Area Forecast Discussion
Issued by NWS Brownsville, TX

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000
FXUS64 KBRO 300600 AAB
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
100 AM CDT MON MAR 30 2015

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

&&

.AVIATION...CURRENT BRO VWP INDICATES A STRONG SOUTHERLY LLJ AT
45 KNOTS EVIDENT JUST OFF OF THE SURFACE. SO WILL INCLUDE A
MENTION OF LLWS FOR BRO/HRL AND MFE TAFS THROUGH 15Z. VFR
CONDITIONS EXPECTED OVERNIGHT WITH SOME LOW CLOUD DECKS DEVELOPING
AROUND SUNRISE. WILL MENTION A TEMPO FOR MVFR CEILINGS BETWEEN
11-15Z AT ALL VALLEY TERMINALS. SOUTHEAST WINDS WILL PICK UP AFTER
15Z WITH GUSTS AROUND 25 KNOTS...ESPECIALLY IN THE AFTERNOON. VFR
CONDITIONS WILL PREVAIL BY LATE MONDAY MORNING THROUGH MONDAY
EVENING.

&&

.PREV DISCUSSION... /ISSUED 630 PM CDT SUN MAR 29 2015/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...STRONG WINDS CURRENTLY WILL BE SLOW TO SUBSIDE BUT
SHOULD FALL BELOW 12 KNOTS BY MID EVENING BUT AN INFREQUENT GUST
TO 20 KNOTS IS POSSIBLE AT ANYTIME THROUGH THE NIGHT. CONDITIONS
WILL REMAIN VFR OVERNIGHT WITH STRATUS AND PATCHY FOG BECOMING
POSSIBLE LATE IN THE OVERNIGHT HOURS NORTH OF THE VALLEY. VALLEY
TERMINALS WILL EXPERIENCE FEW-SCT AT 2000 FEET CLOSER TO DAWN.
WINDS WILL PICK BACK UP ON MONDAY BUT WILL NOT BE AS STRONG. TEMPO
MVFR AFTER DAWN THROUGH LATE MORNING AS CUMULUS FIELD DEVELOPS.

DISCUSSION...UPDATED FOR LATEST MARINE DISCUSSION BELOW.

MARINE...EXTENDED SMALL CRAFT ADVISORY FOR THE LAGUNA MADRE AND
NEARSHORE WATERS AS WINDS REAMIN AROUND 20 KNOTS SUSTAINED AND
GUSTS IN THE 25-30 KNOT RANGE.

PREV DISCUSSION... /ISSUED 250 PM CDT SUN MAR 29 2015/

SHORT TERM.../NOW THROUGH MONDAY NIGHT/...500 MB LEVEL RIDGE
OVER MEXICO AND WEST TEXAS WILL CONTINUE ITS TRAJECTORY EASTWARD
TODAY AND MONDAY AS A WEAK PERTURBATION ENTERS BAJA CA. THE LATEST
WATER VAPOR IMAGERY AND THE KBRO 12Z SOUNDING SHOW AN ABUNDANCE
OF DRIER AIR THROUGH THE COLUMN AND BREEZY SOUTH WINDS IN THE
LOWER LEVELS. IN THE LOWER LEVELS...THE COMBINATION OF A BROAD
HIGH ACROSS THE SOUTHEAST PLAINS AND LOW OVER WEST TEXAS WILL
STRENGTHEN THE PGF RIGHT ALONG THE COAST THE REMAINDER OF TODAY
WITH GUSTY WINDS UP 35 TO 40 MPH. THE WIND ADVISORY CONTINUES
THROUGH THE EVENING. A WEAK FRONT WILL MOVE FURTHER EASTWARD WITH
RIDGE BUILDING ACROSS THE SE REGION WHICH WILL WEAKEN THE GRADIENT
THIS EVENING AND INTO TONIGHT. DAYTIME HIGH TEMPS WILL REACH THE
LOW TO MID 80S. WARMEST LOCATIONS COULD SEE CLOSE TO 90S NEAR RIO
GRANDE CITY AND ZAPATA.

AS THE RIDGE GRADUALLY SHIFTS EAST OVER SOUTHERN REGION OF
TEXAS...HIGH PRESSURE OVER THE SE MOVES SOUTH KEEPING A SE FLOW
ACROSS THE AREA. AS THE INVERSION DEVELOPS THE SOUTHEAST FLOW WILL
ADVECT GULF MOISTURE IN THE LOWER LEVELS INCREASING CLOUD COVER
OVERNIGHT. SOME AREAS OF PATCHY FOG WILL BE POSSIBLE ALONG THE
NORTHERN RANCHLANDS WERE THE WINDS WILL BE LIGHT TO VARIABLE A
LOT SOONER THAN THE COAST. OVERNIGHT LOW TEMPERATURES WERE IN THE
MID TO UPPER 60S ACROSS THE CWA. CEILINGS COULD LOWER BETWEEN
2500 FEET TO 1500 FEET ESPECIALLY OVER THE LOWER RIO GRANDE
VALLEY WHERE THE ADVECTION WILL BE GREATER. THIS PATTERN WILL NOT
CHANGE MUCH BUT THE GRADIENT WILL NOT BE AS STRONG KEEPING WINDS
BELOW ADVISORY CRITERIA. GUSTY WINDS WILL BE POSSIBLE IN THE
AFTERNOON WITH PEAK HEATING BUT DO NOT EXPECT MORE THAN 20 TO 25
MPH AND DIMINISHING IN THE EVENING MONDAY. MONDAY NIGHT...
SOUTHEAST WINDS WILL REMAIN LIGHT THROUGH THE NIGHT WITH CLOUD
COVER PREVAILING AND TEMPERATURES STEADY IN THE MID TO UPPER 60S.

LONG TERM /TUESDAY THROUGH SATURDAY/...A MID LEVEL SHORTWAVE
TROUGH WILL MOVE EAST ACROSS NORTHERN MEXICO INTO THE BIG BEND AND
WEST TEXAS REGION TUESDAY...THEN ACROSS CENTRAL/SOUTHERN TEXAS
WEDNESDAY. RAIN CHANCES WILL INCREASE ON TUESDAY AS THE MID TO
UPPER LEVEL DISTURBANCE APPROACHES FROM THE WEST AND THE MID LEVEL
FLOW OVERHEAD SUPPORTS LIFT. WEAK RIGHT REAR JET ENTRANCE REGION
WILL ALSO PROVIDE SOME DIVERGENCE ALOFT...WHILE SURFACE DEW POINTS
IN THE 60S WILL NOT DETRACT FROM CONVECTION. THE BEST OPPORTUNITY
FOR SHOWERS AND THUNDERSTORMS WILL BE TUESDAY NIGHT ACROSS THE
WEST AND NORTH. THE GFS IS LESS ROBUST WITH THE IDEA OF CONVECTION
WITH THE DISTURBANCE THAN THE ECMWF...WHOSE GUIDANCE ADVERTISES
A 40 PERCENT CHANCE AT LRD TUESDAY NIGHT. OPTED TO GO A LITTLE
LESS FOR THE CWA WHILE BLENDING INOT THE HIGHER AMOUNTS SUGGESTED
TO THE NORTH.

RAIN CHANCES WILL END FROM WEST TO EAST ON WEDNESDAY WITH
CONVECTION LINGERING ACROSS THE GULF WATERS THROUGH WEDNESDAY
AFTERNOON. THE SHORTWAVE WILL MOVE EAST OF THE REGION ON THURSDAY
WITH A RATHER ZONAL MID LEVEL PATTERN TAKING OVER OR EVEN A WEAK
RIDGE BUILDING UP FROM THE SOUTH TOWARDS THE END OF THE WEEK.
LIGHT TO MODERATE SOUTHEAST WINDS AND SEASONAL TEMPERATURES WILL
PREVAIL THROUGH MUCH OF THE LONG TERM.

RAIN CHANCES WILL INCREASE AGAIN LATE FRIDAY NIGHT INTO SATURDAY
AS A PLAINS COLD FRONT MOVES INTO DEEP SOUTH TEXAS. HOWEVER...
THERE WILL BE LITTLE UPPER DYNAMICS TO WORK WITH...AND IT LOOKS
MORE LIKE A LIGHT RAIN/SHOWER EVENT AS THE HIGH PRESSURE PUSHES
SOUTH INTO THE FRONT RANGE OF MEXICO. A RUMBLE OF THUNDER MAY BE
POSSIBLE TO THE WEST OF THE UPPER VALLEY. HIGH TEMPS SATURDAY AND
SUNDAY WILL DROP INTO THE LOWER 70S...A NOTICEABLE CHANGE FROM THE
80S TO LOWER 90S OF FRIDAY...AND CLOUDY SKIES WILL REIGN NEXT
WEEKEND WITH LIGHT NORTHEAST WINDS ON SATURDAY BEFORE THE HIGH
PRESSURE SLIDES EAST AND WINDS VEER.

MARINE...
NOW THROUGH MONDAY NIGHT...SOUTHEAST WINDS WILL REMAIN BREEZY
THIS AFTERNOON AS THE GRADIENT REMAINS STRONG ALONG THE COAST.
THIS WILL MAINTAINS WINDS ABOVE 20 KNOTS THROUGH THE AFTERNOON. A
SCA FOR WINDS IS IN EFFECT UNTIL THIS EVENING. DUE TO THE SHORT
DURATION OF THE BREEZY CONDITIONS...SEAS WILL NOT REACH MORE THAN
5 FEET. TONIGHT...THE GRADIENT WILL WEAKEN...KEEPING A LIGHT TO
MODERATE SOUTHEAST WIND. NO SCA NEEDED BUT POSSIBLE SCEC FOR THE
OVERNIGHT. INTO MONDAY...SOUTHEAST FLOW WILL PREVAIL THROUGH THE
SHORT TERM BUT WILL BE LESS THAN WHAT WE HAVE TODAY WITH NO SCA.

TUESDAY THROUGH THURSDAY...WEAK RIDGING OVERHEAD WILL SUPPORT
SURFACE HIGH PRESSURE OVER THE NORTH GULF...RESULTING IN LIGHT TO
MODERATE SOUTHEAST WINDS AND MODERATE SEAS. A FEW SHOWERS AND TSTMS
MAY DEVELOP TUESDAY NIGHT INTO WEDNESDAY AS RIDGING ALOFT GIVES
WAY THE PASSAGE OF A MID LEVEL DISTURBANCE...BUT THE SURFACE
PATTERN WILL CONTINUE INTACT...THOUGH AN ADDITIONAL FOOT OF SWELL
MAY BE ADDED TO WAVE LOCAL HEIGHTS BY THURSDAY AS THE GRADIENT
PERSISTS OFFSHORE...CREATING A LONG EASTERLY FETCH.

&&

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

$$

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