Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 252351 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
651 PM CDT SAT OCT 25 2014

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

&&

.AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING WITH
LIGHT EASTERLY WINDS. LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOG
TO DEVELOP AGAIN OVERNIGHT. THE CURRENT NAM/SREF INDICATES THAT
THE HIGHER PROBABILITY OF FOG WILL PREVAIL AT HRL/MFE AND ACROSS THE
NORTHERN RANCHLANDS. SO WILL CONTINUE TO MENTION PREDOMINANT
VISIBILITY OF 3SM FOR HRL AND MFE FROM 10-1430Z. THE PROBABILITY
IS LOWER AT BRO....WILL MAINTAIN THE TEMPO FOR 5SM FROM 10-14Z. VFR
CONDITIONS WILL PREVAIL AREA WIDE BY 15Z. LIGHT EAST WINDS TONIGHT
WILL BECOME SOUTHEAST OVERNIGHT. SOUTHEAST WINDS WILL INCREASE TO
AROUND 11 KNOTS BY LATE AFTERNOON.

&&

.PREV DISCUSSION... /ISSUED 311 PM CDT SAT OCT 25 2014/

SHORT TERM /NOW THROUGH SUNDAY NIGHT/...DOMINATING 500MB HIGH
PRESSURE ACROSS WEST TEXAS WILL SAG SOUTHEASTWARD AND WEAKEN AS A
STRONG S/W TROUGH MOVES ACROSS THE NORTHERN ROCKIES AND SUPPORTS A
FRONTAL SYSTEM INTO THE CENTRAL PLAINS BY SUNDAY NIGHT. SFC HIGH
PRESSURE WILL ALSO MOVE EASTWARD WHICH WILL ALLOW WINDS TO SWING TO
THE SOUTHEAST SUNDAY. WINDS WILL BECOME NEARLY CALM TONIGHT WHICH
WILL ALLOW FOG TO FORM IN THE PREDAWN HOURS ACROSS THE CENTRAL AND
EASTERN PORTIONS OF THE AREA. ALTHOUGH NOT EXPECTING WIDESPREAD
DENSE FOG...AREAS OF FOG WILL BE POSSIBLE WITH THE OCCASIONAL
VISIBILITY DROPPING TO AROUND A MILE. FOG WILL BURN OFF BY 10 AM
ALLOWING ANOTHER NICE DAY TO WRAP UP THIS WONDERFUL WEEKEND. HIGHS
WILL BE SIMILAR TO TODAY WITH LOWS TONIGHT IN THE LOWER TO MIDDLE
60S.

LONG TERM /MONDAY THROUGH SATURDAY/...THE 500 MB RIDGING IN PLACE
OVER THE SOUTH CENTRAL PLAINS STATES AND NORTHERN MEXICO WILL BE
WEAKENING AS BROAD TROFFING DIGS INTO THE WESTERN AND CENTRAL STATES 
INTO THE FIRST HALF OF NEXT WEEK. AS THIS TROFFING PUSHES EAST IT
WILL DRAG A COLD FRONT INTO THE CENTRAL PORTIONS OF TX TUES AND WED
WITH THIS WEAK SURFACE BOUNDARY SAGGING SLOWLY TOWARDS THE TX
COASTLINE. 500 MB RIDGING THEN BUILDS BACK IN PLACE TO OUR WEST
OVER MEXICO AND THE DESERT SW THURS WHILE THE BROAD MID LEVEL
TROFFING DIGS ACROSS THE EASTERN STATES THURS AND FRI. THIS WILL
EVENTUALLY DRIVE A FAIRLY DRY COLD FRONT THROUGH THE REGION LATE
THURS. VERY LIMITED MOISTURE WILL LIKELY POOL AHEAD OF THIS FRONT
AND WILL ACCORDINGLY MAINTAIN ONLY SOME SLGT CHC POPS FOR THURS
AND FRI. A FAIRLY MILDER N-NE SURFACE FLOW WILL THEN PREVAIL THURS
NIGHT THROUGH SAT WHICH WILL LOWER THE OVERALL TEMPS DOWN CLOSER
TO CLIMO FOR THE END OF OCTOBER. AHEAD OF THIS FROPA TEMPS WILL
REMAIN WELL ABOVE CLIMO FOR LATE OCT AS LOW LEVEL WAA WILL PREVAIL
EARLY NEXT WEEK WITH DECENT SUNSHINE MAINTAINING GOOD DIURNAL
HEATING.

THE GFS AND ECMWF MODELS ARE IN PRETTY GOOD AGREEMENT THROUGH DAY
7 IN THE OVERALL PLACEMENT OF THE BROAD SYNOPTIC FEATURES ACROSS
THE LOWER 48 STATES. THE BIGGEST DIFFERENCES SHOW UP BETWEEN THE
TWO MODELS IN THE HANDLING OF THE DIGGING EAST COAST 500 MB
TROFFING WITH THE ECMWF SHOWING A MORE SOUTHWARDS TROUGH/CLOSED
LOW OVER THE EASTERN STATES. OVERALL FORECAST CONFIDENCE REMAINS
ABOVE AVERAGE FOR THE LONGER RANGE FORECAST WORDING DUE TO THE
GOOD MODEL AGREEMENT.

WILL GO AT OR A LITTLE ABOVE MODEL TEMP GUIDANCE FOR THE LONGER
RANGE PERIOD AND WILL STICK FAIRLY CLOSE TO MODEL POPS.

MARINE...NOW THROUGH SUNDAY NIGHT...SEAS WERE 2.5 FEET WITH NORTHEAST-EAST
WINDS NEAR 6 KNOTS AT BUOY020 EARLY THIS AFTERNOON. SURFACE HIGH
PRESSURE WILL SLIDE EASTWARD ALLOWING WINDS TO SWITCH TO THE
SOUTHEAST BEGINNING TONIGHT. LOW PRESSURE WILL DEVELOP ACROSS WEST
TEXAS SUNDAY WHICH WILL AID IN INCREASING WINDS AND SLIGHTLY HIGHER
SEAS SUNDAY NIGHT. SCEC IS POSSIBLE SUNDAY NIGHT.

MONDAY THROUGH THURSDAY...THE MARINE CONDITIONS MAY PUSH UP CLOSE
TO SCA LEVELS ON MON AS THE PGF TIGHTENS AHEAD OF A BROAD SURFACE
LOW PRESSURE SYSTEM MOVING ACROSS THE CENTRAL STATES. THE PGF WILL
THEN START TO WEAKEN SOMEWHAT AS THE SURFACE LOW SHIFTS OUT
FURTHER TO THE EAST. A FAIRLY LIGHT TO MODERATE SE-NE ONSHORE FLOW
WILL THEN PREVAIL FROM TUES THROUGH THURS WHICH WILL MAINTAIN THE
BAY AND GULF CONDITIONS BELOW SCA LEVELS.

&&

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

$$

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