Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 022314 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
614 PM CDT SAT MAY 2 2015

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

.AVIATION...MINOR ADJUSTMENTS TO THE PREVIOUS ISSUANCE OF TAFS.
ENOUGH WIND SHOULD REMAIN OVERNIGHT TO ALLOW ONLY FOR THE LIGHTEST
OF FOG. CEILINGS WERE REDUCED 1K FEET AND INITIATED ABOUT TWO
HOURS EARLIER THAN PREVIOUSLY INDICATED. AND SURFACE WINDS ON
SUNDAY SHOULD BE A LITTLE MORE BREEZY THAN ORIGINALLY FORECAST.
OVERALL...MVFR TONIGHT SHOULD GIVE WAY TO VFR AFTER SUNRISE ON
SUNDAY.
&&

.PREV DISCUSSION... /ISSUED 251 PM CDT SAT MAY 2 2015/

SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/...

SURFACE HIGH PRESSURE OVER THE NORTHERN GULF WILL CONTINUE TO SHIFT
EAST THROUGH THE PERIOD. MID LEVEL RIDGING CONTINUES TO SLIDE EAST
AS WELL WHILE A SHORT WAVE APPROACHES SOUTHERN CALIFORNIA TONIGHT
INTO SUNDAY AND MOVES ONSHORE SUNDAY NIGHT.  AS THE SHORTWAVE
APPROACHES...LEE TROUGHING STRENGTHENS ACROSS THE PLAINS...WEST
TEXAS AND ALONG THE SIERRA MADRE TONIGHT INTO SUNDAY. LLJ DEVELOPS
ACROSS THE AREA TONIGHT AND LINGERS THROUGH THE PERIOD WITH 20 TO 25
KTS AT 925MB.

TONIGHT...SURFACE WINDS WILL BE ON THE LIGHT SIDE WITH A FEW MORE
CLOUDS AND POSSIBLY SHALLOW GROUND FOG DEVELOPING IF WINDS DROP LOW
ENOUGH...PRIMARILY ALONG AND EAST OF THE HWY 281 CORRIDOR. WITH THE
RETURNED MOISTURE...INCREASING DEWPOINTS AND SOUTHEASTERLY FLOW
REESTABLISHED...LOW TEMPERATURES IN THE 50S ARE GONE AND REPLACED BY
TEMPERATURES IN THE MID 60S OR HIGHER ACROSS MUCH OF THE AREA.

SUNDAY AND SUNDAY NIGHT...THE COMBINATION OF THE STRENGTHENING
PRESSURE GRADIENT DUE TO THE LEE TROUGHING AND THE MIXING DOWN OF
WINDS WILL RESULT IN BREEZY CONDITIONS DEVELOPING ACROSS THE CWA. A
FEW MORE CLOUDS CAN BE EXPECTED AS WELL...AS LOW LEVEL MOISTURE
CONTINUES TO INCREASE.  MODELS CONTINUE TO INDICATE PRECIP
DEVELOPING ACROSS THE EASTERN CWA DURING THE AFTERNOON HOURS AS A
WEAK SHORT WAVE PASSES NORTH OF THE REGION. DEEP LAYER MOISTURE IS
LIMITED WITH 1000 TO 500MB LAYER RH REMAINING BELOW 70 PERCENT...BUT
LOWER LEVELS ARE A LITTLE MORE MOIST WITH THE 1000 TO 700MB LAYER RH
AT 70 TO 75 PERCENT. SO HAVE MAINTAINED A SLIGHT CHANCE FOR SHOWERS
BUT CONFIDENCE IS LOW WITH THE RAIN CHANCES. TEMPERATURES CONTINUE
THEIR UPWARDS TREND WITH HIGHS IN THE MID TO UPPER 80S AND LOWS IN
THE UPPER 60S TO LOWER 70S.

LONG TERM.../MONDAY THROUGH SATURDAY NIGHT/...EARLY IN THE LONG TERM
PERIOD AN OPEN WAVE MOVES INLAND FROM THE SOUTHERN CA COAST WITH SOME
SHORTWAVES WITHIN THE UPPER LEVEL FLOW MOVING INLAND ACROSS THE DESERT
SOUTHWEST. THE RIPPLES ASIDE TO THE FAVORABLE SOUTHEAST INFLUX OF DEEP
MOISTURE FROM THE GULF WILL ENHANCE ISOLATED SHOWERS EAST OF THE SIERRA
MADRE AND THE FOUR CORNERS REGION. IN OUR REGION...THE CLOUD COVER WILL
BE ON THE INCREASE AS THE 1000 TO 500RH SHOW VALUES OF 50 TO 60 PERCENT
AND HIGHER EVEN FURTHER WEST WHERE THE HIGHER POTENTIAL FOR CONVECTION
WILL BE. THIS DEEPER MOISTURE WILL ENHANCE THE CONVECTION MONDAY LATE
AFTERNOON AND EVENING AND A FEW OF THOSE SHOWERS COULD SNEAK INTO THE
WESTERN PORTION NEAR ZAPATA...STARR AND JIM HOGG COUNTY. THE CLOUD DECK
WILL ALLOW FOR TEMPS TO REMAIN IN THE MID TO UPPER 80S ACROSS DEEP SOUTH
TEXAS MONDAY. INTO TUESDAY...THE UPPER LOW CONTINUES ITS TRAJECTORY NE
AND E ACROSS THE FOUR CORNERS REGION PROVIDING A MORE DIFFLUENT FLOW
ALOFT ACROSS SOUTH TEXAS. THE BETTER DYNAMIC STILL REMAINS FURTHER
NORTH WITH DEEPER MOISTURE AND BETTER UPPER LEVEL DIVERNGENCE BUT
CONVECTION WILL STILL BE POSSIBLE ON THE TUESDAY AFTERNOON WITH
ISOLATED POTENTIAL FOR A STRONG THUNDERSTORM TO ENTER THE CWA.
AREAS THAT WILL BE FAVOR BY THIS ACTIVITY STILL REMAIN MAINLY
ACROSS THE WESTERN COUNTIES. THIS SYSTEM WILL THEN MOVE NORTHEAST
ACROSS THE CENTRAL PLAINS AND UPPER MID WEST WHILE ANOTHER TROUGH
DIGS ALONG THE CA COAST WHICH WILL CREATE A STRONGER PRESSURE
GRADIENT EAST OF THE SIERRA MADRE AND INTO DEEP SOUTH TEXAS. THE
GRADIENT AS IT STRENGTHENS SO WILL THE SE WINDS ACROSS THE AREA
WITH LOW LEVEL MOISTURE ON THE INCREASE BUT WILL NOT BE AS DEEP
MOISTURE WHICH WILL MAINLY INCREASE CLOUD COVER AND COULD ENHANCE
A ISOLATED SHOWERS THROUGH THE END OF THE WEEK. TEMPERATURES WILL
GRADUALLY INCREASE EACH DAY WITH HIGH`S IN THE MID TO UPPER 80S
AND NEAR 90 DEGREES ALONG THE INTERNATIONAL BORDER. BY THE END OF
THE WEEK...THE UPPER TROUGH BEGINS TO LIFT NORTHEAST AS IT BECOMES
A CLOSED LOW. THIS WILL ENHANCE THE DIFFLUENCE FLOW ALOFT SIMILAR
PATTERN AS THE PREVIOUS LOW PRESSURE. AS A RESULT ..INCREASE THE
POTENTIAL FOR ISOLATED SHOWERS AND THUNDERSTORMS OVER THE SIERRA
MADRE AND INTO THE WESTERN COUNTIES LATE FRIDAY AND SATURDAY
AFTERNOON.

MARINE.../TONIGHT THROUGH SUNDAY NIGHT/...SURFACE HIGH PRESSURE OVER
THE NORTHERN GULF OF MEXICO WILL CONTINUE TO SLIDE EAST TONIGHT AND
SUNDAY. LIGHT SOUTHEASTERLY WINDS TONIGHT WILL BECOME MORE MODERATE
ON SUNDAY WITH SEAS BUILDING FROM 2 TO 3 FEET TONIGHT TO 2 TO 4 FEET
SUNDAY AND SUNDAY NIGHT.

MONDAY THROUGH SATURDAY...THE SOUTHEAST FLOW WILL BE IN CONTROL FOR
MUCH OF THE LONG TERM PERIOD WITH A SERIES OF UPPER LEVEL DISTURBANCES
MOVING ACROSS THE FOUR CORNERS AND INTO THE CENTRAL PLAINS. THE SYSTEM
WILL REMAIN TO THE NORTH BUT WILL STILL ENHANCE CONVECTION INLAND
OVER DEEP SOUTH TEXAS. THE GRADIENT WILL STRENGTHEN DURING THE DAY
KEEPING A MODERATE SE FLOW ACROSS THE GULF WATERS THROUGH THE END
OF THE WEEK. THE SEAS WILL BUILD CLOSE TO 6 FEET LATE TUESDAY DUE
TO THE LONG SE FETCH AND INCREASE IN WINDS. SCEC CONDITIONS WILL
BE POSSIBLE TUESDAY AND BY THE END OF THE WEEK.
&&

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

$$

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