Area Forecast Discussion
Issued by NWS Brownsville, TX

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000
FXUS64 KBRO 310527 AAB
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1227 AM CDT THU JUL 31 2014

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

&&

.AVIATION...UPDATED TO A MORE PESSIMISTIC NEXT SEVERAL HOURS WITH
CLOUD COVER INCREASING OVER HIDALGO COUNTY AND A SOLID INVERSION
ON THE EVENING SOUNDING SUGGESTING A BETTER CHANCE OF MORE STEADY
CIGS AROUND 1800 TO 2200 FT. WILL LIKELY STILL BE SOME PERIODS OF
SKC/SCT MIXED IN WITH THE BROKEN BUT GIVEN MOISTURE/THERMAL
PROFILES ODDS SUPPORT PREVAILING MVFR THROUGH THE OVERNIGHT INTO
THE FIRST FEW HOURS OF FRIDAY MORNING. WINDS WILL STAY ON THE
GUSTY SIDE WEST OF HIGHWAY 281 WITH A STRONG LOW LEVEL JET
PERSISTING THROUGH AROUND 14Z.

FRIDAY SHOULD OPEN UP TO MVFR BY 14-15Z WITH GUSTY SOUTHEAST WINDS
RETURNING AGAIN. PREVAILING GUSTS AROUND 25 TO 30 KNOTS WITH
MOSTLY CLEAR SKIES. SMALL POSSIBILITY FOR CONVECTION TO APPROACH
HBV/BKS BUT UNLIKELY TO APPROACH VALLEY/TAF SITES BEFORE 06Z
FRIDAY. /68-JGG/

&&

.PREV DISCUSSION... /ISSUED 807 PM CDT WED JUL 30 2014/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...MID LEVEL AND SURFACE RIDGING WILL MAINTAIN CONTROL
OF THE AVIATION CONDITIONS OVER DEEP SOUTH TX THROUGHOUT THE NEXT
24 HOURS. SOME PATCHY SCT SC CLDS ARE POSSIBLE THROUGHOUT THE
OVERNIGHT HOURS. THE LAST VSBL IMAGE JUST BEFORE SUNSET SHOWED A
BIT OF A SCT-BKN DECK FORMING OVER EASTERN CAMERON COUNTY. BELIEVE
THAT THIS DECK WILL BE FAIRLY SHORT AND HAVE INCLUDED A TEMPO
REMARK FOR THE BRO TAF THROUGH 03Z THIS EVENING. DAYTIME HEATING
AND INCREASE LOW LEVEL MIXING TOMORROW WILL LIKELY MAINTAIN VFR
CONDITIONS THROUGH 00Z TOMORROW EVENING. OTHER THAN THE BKN DECK
AFFECTING THE BRO AREA OVER THE NEXT COUPLE OF HOURS...EXPECT VFR
CONDITIONS TO DOMINATE.

PREV DISCUSSION... /ISSUED 332 PM CDT WED JUL 30 2014/

SHORT TERM /NOW THROUGH THURSDAY NIGHT/...
PRIMARY WEATHER IMPACT...HIGH HEAT INDEX VALUES

THE LATEST BATTERY OF SUBJECTIVE ANALYSES CONTINUE TO SHOW (SOMEWHAT
WEAKENED) RIDGING ALOFT ACROSS OUR AREA...WITH NARY A CLOUD IN THE
SKY IN MOST PLACES.  THERE WERE A FEW EXCEPTIONS CLOSER TO THE
COAST...WHERE BOUNDARY LAYER MOISTURE REMAINED SUFFICIENT TO ALLOW A
FEW CUMULI TO DEVELOP.  EVEN THOSE SHOULD DISSIPATE BEFORE SUNSET.

FARTHER NORTH...A WARM FRONT EXTENDED GENERALLY NEAR A
LUBBOCK-DFW-TYLER-LUFKIN LINE EARLY THIS AFTERNOON.  THIS BOUNDARY
IS EXPECTED TO START MOVING SOUTHWARD ACROSS THE LONE STAR STATE
OVER THE NEXT 24 HOURS OR SO...DRIVEN BY SHORTWAVE TROUGHS TOPPING
THE RIDGE AND MIGRATING SOUTHEASTWARD ACROSS THE CENTRAL PLAINS.
THE RESULT WILL LIKELY BE AN OVERALL WEAKENING OF THE UPPER RIDGE IN
OUR REGION AS WE HEAD TOWARD THE END OF THE WEEK.  FORECAST
SOUNDINGS SUGGEST THAT WE PROBABLY WON`T SEE A SIGNIFICANT CHANGE IN
BOUNDARY LAYER MOISTURE UNTIL AFTER THE LONG TERM PORTION OF THE
FORECAST.

SO IN GENERAL...SENSIBLE WEATHER CONDITIONS SHOULD LARGELY REMAIN
UNCHANGED THROUGH THURSDAY NIGHT.  EXPECT A CONTINUATION OF
GENERALLY DRY AND HOT CONDITIONS THROUGH THURSDAY NIGHT.  WIND
SPEEDS WILL LIKELY INCREASE JUST A BIT BEGINNING TONIGHT...AS A
DEVELOPING SURFACE LOW NEAR THE MEXICAN STATES OF CHIHUAHUA AND
COAHUILA AIDS IN STRENGTHENING THE PRESSURE GRADIENT.  THE UPSIDE TO
THE INCREASED MIXING IS THAT AFTERNOON HEAT INDICES...ALTHOUGH ABOVE
THE CENTURY MARK (SOMEWHERE AROUND 105)...SHOULD REMAIN BELOW
ADVISORY CRITERIA.  SIMILAR THE PAST DAY OR TWO...WIND SPEEDS NEAR
THE IMMEDIATE COAST WILL LIKELY BE SLIGHTLY LOWER...THANKS TO A
MARINE LAYER MEDDLING IN THE FORECAST.  /BUTTS/

LONG TERM /FRIDAY THROUGH WEDNESDAY/...FOR A CHANGE THE
LATHER...RINSE AND REPEAT SEQUENCE AS OF LATE IS THE NOT STATUS QUO.
THE UPPER TROUGH BEGINS TO ELONGATE THROUGH WEEKEND AND
WEAKEN...WHILE THE UPPER RIDGE REMAINS ANCHORED OVER THE WESTERN
STATES. THE INFLUENCE OF THIS UPPER RIDGE LESSENS FOR THE WEEKEND
AS THE TROUGH SHUNTS IT SLIGHTLY AWAY TO THE WEST.

THE WEATHER MAKER FOR THE PERIOD REMAINS THE FRONTAL BOUNDARY THIS
WEEKEND. THE WEAK FRONT WILL CONTINUE ITS SLOW MARCH SOUTHWARD
ACROSS SOUTH CENTRAL TEXAS ON FRIDAY. THE BIGGEST QUESTION IS
HOW FAR SOUTH DOES THE FRONT MAKE IT BEFORE IT STALLS/WASHES OUT.
CONCUR WITH MODEL GUIDANCE THAT KEEPS THE FRONT OVER OR JUST NORTH
OF THE RANCHLANDS. MOISTURE POOLS ALONG THE FRONT WITH PWATS
SOARING TO AROUND 2.2 INCHES BY SUNDAY AFTERNOON...NEARLY 2
STANDARD DEVIATIONS ABOVE NORMAL. THE COMBINATION OF INSTABILITY
AND MOISTURE WILL LEAD TO THE DEVELOPMENT OF CONVECTIVE ACTIVITY
OVER THE WEEKEND ALONG THE BOUNDARY AS WELL AS IN CONJUNCTION TO
THE SEA BREEZE.

TEMPERATURES WILL REMAIN QUITE TOASTY ON FRIDAY BUT WITH THE
INCREASED CLOUD COVER AND PRECIP THIS WEEKEND...TEMPERATURES...WHILE
STILL HOT...BECOME MORE MODERATED.

MARINE...
TONIGHT THROUGH THURSDAY NIGHT... IT STILL LOOKS LIKE ONSHORE
WINDS MAY INCREASE JUST A SKOSH TONIGHT...AS A DEVELOPING LOW
PRESSURE AREA IN NORTHERN MEXICO STRENGTHENS THE PRESSURE
GRADIENT. WINDS MAY FLIRT WITH SMALL CRAFT EXERCISE CAUTION
CRITERIA (MAINLY OVER THE LAGUNA) THROUGH THURSDAY...WITH FREQUENT
GUSTS UP TO 20 KNOTS POSSIBLE. OTHERWISE...YOU CAN LARGELY EXPECT
MORE OF THE SAME OVER THE MARINE AREA THROUGH THE SHORT TERM.
SOUTHEAST TO SOUTH WINDS UP TO 15 KNOTS (OCCASIONALLY LOWER) ARE
EXPECTED...WITH COMBINED WAVE HEIGHTS EXPECTED TO AVERAGE 2 FEET
WITH A 4-5 SECOND PERIOD. /BUTTS/

FRIDAY THROUGH MONDAY...LIGHT TO MODERATE EAST SOUTHEAST WINDS AND LOW
SEAS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD AS A WEAK FRONTAL
BOUNDARY PUSHES SOUTH ACROSS SOUTH TEXAS. SHOWER AND THUNDERSTORM
CHANCES INCREASE OVER THE WEEKEND. WINDS AND SEAS WILL TEMPORARILY
INCREASE IN AND NEAR ANY SHOWER AND THUNDERSTORM ACTIVITY.

&&

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

$$

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