Area Forecast Discussion
Issued by NWS Brownsville, TX

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000
FXUS64 KBRO 251547 AAB
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1047 AM CDT MON MAY 25 2015

.DISCUSSION...PLANNING TO MAKE SEVERAL MINOR BUT IMPORTANT
CHANGES FOR THE AFTERNOON AND EVENING BASED ON A BETTER SENSE OF
THE BIG PICTURE...AS WELL AS THIS BEING A FAIRLY BIG DAY AND EARLY
EVENING FOR OUTDOOR ACTIVITIES.

AWAITING THE ARRIVAL OF FIRST 12-18 HOURS OF GFS...BUT OTHER
MODELS INCLUDING THE NAM-12 AND ESPECIALLY THE HIGH RESOLUTION
RAPID REFRESH /HRRR/ WHICH PERFORMED MASTERFULLY SATURDAY
EVENING/OVERNIGHT WITH THE BIG PICTURE ELEMENTS THAT LED TO THE
QUASI-LINEAR CONVECTIVE SYSTEM...ARE INCREASINGLY PESSIMISTIC ON
NOTHING MORE THAN SPASH `N` DASH SHOWERS WITH A FEW RUMBLES
THROUGH THE AFTERNOON...ESPECIALLY BETWEEN 1 AND 4 PM.
THEREAFTER...STABILIZING WEST/SOUTHWEST FLOW ABOVE THE SURFACE
BECOMES MORE PRONOUNCED WHICH FAVORS A RAIN-FREE EVENING FOR THE
ENTIRE DEEP S. TEXAS/RIO GRANDE VALLEY AREA.

UNLIKE ON SATURDAY...WHEN LATE MORNING ACTION FIRED QUICKLY AND
WAS MOVING FROM THE SOUTH/SOUTHEAST TO THE NORTH/NORTHWEST IN A
MUCH MORE JUICED ATMOSPHERE...TODAY`S EARLY ACTIVITY ACROSS THE
RANCHLANDS WAS MOVING FROM THE SOUTHWEST TO THE NORTHEAST. WITH
DRIER AIR SET TO COME ACROSS THE SIERRA MADRE WEST/SOUTHWEST OF
ZAPATA COUNTY FIND IT DIFFICULT IF NOT IMPOSSIBLE TO REALIZE A
SOUTHWEST EXTENSION OF ANY QLCS BEYOND PORTIONS OF THE COASTAL
BEND. BOTTOM LINE? PLAN TO COLLAPSE MENTIONABLE RAIN AREA THIS
AFTERNOON TO THE LOWER VALLEY WITH HIGHER CHANCES IN THE KING
RANCH...SHARPLY LOWERING CHANCES TO THE WEST WHERE DRIER AIR ABOVE
800 MB SLIDES IN. THE LOWER TEXAS GULF WATERS TO THE BEACH
TYPICALLY DON`T RAIN IN THIS SITUATION SO HAVE TRIMMED BACK
CHANCES THERE AS WELL. PLAN TO REMOVE MENTIONABLE RAIN ENTIRELY
THIS EVENING WITH THE SOLE EXCEPTION OF THE KING RANCH AND GULF
WATERS THROUGH 10 PM.

AS FOR RIP (LONGSHORE) CURRENT THREAT AND STATEMENT...NO ISSUES
THERE. CURRENT WEB CAMS AND A RECENT GROUND OBSERVATION SUGGEST NO
CHANGES TO THE ACTIVE LONGSHORE (SOUTH TO NORTH) CURRENT ALONG
WITH CHOPPY 2 TO 3 FEET SURF WHICH FITS NICELY WITH ALERTING
HOLIDAY SWIMMERS...ESPECIALLY FROM JUST NORTH OF THE JETTIES
THROUGH THE PUBLIC ACCESS POINTS ON SOUTH PADRE ISLAND. WILL
REFRESH THE STATEMENT EARLY THIS AFTERNOON TO COVER THROUGH
EVENING...AND WILL LET DROP OVERNIGHT AS CROWDS WILL DROP OFF
SHARPLY BY TUESDAY.
52/BSG

&&

.MARINE UPDATE...WINDS/SEAS ARE SITTING JUST BELOW ADVISORY /20
KNOTS WITH 7 FEET/ CRITERIA THIS MORNING. LOW LEVEL WINDS STILL
RATHER STIFF THIS MORNING AND WITH LIKELIHOOD FOR MORE
BOATERS/FISHERS IN THE GULF DUE TO THE HOLIDAY PREFER TO KEEP
GUARD UP EVEN THOUGH AT THE MARGIN. WILL MAINTAIN CAUTION FOR THE
LAGUNA MADRE WITH WINDS IN SIMILAR RANGE...17 TO 21 KNOTS WITH
HIGHER GUSTS...THIS AFTERNOON.
52/BSG

&&

.PREV DISCUSSION... /ISSUED 632 AM CDT MON MAY 25 2015/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...LOW CLOUDS HAVE BEEN LIMITED TO INLAND LOCATIONS THIS
MORNING...WITH IFR CIGS AT KMFE. CLOUD COVER WILL VARY FOR THE
REST OF THE MORNING...WITH CIGS RISING TO AROUND 3000 BY NOON.
SOUTHEAST WINDS WILL INCREASE TO AROUND 20KTS THIS MORNING...WITH
HIGHER GUSTS THIS AFTERNOON. THUNDERSTORM COMPLEX FORMATION WILL
SWEEP THROUGH THE REGION THIS AFTERNOON...WITH VARIABLY GUSTY
WINDS AND LOWER VIS. WILL HOLD VCTS FOR THE MOMENT UNTIL
THUNDERSTORM TIMING IS BETTER KNOWN.

PREV DISCUSSION... /ISSUED 426 AM CDT MON MAY 25 2015/

SHORT TERM /TODAY THROUGH TUESDAY/...NEXT ROUND OF THUNDERSTORM
ACTIVITY EXPECTED TODAY AS THE NEXT SHORTWAVE LOBE SWEEPS AROUND
THE H5 TROUGH ACROSS THE WESTERN US. MODELS CONTINUE TO SHOW CAPE
VALUES ABOVE 3000 AREAWIDE BY NOON AND LASTING THROUGH THE
AFTERNOON. LATEST MODEL SOUNDINGS SHOWING AN INVERTED V SETUP...SO
ANY THUNDERSTORMS THAT DO DEVELOP WILL HAVE GUSTY WINDS. WILL
FOCUS FORECAST ON GUSTY WINDS AND HEAVY RAINFALL THREAT LATER THIS
AFTERNOON INTO THIS EVENING. AS THE SHORTWAVE SWEEPS TO THE NE
THIS EVENING...RAIN CHANCES WILL DECREASE. RIDGING STARTS TO TAKE
EFFECT TOMORROW MORNING...WITH A MORE STABLE ATMOSPHERE AND SLOWLY
DECREASING MOISTURE.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...MODELS ARE BEGINNING
TO SHOW SIGNS OF A MORE SUMMER LIKE PATTERN WITH THE BUILDING OF
THE SUBTROPICAL RIDGE OVER NORTHEAST MEXICO AND SOUTH TEXAS
WEDNESDAY AND THURSDAY. THE MID LAYER RIDGE PRODUCES SUFFICIENT
SUBSIDENCE AND LOWERS 700-500MB MOISTURE TO KEEP RAIN CHANCES NIL
TO 10 PERCENT. CAN NOT RULE OUT ANY DAYTIME SEABREEZE SHOWERS OR
A STRAY THUNDERSTORM THAT MAY DEVELOP OVER KENEDY AND BROOKS
COUNTY. THE RIDGE BEGINS TO BREAK DOWN AS THE MAIN HIGH CENTER
OVER THE SOUTHEAST U.S. COAST WEAKENS ITS HOLD AND SHIFTS
EASTWARD. THIS ALLOWS FOR OUR REGION TO BEGIN TO FEEL THE IMPACTS
OF THE UPSTREAM UPPER TROUGH. ALTHOUGH MOISTURE VALUES DO NOT
INCREASE OR DEEPEN THAT MUCH A MORE ESE-E FLOW ALLOWS FOR A
SLIGHTLY BETTER CHANCE OF A SEA BREEZE TO SET UP. BEST CHANCES
LOOK TO BE NEXT WEEKEND AS THE UPPER TROUGH PASSES OVER NORTH
TEXAS. WILL KEEP THE MENTION OF 20 PERCENT WHICH IS JUST BELOW
MODEL CONSENSUS. LITTLE SPREAD AMONG THE TEMPERATURES GUIDANCE
AND CONSISTENCY REMAINS GOOD WITH THE LOWER CHANCES OF RAIN.
TEMPERATURES WILL BE SUMMER LIKE WITH UPPER 80S ALONG THE COAST TO
MID 90S INLAND WEST.

MARINE /TODAY THROUGH TUESDAY/...GULF WATERS HAVE STABILIZED AT
AROUND 5 FEET AS WINDS REMAIN AROUND 15 KNOTS. BREEZY SOUTHEAST
WINDS CONTINUE TODAY DUE TO GRADIENT BETWEEN LOW IN THE CENTRAL
PLAINS AND RIDGE ACROSS THE EASTERN US. THIS WILL CHURN SEAS BACK UP
TO 5 TO 6 FEET. CONDITIONS WILL BE FURTHER AFFECTED BY ANY
THUNDERSTORM ACTIVITY THAT MOVES INTO THE COASTAL WATERS LATE THIS
AFTERNOON. AS THE LOW MOVES OFF TO THE NE TONIGHT...GRADIENT
RELAXES...WITH WINDS LOWERING INTO THE LOWER TEENS. SEAS WILL SLOWLY
RELAX AGAIN BACK TO AROUND 4 FEET.

TUESDAY NIGHT THROUGH FRIDAY...MID LEVEL HIGH PRESSURE BUILDS
ALONG THE TEXAS COAST AND WESTERN GULF OF MEXICO. SOUTHEAST FLOW
BECOMES MODERATE MAINTAINING A MODERATE SEA. WINDS TO INCREASE
TOWARDS THE WEEKEND WITH MARGINAL SMALL CRAFT ADVISORY CONDITIONS
FRIDAY THROUGH THE WEEKEND AS THE RIDGE MOVES EAST AND ANOTHER
UPPER LOW PRESSURE TROUGH MOVES ACROSS NORTHERN TEXAS.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  88  79  89  80 /  40  10  10  10
BROWNSVILLE          89  78  90  79 /  40  10  10  10
HARLINGEN            90  77  92  78 /  40  10  10  10
MCALLEN              91  78  93  79 /  40  10  10  10
RIO GRANDE CITY      93  76  93  77 /  30  10  10  10
SOUTH PADRE ISLAND   87  79  87  80 /  50  10  10  10

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR TXZ251-256-257.

GM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ150-155-
     170-175.

&&

$$

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