TO RISE.  
 
SUNDAY THROUGH WEDNESDAY: PRESSURE WILL DECREASE OVER THE PLAINS  
SATURDAY, RESULTING IN STRONGER SOUTHEAST WINDS LATE SATURDAY INTO  
SUNDAY AND SUNDAY NIGHT. SEAS WILL BUILD BY SUNDAY UNDER FRESH  
SOUTHEAST WINDS. WINDS AND SEAS WILL IMPROVE MONDAY AND MONDAY  
NIGHT AS THE NEXT RIDGE MOVES INTO THE PLAINS. A VIGOROUS SHORT  
WAVE/CUT OFF LOW WILL MOVE INTO THE FOUR CORNERS REGION TUESDAY.  
SOUTHEAST WINDS WILL SUBSEQUENTLY RAMP UP TO ABOVE 20 KNOTS ON  
THE GULF TUESDAY THROUGH WEDNESDAY, WITH NEAR 20 KNOTS ON THE  
LAGUNA MADRE ALSO. WAVE HEIGHTS WILL BUILD TO BETWEEN 6 AND 8  
FEET OFFSHORE LATE TUESDAY NIGHT INTO WEDNESDAY. HENCE, EXCEPT  
FOR A BRIEF IMPROVEMENT MONDAY INTO MONDAY NIGHT, MARINE  
CONDITIONS WILL NOT BE IDEAL, WITH SMALL CRAFT EXERCISE CAUTION  
TO SMALL CRAFT ADVISORY CONDITIONS A POSSIBILITY MUCH OF THE  
TIME.  
 

 
   
BRO WATCHES/WARNINGS/ADVISORIES
 
 
TX...NONE.  
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM CDT THIS EVENING FOR  
GMZ130-132-135.  
 
SMALL CRAFT ADVISORY UNTIL 1 AM CDT SATURDAY FOR GMZ150-155-170-  
175.  
 

 
 

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