Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 282004
AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
304 PM CDT MON JUL 28 2014

SHORT TERM /NOW THROUGH TUESDAY NIGHT/...
THE WEATHER WORD FOR THE SHORT TERM WILL LARGELY BE RIDGING.

DESPITE A SEABREEZE TRYING ITS BEST TO MOVE WESTWARD ACROSS THE
FORECAST AREA AT MID-AFTERNOON...THE ONLY CONVECTIVE DEVELOPMENT HAS
BEEN IN THE FORM OF SOME SCATTERED...FLAT CUMULI.  THIS WAS LARGELY
THANKS TO THE PRESENCE OF UPPER-LEVEL RIDGING...WHICH WAS CENTERED
NEAR NORTHEAST NEW MEXICO THIS AFTERNOON.  ANY CLOUD COVER SHOULD
LARGELY DISSIPATE AFTER SUNSET...ALLOWING MOSTLY CLEAR SKIES TO
GENERALLY BE SEEN.

SIMILAR TO THE PAST COUPLE OF MORNINGS...SOME PATCHY STRATUS IS
EXPECTED TO DEVELOP NEAR/JUST SOUTH OF THE RIO GRANDE AND MOVE
NORTHWARD DURING THE PRE-DAWN HOURS.  THE STRATUS SHOULD DISSIPATE
AROUND MID-MORNING...AS MECHANICAL MIXING INCREASES ACROSS THE
FORECAST AREA.  TUESDAY WILL LARGELY BE SIMILAR TO TODAY...AS THE
UPPER RIDGE ALLOWS ONLY SOME FLAT CUMULUS CLOUDS TO DEVELOP DURING
THE AFTERNOON HOURS.

FORECAST HIGH TEMPERATURES SHOULD REMAIN JUST ABOUT ON PAR WITH
TODAY...WITH MOST PLACES REACHING WELL INTO THE 90S.  COMBINED WITH
THE HUMIDITY...AFTERNOON HEAT INDICES WILL LIKELY REACH INTO THE 105
TO 109 DEGREE RANGE ONCE AGAIN.  ALTHOUGH HIGH...THESE VALUES STILL
DO NOT MEET LOCAL HEAT ADVISORY CRITERIA.  /BUTTS/

.LONG TERM/WEDNESDAY THROUGH MONDAY/...

ON WEDNESDAY ANOTHER ANOMALOUS LATE JULY TROUGH WILL BE DIGGING INTO
THE EASTERN CONUS AND THE JET MAX ON THE WESTERN SIDE OF THAT TROUGH
WILL BE DEEPENING LOW LEVEL TROUGHING AND GENERATING A SURFACE CYCLONE
OVER NORTH CENTRAL TEXAS. WEAK BUT PRESENT RIDING OVER THE GULF WILL
INTERACT WITH THIS TO PRODUCE A NOTICEABLY BREEZY DAY ON WEDNESDAY.
CONTINUED THE FORECAST OF 20 TO 25 MPH WINDS WITH GUSTS 30 TO 35 MPH
IN THE NEW FORECAST WHICH IS A LITTLE HIGHER THAN GUIDANCE CONSENSUS
BUT GIVEN THE STRENGTH OF THE TROUGH AND THE RUN TO RUN TREND
BELIEVE EXISTING FORECAST HAS IT RIGHT. 850MB RELATIVE HUMIDITY
REMAINS LOW WITH NO RECHARGE FROM MULTIPLE DAYS OF STRONG SUBSIDENCE
AND RAIN CHANCES REMAIN NEAR ZERO. HOT TEMPERATURES...CLOSE TO THE
LAST SEVERAL DAYS ARE FORECAST.

THURSDAY THE TROUGH CONTINUES ITS EASTWARD TREK INTO THE OHIO VALLEY
WHILE LEE TROUGHING AND THE REMNANT LOW FROM WEDNESDAY MOVE VERY
CLOSE TO THE VALLEY WITH THE CENTER...WHEN COMBINED WITH THERMAL
TROUGHING...LIKELY OVER NUEVO LEON. THIS WILL KEEP SOUTHEASTERLY
WINDS FAIRLY STRONG NEAR THE COAST BUT LOWERING PRESSURE OVER THE
WESTERN ZONES MAY KNOCK WIND SPEEDS DOWN A BIT. SOUTHWESTERLIES AT
850/700MB WILL CONTINUE TO KEEP THAT LAYER WARM AND DRY AND KEEP
ORGANIZED PRECIP AT BAY. LITTLE CHANGE IN MIN OR MAX T ANTICIPATED
FROM THE PREVIOUS DAYS...ALTHOUGH IF THE LOW WERE TO STAY A LITTLE
FURTHER NORTH THAN CURRENTLY INDICATED SURFACE SOUTHWESTERLIES MAY
INDUCE A SPIKE IN TEMPS...MAINLY WEST OF HIGHWAY 281.

FRIDAY REINFORCING NORTHWEST FLOW GENERATES AND PROPAGATES A FEW
WEAK SHORTWAVE PERTURBATIONS THAT APPEAR TO INITIATE THUNDERSTORMS
TO THE NORTH OF THE AREA IN THE AFTERNOON BEFORE MOVING
SOUTHEASTWARD INTO THE AREA FRIDAY NIGHT. CONTINUED A SLIGHT CHANCE
OF SHOWERS AND STORMS BEFORE MIDNIGHT NORTH OF THE VALLEY AND
BROUGHT A SLIGHT CHANCE OF SHOWERS AND STORMS EARLY SATURDAY MORNING
INTO PORTIONS OF THE VALLEY. MAY NOT QUITE BE ENOUGH
INSTABILITY/CONVERGENCE TO CONTINUE ACTIVITY FOR THAT LONG HOWEVER.
IT IS NOTED THOUGH THAT BY LATE THURSDAY INTO FRIDAY THE
CAPPING/DRYING SOUTHWESTERLIES WILL HAVE DIMINISHED AS THE LOW PARKS
NEARBY AND OUR THERMODYNAMIC ENVIRONMENT SHOULD BE IMPROVED BY MID
LEVEL LAPSE RATES STEEPENING INVOF THE SHORTWAVES AND RICHER/DEEPER
MOISTURE PUSHING IN ON WEAK LOW LEVEL SOUTHEASTERLIES SO THE RAIN
CHANCES OVERALL WILL BE ON THE RISE.

SATURDAY THE REMNANT BOUNDARY STALLS NEAR THE AREA INVOF THE
NORTHWEST FLOW. DO NOT SEE ANY REAL INDICATIONS OF SUPPORT ABOVE THE
SURFACE OR COLD ADVECTION AND THE AIRMASS CHANGE GETS PRETTY BROAD
BY THIS POINT SO ACADEMICALLY ITS NOT QUITE A COLD FRONT AND OUR
TEMPERATURES DEFINITELY WILL NOT BE CHANGING MUCH BUT THE BOUNDARY
STICKS OVER THE AREA AMID RICH AND DEEP LOW LEVEL MOISTURE AND
NORTHWEST FLOW ALOFT WITH IMPROVING AGREEMENT IN THE 12Z SUITE
AMONGST GFS/ENSEMBLE/ECMWF MEMBERS SO BUMPED AFTERNOON RAIN CHANCES
INTO THE 30 PCT RANGE WITH THE ONLY LIMITING FACTOR BEING PALTRY
REMNANT LAPSE RATES THAT MAY NOT QUITE YIELD ENOUGH INSTABILITY TO
FULLY TAKE ADVANTAGE OF THE SITUATION. IF IT PANS OUT THOUGH WITH
PRECIPITABLE WATER FORECASTS AROUND 2.00 INCHES AND SLOW STORM
MOTION COULD BE A PRETTY EFFICIENT RAINFALL PRODUCER. CLOUD/MOISTURE
WILL KEEP TEMPS A FEW DEGREES BELOW PREVIOUS DAYS STANDARDS.

THE SAME EXISTS FOR SUNDAY WITH THE BOUNDARY A LITTLE MORE DIFFUSE.
GFS/ECMWF SHOW BETTER DIFFERENTIAL POSITIVE VORTICITY ADVECTION IN
THE 300/500MB LAYER THOUGH AS THE CENTER OF THE NOW SEMI-CLOSED
UPPER LOW BEGINS TO RETROGRADE SOUTWESTWARD. KEPT 30 PCT POPS DURING
THE AFTERNOON WITH AT LEAST A SLIGHT CHANCE IN MOST AREAS DURING THE
OVERNIGHT SATURDAY. SOME INDICATIONS THAT AN EASTERLY WAVE WILL PUSH
IN SOUTH OF THE BOUNDARY AND FURTHER JUICE UP THE ATMOSPHERE. IT
SHOULD BE NOTED HOWEVER THAT NORTHWESTERLY FLOW PATTERNS
TRADITIONALLY PRODUCE SOME OF OUR MORE ROBUST SUMMER THUNDERSTORM
EVENTS AND THE ADDITION OF THE SURFACE BOUNDARY AND POSSIBLY THE
EASTERLY WAVE MAKE FOR AN INTERESTING /POTENTIAL/ COMBINATION. WILL
BE MONITORING CLOSELY.

MONDAY THE WAVE CONTINUES TO PERSIST BUT THE EVIDENCE OF THE
RESIDUAL BOUNDARY BEGINS TO DISAPPEAR. WITH DEEP AND RICH AVAILABLE
MOISTURE HOWEVER KEPT 20/30 POPS IN THE FORECAST FOR THE AFTERNOON
HOURS AND KEPT TEMPERATURES MODERATED. /68-JGG/


&&

.MARINE...

TONIGHT THROUGH TUESDAY NIGHT...
RATHER TRANQUIL MARINE CONDITIONS ARE EXPECTED DURING THE SHORT
TERM...AS RIDGING DOMINATES THE MARINE AREA.  IN GENERAL...A
CONTINUATION OF THE STATUS QUO IS LARGELY EXPECTED...WITH COMBINED
SEAS AVERAGING 2 TO 3 FEET...AND WIND SPEEDS HOVERING AROUND 10
KNOTS...WITH THE SLIGHTLY HIGHER SPEEDS CLOSE TO THE IMMEDIATE COAST
AND IN THE LAGUNA.  /BUTTS/

WEDNESDAY THROUGH FRIDAY...
BREEZY CONDITIONS ARE EXPECTED BOTH WEDNESDAY AND THURSDAY WITH
MARGINAL ADVISORY CONDITIONS POSSIBLE ON THE LAGUNA MADRE BOTH
WEDNESDAY AND THURSDAY AND EXERCISE CAUTION CONDITIONS POSSIBLE ON
THE GULF BOTH WEDNESDAY AND THURSDAY IN THE EVENING. WINDS SHOULD
BECOME LIGHTER ON FRIDAY. GENERALLY MODERATE SEAS ARE EXPECTED
WEDNESDAY AND THURSDAY WITH LOW SEAS ON FRIDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  79  94  79  96 /   0   0   0  10
BROWNSVILLE          78  95  79  97 /   0   0   0  10
HARLINGEN            77  97  78  99 /   0   0   0  10
MCALLEN              77 100  77 101 /   0   0   0  10
RIO GRANDE CITY      77 103  78 103 /   0   0   0  10
SOUTH PADRE ISLAND   80  89  81  89 /   0   0  10  10

&&

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

$$

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

SHORT TERM...52-BUTTS
LONG TERM...68-GIBBS
UPPER AIR/GRAPHICAST...66-TOMASELLI





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