Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 051129
AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
629 AM CDT TUE MAY 5 2015

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

&&

.AVIATION...MVFR CIGS DID NOT MATERIALIZE AT BRO AND HRL WITH
THOSE CIGS AFFECTING MFE ATTM. GUSTY WINDS TO BEGIN AROUND 14Z AT
WHICH TIME THOSE CIGS SHOULD BEGIN TO SCATTER TO VFR BY LATE
MORNING. GUSTS TO 30 KNOTS APPEAR POSSIBLE ESPECIALLY AT MFE WHERE
STRONGER LOW LEVEL WINDS RESIDE. WINDS WILL DECREASE AFTER SUNSET
BUT GUSTS WILL CONTINUE TILL AROUND MIDNIGHT. MVFR CIGS WILL BUILD
BACK IN AFTER SUNSET WHICH WILL CONTINUE THROUGH THE REST OF THE
TAF PERIOD.

&&

.PREV DISCUSSION... /ISSUED 416 AM CDT TUE MAY 5 2015/

SHORT TERM /NOW THROUGH WEDNESDAY/...UPPER TROF ACROSS THE FOUR
CORNERS REGION WILL OPEN UP AND WEAKEN AS IT HEADS NORTHEASTWARD
INTO COLORADO THEN BECOME ABSORBED IN THE DEEPENING LARGER SCALE
TROUGH ACROSS THE WESTERN CONUS. DIFFLUENCE REMAINS ACROSS THE
AREA BUT BETTER DYNAMICS ASSOCIATED WITH THE UPPER TROF WILL
REMAIN WELL REMOVED FROM THE AREA. 700MB FLOW STRENGTHENS AND
REINFORCES MID LEVEL CAPPING WITH DRY AIR ADVECTING FROM THE
MEXICAN PLATEAU AND OVER SPREADING THE AREA. LEFT SLIGHT CHANCE
POPS THIS MORNING FOR FAR WESTERN SECTIONS BUT BELIEVE CAP WILL
KEEP THE LID ON MOST IF NOT ALL PRECIPITATION TODAY. HRRR AND
NAM12 SUPPORT THIS IDEA. BREEZY CONDITIONS CONTINUE TODAY WITH
DEEPENING LOW PRESSURE ACROSS WEST TEXAS WITH GUSTS APPROACHING 30
MPH. THERE ARE INDICATIONS IN THE MODELS OF THUNDERSTORMS
DEVELOPING ON THE HIGHER TERRAIN THIS EVENING AND MOVE EASTWARD
TOWARDS OUR AREA BUT DRY AIR SHOULD WEAKEN THEM BEFORE MAKING
ACROSS THE RIVER. THEREFORE WILL KEEP FORECAST DRY TONIGHT. BREEZY
CONDITIONS CONTINUE WEDNESDAY WITH ANOTHER ROUND OF 700MB DRY AIR
ADVECTING FROM THE WEST. CONDITIONS WILL BE FAIRLY SIMILIAR TO THE
PAST SEVERAL DAYS. HIGHS IN THE 80S THE NEXT SEVERAL DAYS AND
PERHAPS REACHING 90 DEGREES IN THE FAR NORTHWESTERN SECTIONS OF
ZAPATA COUNTY. LOWS WILL BE IN THE 70S.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...AS LOW PRESSURE
TROUGHS DEEPEN ACROSS SW U.S. AND JUST OFF THE SE U.S. COAST MID
TO UPPER LEVEL RIDGE BUILDS OVER SOUTH TEXAS AND THE WESTERN
GULF. THIS SHOULD IN A MOSTLY DRY RAINFREE WED NIGHT THROUGH
SUNDAY PERIOD. NOT UNTIL THE WESTERN TROUGH BEGINS TO MOVE
NORTHEAST LATE NEXT WEEKEND INTO EARLY NEXT WEEK WILL THERE BE
SOME INCREASE IN THE CHANCE OF RAIN. MODELS REMAIN RATHER
PERSISTENT IN THIS PATTERN AND HAVE BEEN IN GOOD CONSISTENCY
MAKING FOR A BETTER THAN AVERAGE CONFIDENCE IN THE OUTGOING
FORECAST.

OVERALL, THE EARLY DOG DAYS OF SUMMER WILL BE SETTING UP AS THE
BUILDING UPPER RIDGE AND STRONG CAPPING INVERSION BETWEEN
850-700MB TO DOMINATE. THE BUILDING RIDGE PROMOTES A DIVERGENT Q
VECTOR FIELD OR A CONFLUENT FLOW ALOFT AND THE 850-700MB CAPPING
INVERSION STRENGTHENS WITH A THE PERSISTENT SOUTHWEST FLOW.
WITHOUT ANY LIFTING MECHANISM AND DISTURBANCES/VORT MAXES LIKELY
TO BE DIVERTED NORTHEAST OF THE AREA DO NOT SEE ANY SIGNIFICANT
CHANCE OF RAIN. WITH THAT SAID HAVE KEPT THE LOW CHANCE POPS
ACROSS THE NW ZONES JUST IN CASE A ROUGE THUNDERSTORM MOVES IN
FROM THE SIERRA MADRE.

WARM/HOT, HUMID AND BREEZY WILL BE THE WORD THROUGH AT LEAST
SUNDAY WITH WINDIEST DAYS NEXT WEEKEND AS THE UPPER TROUGH OVER
THE DESERT SW LIFTS INTO THE CENTRAL PLAINS STRENGTHENING  THE
PRESSURE GRADIENT. AS WE MOVE INTO NEXT WEEK MODELS SUGGEST AN
INCREASE IN RAIN CHANCES. THE WEAKENING OF THE RIDGE AND A
TRAILING COLD FRONT MOVING INTO CENTRAL TEXAS ALONG WITH POOLING
MOISTURE SOUTH OF THE BOUNDARY LOOKS TO THE INGREDIENTS NEEDED TO
GET A FEW STORMS IN OUR REGION. HAVE BROAD BRUSHED THE CWA WITH
LOW GRADE POPS NEXT MONDAY AND TUESDAY TO ACCOMMODATE THE MODEL
CONSENSUS.

MARINE...NOW THROUGH WEDNESDAY...MODERATE SOUTHEAST WINDS
AND MODERATE SEAS WILL CONTINUE AS HIGH PRES REMAINS DOMINANT
OVER THE SOUTHEAST U.S. AND THE NORTH GULF...COUNTERBALANCED BY
SOMEWHAT LOWER PRESSURE OVER THE SOUTHERN HIGH PLAINS. WINDS AND
SEAS MAY INCREASE SLIGHTLY AT TIMES...WITH SMALL CRAFT EXERCISE
CAUTION TO LOW END SMALL CRAFT ADVISORY CONDITIONS POSSIBLE.

WEDNESDAY NIGHT THROUGH SUNDAY...A MODERATE TO STRONG PRESSURE
GRADIENT TO PERSIST THIS PERIOD. BROAD HIGH PRESSURE OVER THE
GULF TO INTERACT WITH LOWER PRESSURE OVER NW TEXAS TO PRODUCE
MARGINAL SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY NIGHT THROUGH
FRIDAY. LOW PRESSURE STRENGTHEN OVER THE WEEKEND WITH A POSSIBLE
UPTICK IN WINDS AND SEAS.

&&

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

$$

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