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000
FXUS64 KBRO 101728 AAC
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1228 PM CDT MON MAR 10 2014

.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

&&

.AVIATION...LOW CIGS AND PATCHY FOG WILL KEEP UP THROUGH THE
AFTERNOON AND LIKELY THE OVERNIGHT HOURS AS WELL. SOME WINDOW FOR
IMPROVEMENT TO IFR FROM LIFR AT THE VALLEY SITES THROUGH MID
AFTERNOON BUT THAT IMPROVEMENT IS EXPECTED TO BE SHORT LIVED. AN
AREA OF DEVELOPING CONVECTION OVER MEXICO IS EXPECTED TO MOVE
EASTWARD INTO THE AREA THROUGH LATE AFTERNOON AND EARLY EVENING
WITH THUNDER PROSPECTS HIGH ENOUGH TO INCLUDE IN TAFS. PREDOMINANT
LIFR CONDITIONS ARE EXPECTED THIS EVENING AND OVERNIGHT WITH CIGS
AROUND 300 TO 500 FT WITH VISIBILITY 1 TO 3 MILES AND POSSIBLY
DROPPING LOWER AROUND SUNRISE. A PUSH OF DRIER AIR FROM THE WEST
ARRIVES LATE IN THE NEW TAF PERIOD LIKELY BETWEEN 16 TO 18Z AND
BEGAN TO SHOW IMPROVING CONDITIONS DURING THAT TIME FRAME. /68-JGG/

&&

.PREV DISCUSSION... /ISSUED 919 AM CDT MON MAR 10 2014/

DISCUSSION...AN AREA OF HEAVIER AND MORE WIDESPREAD RAINFALL IS
MOVING EAST OF THE REGION...BUT LIGHT RAIN AND DRIZZLE FROM WEAK
FRONTAL OVERRUNNING SHOULD PERSIST AMID THICK LOW CLOUD COVER FOR
THE NEXT SEVERAL HOURS. PATCHY LOCAL FOG IS ALSO DEVELOPING BUT
WIDESPREAD FOG ISSUES ARE NOT CURRENTLY ANTICIPATED. MAIN UPPER
LOW OVER MEXICO HAS BEGUN ITS EASTWARD TREK AND ANOTHER AREA OF
STRONG UPWARD MOTION IS EVIDENT OVER COAHULIA AND NUEVO LEON AND
SHOULD ARRIVE AROUND 3 TO 4 PM IN OUR WESTERN ZONES MOVING EAST
ACROSS THE AREA THROUGH THE EARLY EVENING. THIS SHOULD RESULT IN
INCREASED COVERAGE OF MORE MODERATE TO HEAVY SHOWERS WITH EMBEDDED
THUNDERSTORMS AT THAT TIME...WHICH REFLECTS THE GOING FORECAST.
TEMPERATURES ALSO LOOK ON TARGET HELD CLOSE TO CURRENT VALUES
THROUGH THE DAY DUE TO THICK CLOUD COVER AND COLD ADVECTION.
COASTAL TROUGHING APPEARS TO BE AT ABOUT THE SAME INTENSITY BASED
ON AN 04Z ASCAT PASS COUPLED WITH MORE RECENT BUOY
OBSERVATIONS...THAT SHOULD HOLD UNTIL THE UPPER TROUGH GETS
OVERHEAD LATE TONIGHT. /68-JGG/

PREV DISCUSSION... /ISSUED 617 AM CDT MON MAR 10 2014/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...PREDOMINANTLY IFR THROUGH THIS PERIOD WITH BRIEF
PERIODS OF MVFR FROM TIME TO TIME AT THE TAF SITES WITH MAINLY
NORTHWESTERLY WINDS. FOR PRECIPITATION...RADAR INDICATES LIGHT TO
MODERATE RAIN OVER THE LOWER VALLEY /KBRO AND KHRL/ ATTM. EXPECT A
LULL IN THE PRECIPITATION LATER THIS MORNING WITH PRECIPITATION
INCREASING THIS AFTERNOON AS AN UPPER LEVEL LOW PRESSURE
APPROACHES THE REGION FROM NORTHERN MEXICO. THUNDERSTORMS WILL BE
POSSIBLE THIS AFTERNOON AS WELL BUT COVERAGE APPEARS LIMITED AND
MENTIONED AS VCTS IN THE TAFS. EXPECT PRECIPITATION TO END AROUND
MID EVENING WITH REDUCTIONS IN VISIBILITIES EXPECTED THROUGHOUT
THE NIGHT.

PREV DISCUSSION... /ISSUED 343 AM CDT MON MAR 10 2014/

SHORT TERM /NOW THROUGH MONDAY NIGHT/...LEAD SHORTWAVE ASSOCIATED
WITH THE UPPER LEVEL LOW TO OUR WEST...COUPLED WITH DIFFLUENCE ALOFT
AND ISENTROPIC LIFT...HAS LED TO SHOWERS DEVELOPING ACROSS
TAMAULIPAS AND NUEVO LEON INTO DEEP SOUTH TEXAS WITH A BULK OF THE
PRECIPITATION EARLY THIS MORNING SITUATED TO OUR SOUTH WHERE THE
BEST DIFFLUENCE IS LOCATED. ISOLATED SHOWERS CONTINUE TO DEVELOP
OVER OUR AREA AND SHOULD BE THE CASE THROUGH THE MORNING HOURS.
TEMPERATURES ARE FAIRLY STEADY IN THE UPPER 40S TO LOWER 50S.

LEAD SHORTWAVE WILL CONTINUE EASTWARD THROUGH THE MORNING HOURS AND
BELIEVE THERE WILL BE A LULL IN THE PRECIPITATION LATER THIS MORNING
AND EARLY AFTERNOON. AS THE UPPER LOW IS PROGGED TO ADVANCE
NORTHEASTWARD THROUGH THE MORNING HOURS...THIS WILL PLACE THE
GREATEST AREA OF DIFFLUENCE OVER OUR AREA AROUND MID AFTERNOON.
ADJUSTED POPS DOWNWARD A LITTLE 14-20Z TO SHOW THE LULL THEN BUMPED
BACK UP TO CATEGORICAL HWY 281 EASTWARD AFT 20Z. HIGHS NOT EXPECTED
TO MOVE MUCH TODAY SO LEFT MID 50S AREAWIDE FOR HIGHS TODAY UNDER
CLOUDY SKIES.

AS THE LOW MOVES INTO CENTRAL TEXAS TONIGHT...DOWNGLIDE COMMENCES
ACROSS THE WEST THIS EVENING THEN SPREAD FROM WEST TO EAST OVERNIGHT
AS DRIER AIR FILTERS IN ON THE BACKSIDE OF THE LOW. POP CHANCES
DECREASE FROM WEST TO EAST OVERNIGHT AS WELL WITH THE BULK OF THE
CHANCES OVER THE COASTAL WATERS AFTER MIDNIGHT. WITH EXPECTED CLOUD
COVER...BUMPED LOWS UP A LITTLE BIT...EXPECT LOWER TO MIDDLE 50S
ACROSS THE AREA.

CLOUDS WILL DECREASE RAPIDLY FROM WEST TO EAST TUESDAY AS LARGE
SCALE SUBSIDENCE AND DRIER AIR WORKS INTO THE REGION ON
NORTHWESTERLY FLOW ALOFT. ANY SHOWER ACTIVITY EARLY TUESDAY MORNING
WILL BE RELEGATED TO THE FAR OFFSHORE WATERS. WITH ABUNDANT SUNSHINE
BY EARLY AFTERNOON...HIGHS WILL REACH THE UPPER 70S TO MIDDLE 80S.
SURFACE WINDS WILL BE FAIRLY LIGHT AND BACK TO THE SOUTH BY DAYS END....

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...A PROGRESSIVE MID LEVEL
FLOW REMAINS IN PLACE ACROSS NORTH AMERICA AS WE APPROACH THE
SPRING EQUINOX. THIS SHOULD RESULT IN TWO COLD FRONTS MOVING
THROUGH THE REGION THIS PERIOD. MODELS ARE IN GOOD AGREEMENT WITH
THE 500MB FLOW THROUGH SATURDAY MAKING FOR A FAIRLY HIGH
CONFIDENCE FORECAST MUCH OF THE WEEK. THEN MODELS DIVERGE SUNDAY
INTO MONDAY LOWERING CONFIDENCE AT THE END OF THE PACKAGE.

SHORTWAVE RIDGE TUESDAY NIGHT IN WAKE OF THE UPPER TROUGH TO PASS
TO THE EAST. MUCH OF THE LIFT AND RAIN SHOULD BE WELL EAST OF
SOUTH TEXAS WITH SOME LINGER RAIN ACROSS THE COASTAL WATERS.
TEMPERATURES COOL OFF NICELY WITH CLEARING SKIES AND DRIER
CONDITIONS. THE FIRST OF TWO COLD FRONTS SURGES THROUGH WEDNESDAY
MORNING AS STRONG SHORTWAVE DIVES THROUGH THE CENTRAL PLAINS. THIS
FRONT CONTINUES TO TREND DRY WITH ALL THE MOISTURE GETTING SHUNTED
EAST WITH TUESDAY`S TROUGH. HOWEVER THIS FRONT WILL FEATURE SOME
WIND AND COOLER TEMPERATURES. DECENT GRADIENT TO DEVELOP BETWEEN A
1030MB HIGH OVER THE SOUTHERN PLAINS AND A DEEPENING LOW PRESSURE
AREA ACROSS THE MID ATLANTIC. NORTH WINDS 20-30 MPH WILL BE
WIDESPREAD THROUGH THE MORNING AND EARLY AFTERNOON BEFORE QUICKLY
DIMINISHING LATE WED AFTERNOON AND EVENING AS THE SURFACE HIGH
MOVES INTO THE RGV. THIS SETS UP A CHILLY WED NIGHT AND THURSDAY
MORNING AS GOOD RADIATIONAL COOLING ALLOWS TEMPS TO FALL AS MUCH
AS 10 DEGREE BELOW NORMAL.

NEAR PERFECT DAY THURSDAY WITH MUCH LIGHTER WINDS AND COMFORTABLE
TEMPERATURES WITH PLENTY OF SUNSHINE. SURFACE RIDGE HEADS EAST
THURSDAY NIGHT AND FRIDAY WITH A WARMING AND MOISTENING TREND
COMMENCING. PREVIOUS FORECAST REMAINS UNCHANGED TRENDING WITH
INCREASING TEMPERATURES, HUMIDITY AND CLOUD COVER. AS WE MOVE INTO
THE WEEKEND...FORECAST BECOMES MORE UNCERTAIN AS MODELS CONTINUE
TO ADVERTISE THE MID LEVEL FLOW BECOMING INCREASING AMPLIFIED.
INITIALLY THIS WILL WARM US UP EVEN MORE SATURDAY AND SUNDAY AS A
TROUGH IS PROGGED TO DEEPEN OUT WEST. GFS/ECMWF SOLUTIONS CONTINUE
TO DIFFER ON PLACEMENT AND TIMING OF THE NEXT TROUGH. CURRENT FORECAST
MAINTAINS THE CHANCE OF RAIN LATE NEXT WEEKEND WITH PLENTY OF
ROOM FOR FINE TUNING AS WE GO THROUGH THE WEEK.

MARINE...NOW THROUGH TUESDAY...SMALL CRAFT SHOULD EXERCISE CAUTION
ACROSS THE COASTAL WATERS THIS MORNING. MODERATE WINDS AND SEAS
WILL RULE TODAY WITH AN OVERALL WEAKENING TREND IN THE WINDS AND
SLOWLY FALLING SEAS TONIGHT AND TUESDAY. SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE POSSIBLE TODAY THROUGH TONIGHT WITH DRIER
AIR WORKING INTO THE REGION TUESDAY CLOUDS WILL DECREASE AND RAIN
CHANCES WILL END.

TUESDAY NIGHT THROUGH FRIDAY...WEDNESDAY LOOKS LIKE A ROUGH
MARINE DAY AS A COLD FRONT SWEEPS THROUGH AROUND NOON. NORTH WINDS
AND SEAS TO QUICKLY INCREASE WITH SMALL CRAFT ADVISORIES STILL
LOOKING LIKELY. CONDITIONS IMPROVE THURSDAY AS FAST AS THEY
DEVELOPED AS HIGH PRESSURE BUILDS OVERHEAD. WINDS RETURN FROM THE
SOUTHEAST FRIDAY WITH SURFACE RIDGE EDGING EAST.

&&

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

$$

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