Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 100544 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1244 AM CDT THU JUL 10 2014

.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. IN
ADDITION...INCREASED POPS BY ABOUT 10 PERCENT ACROSS THE BOARD
NEXT 24 HOURS BASED ON CURRENT TRENDS AND IN VIEW OF CONVECTIVE
FLARE UP TO THE SOUTH ALONG THE NORTHEAST MEXICAN COASTLINE. THIS
ACTIVITY IS EXPECTED TO MOVE NORTH INTO THE AREA. MODEL GUIDANCE
IS TRENDING UP IN THIS RESPECT AND FURTHER INCREASES MAY BE
WARRANTED WITH THE PENDING MORNING FORECAST.

&&

.AVIATION...DEFINITE INCREASE IN CONVECTIVE THREAT FOR AVIATION
INTERESTS TODAY. LACK OF STRONG MARINE LAYER/INVERSION MAY
PRECLUDE EXCESSIVE LOW CLOUDS FOR NOW...AND CEILINGS MAY REMAIN
VFR EXCEPT IN ANY HEAVIER CONVECTION. TAFS INDICATE PROB30 GROUPS
SINCE MAIN FORECAST ONLY SHOWING LOWER END CHANCE POPS FOR NOW...
BUT HIGHER POPS STILL POSSIBLE AS MODEL GUIDANCE HAS BEEN MORE
BULLISH...AND MAY NEED TO MODIFY TAFS TO INCLUDE TEMPO GROUPS
WITH LATER UPDATES.

&&

.PREV DISCUSSION... /ISSUED 305 PM CDT WED JUL 9 2014/

SHORT TERM....SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...SATELLITE
AND RADAR IMAGES CONTINUE TO INDICATE SHOWERS AND THUNDERSTORMS
CONTINUE TO DEVELOP ACROSS NORTHEAST PORTIONS OF THE CWA THIS
AFTERNOON. LOW TO MID LEVEL MOISTURE WILL REMAIN HIGH ACROSS
NORTHEAST MEXICO AND THE LOWER RIO GRANDE VALLEY TONIGHT INTO
THURSDAY AS A 500MB LOW ACROSS NORTHEAST MEXICO PROVIDES A CHANCE
OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA TONIGHT INTO
THURSDAY. BEST RAIN CHANCES APPEAR LATE TONIGHT INTO THURSDAY
MORNING. WILL GO AHEAD AND RAISE POPS SLIGHTLY HIGHER TONIGHT AND
THURSDAY AS A RESULT. CLOUD COVER WILL LIMIT DIURNAL HEATING TO
SOME DEGREE THURSDAY SO HIGHS THURS AFTERNOON WILL BE SLIGHTLY
LOWER THAN TODAY. WILL GO WITH A BLEND OF THE RAW AND MOS
CONSENSUS MODEL GUIDANCE FOR TEMPERATURES TONIGHT THROUGH THURS
NIGHT.

LONG TERM /FRIDAY THROUGH WEDNESDAY/...THE UPPER LOW PRESSURE
THROUGH THAT HAS BEEN ANCHORED OVER TEXAS AND THE NORTHWESTERN
GULF OF MEXICO FOR THE LAST SEVERAL WEEKS WILL BEGIN TO WEAKEN AND
CONTINUE TO DRIFT WEST UNDER A STRENGTHENING UPPER RIDGE. THE HIGH
PRESSURE RIDGE WILL BECOME THE MORE DOMINATE FEATURE BRING WITH
WARMER TEMPERATURES AND CUTTING OFF THE CHANCE RAIN FOR THE
UPCOMING WEEKEND AND MUCH OF NEXT WEEK.

FRIDAY...THE UPPER TROUGH AXIS TO EXTEND ALONG AND WEST OF OUR
WESTERN COUNTIES EARLY FRIDAY CONTINUING TO MOVE WESTWARD.
AVAILABLE MOISTURE BETWEEN 925-700MB WILL BE LIMITED WITH STILL
PLENTY OF MOISTURE ABOVE THE 700MB LAYER AND AT THE SURFACE. BEST
MOISTURE TO FAVOR THE WESTERN COUNTIES CLOSER TO THE TROUGH AXIS.
MODEST SOUTHERLY FLOW CONTINUES AND BELIEVE MODELS ARE A BIT QUICK
AND TO AGGRESSIVE WITH THE DEPLETION OF THE MOISTURE. CURRENT
FORECAST DID NOT EXCEED GUIDANCE VALUES AT THIS TIME WITH MEDIUM
CONFIDENCE THAT THE TROUGH WILL CONTINUE TO MOVE WESTWARD
WEAKENING THE SUPPORT NEEDED TO LIFT THE MOISTURE.

THE REST OF THE WEEK LOOKS DRY WITH GFS SHOWING SIGNIFICANT DRYING
THROUGH THE ATMOSPHERIC LAYER. ONLY THE TYPICAL LOW LEVEL MOISTURE
TO LINGER AOB 850MB PROVIDING THE DAYTIME CU FIELD. WITH MORE HIGH
PRESSURE COMES MORE SUBSIDENCE WHICH SHOULD RESULT IN WARMER
TEMPERATURES. 850MB TEMPERATURES DO CLIMB 2 TO 3C DEGREES BY
TUESDAY WHICH IS QUITE MODEST FOR MID JULY. GUIDANCE VALUES TREND
UPWARD AS DOES THE NWS FORECAST NUMBERS.

MARINE/TONIGHT THROUGH THURSDAY NIGHT...SEAS WERE NEAR 2 FEET
WITH SOUTH WINDS NEAR 12 KNOTS AT BUOY020 THIS AFTERNOON. LIGHT
TO MODERATE SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS
TONIGHT THROUGH THURSDAY WITH THE PRESSURE GRADIENT REMAINING WEAK
ACROSS THE LOWER TEXAS COAST AS SURFACE HIGH PRESSURE PREVAILS
ACROSS THE GULF OF MEXICO.

/FRIDAY THROUGH MONDAY/...BROAD SURFACE HIGH PRESSURE TO PERSIST
OVER THE NORTHERN GULF OF MEXICO THROUGH THE PERIOD. LIGHT TO
MODERATE ONSHORE FLOW TO CONTINUE. BRIEF PERIODS OF STRONGER WINDS
APPROACHING EXERCISE CAUTION LEVELS FRIDAY AFTERNOON AND EVENING
WITH A LOW PRESSURE TROUGH OVER WESTERN TEXAS AND THEN AGAIN NEXT
MONDAY AND TUESDAY AS A THERMAL LOW OVER NORTHEAST MEXICO AND
SOUTHWEST TEXAS INITIATES A STRONGER PRESSURE GRADIENT BETWEEN
STRONG HEATING INLAND AND THE SOMEWHAT COOLER GULF WATERS. SEAS TO
RESPOND LATE IN THE PERIOD WITH AN INCREASE OF A FOOT OR TWO.

&&

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

$$

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