Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 250544 AAB
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1244 AM CDT FRI APR 25 2014

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

&&

.AVIATION...MOISTURE POOLING ACROSS THE REGION AS WINDS TURN ESE
WITH A WEAKENING FRONT ACROSS CENTRAL TEXAS. MVFR TO IFR CIGS AND
TEMPO MVFR VSBY WITH PATCHY FOG EXPECTED OVERNIGHT THROUGH A FEW
HOURS AFTER SUNRISE. DAYTIME HEATING TO ALLOW FOR DRY AIR ABOVE A
SURFACE INVERSION AOB 2000 FEET TO MIX TO THE SURFACE BREAKING UP
THE OVERCAST SKIES AND LIFTING CEILINGS. EXPECTED VFR CONDITIONS
AROUND 18Z IF NOT EARLIER. WINDS TO REMAIN LIGHT ESE TO SE WINDS
ANY GUSTS REMAINING BELOW 20 KNOTS.

&&

.PREV DISCUSSION... /ISSUED 659 PM CDT THU APR 24 2014/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...VFR CONDITIONS EXPECTED THROUGH EARLY THIS EVENING
WITH SOUTHEAST WINDS DECREASING AFTER SUNSET. THE INVERSION WILL
TRAP MOISTURE AT THE SURFACE AND A BRING LOW CLOUD DECK ACROSS THE
AREA WITH MVFR CEILINGS POSSIBLE AROUND 03Z. LIGHTER WINDS AND
ABUNDANT MOISTURE WITH WILL ALLOW FOR WIDESPREAD FOG FORMATION
AFTER MIDNIGHT. IFR/LIFR CONDITIONS EXPECTED BETWEEN 8 AND 14Z
FRIDAY. CEILINGS AND VISIBILITIES SLOWLY BEGIN TO IMPROVE BY MID
MORNING WITH FULLY VFR CONDITIONS EXPECTED BY 19Z.

PREV DISCUSSION... /ISSUED 126 PM CDT THU APR 24 2014/

SHORT TERM /NOW THROUGH FRIDAY NIGHT/SOUTHEAST WINDS WILL REMAIN
BREEZE FOR THE NEXT FEW HOURS BEFORE THE PRESSURE GRADIENT WEAKENS
ACROSS SOUTH TEXAS AS THE DRY LINE MIXES DOWN DRY AIR ALOFT. EXPECT
WINDS TO WEAKEN AS THE DRY LINES MIGRATES EAST ALLOWING FOR LIGHTER
NORTHEAST WINDS TO ARRIVE. SE LIGHT AND VARIABLE WINDS RETURN THIS
EVENING WITH DRY LINE RETROGRADING WEST PULLING IN ABUNDANT MOISTURE
ACROSS THE CWA. LATEST PWAT VALUES PERCENT OF NORMAL SHOW AN OF 125
AND IT IS EXPECTED TO SURGE MORE MOISTURE INTO THE AREA TONIGHT.
THIS WILL ALLOW FAVORABLE CONDITIONS FOR FOG TO DEVELOP INLAND AND
SPREAD INTO THE COASTAL COUNTIES. EXPECT VISIBILITY TO DETERIORATE
AFTER MIDNIGHT AND DEGRADE THROUGH THE EARLY MORNING HOURS. LOW
TEMPERATURES WILL REAMING IN THE MID TO LOW 70S ACROSS MUCH OF THE
CWA.

BY MID MORNING FRIDAY...WINDS BEGIN TO INCREASE BTWN 10 TO 15 MPH
DIMINISHING FOG AND IMPROVING VISIBILITY ACROSS THE CWA. STRONG
CAPPING INVERSION AND SOUTHWEST FLOW ALOFT WILL HELP TEMPERATURES
INCREASE...ESPECIALLY IN THE WESTERN VALLEY WITH THE DRIER AIR
BEHIND THE DRY LINE. TEMPS WILL REACH THE UPPER 90S...WITH AREAS
ALONG THE COAST WITH READINGS IN THE 80S. DRY LINE RETROGRADES
INLAND OVERNIGHT PULLING MOISTURE WITH ONSHORE FLOW ACROSS THE
AREA. THIS WILL YIELD FOR MORE FOG DEVELOPMENT LATE FRIDAY NIGHT
INTO EARLY SATURDAY. ABUNDANT CLOUD COVER WILL KEEP TEMPS IN THE
MID TO LOW 70S.

LONG TERM /SATURDAY THROUGH WEDNESDAY/...A MID LEVEL SHORT WAVE
TROUGH AXIS WILL ROTATE ACROSS THE FOUR CORNERS ON SATURDAY...WITH
PRESSURE FALLS AND CYCLOGENESIS OVER THE CENTRAL HIGH PLAINS. THE
ENSUING TIGHTER PRESSURE GRADIENT WILL INCREASE SOUTHEAST WINDS OVER
DEEP SOUTH TX AND THE RIO GRANDE VALLEY INTO THE BREEZY AND POSSIBLY
WINDY CATEGORY ON SATURDAY. LOW LEVEL WINDS WILL VEER TO SOUTH AND
SOUTHWEST GOING UP IN THE BOUNDARY LAYER...SETTING UP SUBSIDENCE AND
WARM TEMPERATURES FROM THE 80S NEAR THE COAST TO NEAR 100 FAR WEST.
THESE TEMPS WILL BE SIGNIFICANTLY ABOVE NORMAL OUT WEST...BUT WITH
DEW POINTS IN THE 60S...HEAT INDEX VALUES SHOULD NOT INCH TOO MUCH
ABOVE THE CENTURY MARK IN ANY PARTICULAR SPOT.

A COLD FRONT WILL SWEEP ACROSS CENTRAL AND SOUTH CENTRAL TEXAS
SATURDAY NIGHT...BUT THE MAIN ENERGY WILL STAY NORTH OF THE CWA...
AND RIGHT NOW NO PRECIPITATION IS FORECAST. DRIER AIR WILL ALREADY
PRECEDE THE FRONT...LIMITING THE OVERALL CONVECTIVE POTENTIAL.
NONETHELESS THIS PERIOD LOOKS THE MOST SUSCEPTIBLE TO ROGUE CELLS
MOVING INTO THE AREA FROM THE NORTH. ONCE SUNDAY ARRIVES HOWEVER...
VERY DRY AIR WILL MOVE IN FROM THE WEST...WITH HOT...DRY WEATHER
FOR SUNDAY AND MONDAY. HIGH TEMPERATURES SUNDAY AND MONDAY WILL
RANGE FIVE TO FIFTEEN DEGREES ABOVE NORMAL FROM EAST TO WEST...BUT
RELATIVE HUMIDITY VALUES WILL BE LOW...IN THE TEENS OUT WEST...
LIMITING HEAT INDEX VALUES. FIRE WEATHER CONCERNS WILL ALSO BE
MUTED AS 20 FT WINDS WILL BE LIGHT FOR THE MOST PART.

THE INITIAL DRY AIR OVER THE WEEKEND WILL BE FOLLOWED BY A
STRONGER SURGE ON TUESDAY...WITH NORTH AND NORTHEAST WINDS AND
INCREASING CLOUDINESS. ONCE AGAIN PRECIPITATION WILL BE IN THE AREA
BUT NOW IT WILL REMAIN JUST TO THE SOUTH AND ALSO OFFSHORE. CAN
NOT RULE OUT A SHOWER OR TWO NORTH OF THE RIO GRANDE HOWEVER. THE
STORM SYSTEM OVER THE PLAINS WILL MOVE EAST ON TUESDAY AND HIGH
PRESSURE MOVING SOUTH OVER THE CWA WILL POOL MOISTURE AND TRIGGER
SHOWERS JUST TO THE SOUTH. SLIGHTLY COOLER TEMPERATURES WILL BE ON
TAP FOR WEDNESDAY WHICH...HOWEVER...WILL STILL BE NEAR NORMAL.

MARINE...
NOW THROUGH FRIDAY NIGHT...THE SOUTHEAST WINDS WILL REMAIN BELOW
15 KNOTS TODAY AS HIGH PRESSURE SHIFTS EASTWARD AHEAD OF THE UPPER
LEVEL TROUGH SHIFTING EAST. THE WINDS WILL CONTINUE TO LOWER OVER
NIGHT WITH AN ONSHORE FLOW. THIS WILL ALLOW FOR MOISTURE TO MOVE
INLAND AND FOG TO DEVELOP NEAR THE COASTAL COUNTIES. SEAS WILL
LOWER FROM 4 TO 2 FEET OVERNIGHT INTO FRIDAY. BY THE EVENING LIGHT
WINDS PREVAIL WITH WINDS SHIFTING TO THE SOUTHEAST OVERNIGHT WITH
LOW SEAS. NO SCEC OR SCA THROUGH THE SHORT TERM FORECAST.

SATURDAY THROUGH MONDAY...MID LEVEL RIDGING WILL BE ROOTED OVER
EAST TEXAS AND LOUISIANA...EXTENDING NORTH. A NEUTRAL TO NEGATIVE
TILT MID LEVEL TROUGH WILL DIG SOUTH INTO THE GREAT BASIN WITH
DOWNSTREAM PRESSURE FALLS OVER THE CENTRAL HIGH PLAINS. THE RESULT
WILL BE INCREASING SOUTHEAST WINDS ON SATURDAY...WITH BUILDING
SEAS. SMALL CRAFT EXERCISE CAUTION CONDITIONS LOOK LIKELY AS A
MINIMUM DURING THE DAY...WITH SOUTHEAST WINDS APPROACHING 20 KTS.
A LOW LEVEL JET WILL SFC...OR MIX DOWN...OVER THE WATERS SATURDAY
NIGHT...BUMPING GULF CONDITIONS UP INTO SMALL CRAFT ADVISORY
CONDITION TERRITORY. THE ADVERSE CONDITIONS WILL CONTINUE ON
SUNDAY WITH 20 KT SOUTH SOUTH EAST WINDS AND 5 TO 7 FEET WAVE
HEIGHTS. AN ADVISORY MAY ALSO BE NEEDED ON THE LAGUNA SUNDAY. A
FRONT WILL PUSH INTO THE AREA ON MONDAY...WITH A WEAKENING
PRESSURE GRADIENT OVER THE WATER AND ASSOCIATED LOWER WIND SPEEDS.
ENERGY WITH THE ASSOCIATED SYSTEM WILL BE WELL TO THE NORTH...
WITH LITTLE IMPACT FOR THE LOWER TEXAS COAST. HIGH PRESSURE WILL
FILL IN FROM THE WEST ON TUESDAY...WITH MARINE WINDS SHIFTING TO
NORTH AND NORTHEAST DURING THE DAY. THE GRADIENT OVER THE GULF
WILL TIGHTEN AS HIGH PRESSURE ARRIVES...WITH 20 KT NORTH WINDS
REQUIRING EXERCISE CAUTION CONDITIONS AND POSSIBLY A SMALL CRAFT
ADVISORY TUESDAY AFTERNOON AND NIGHT.

&&

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

$$

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

59...AVIATION/SHORT TERM





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