674
FXUS64 KBRO 031613 AAB
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1013 AM CST SUN MAR 3 2013

.DISCUSSION...SURFACE WINDS PICKING UP AS HEATING UNDER FULL SUN
LIFTS TEMPERATURES AND GETS LOW LEVEL MIXING GOING. 10 AM TEMPS
ARE OVERACHIEVING A LITTLE AND MADE MINOR ADJUSTMENTS UPWARD TO
THE HOURLY AND MAX TEMPERATURE FORECAST FOR TODAY WITH SOUTHERLY
WINDS OVER THE CENTRAL AND WESTERN PART OF THE CWA ON A WARM/DRY
OVERLAND TRAJECTORY. EXPECT WIND SPEEDS TO INCREASE LATER THIS
AFTERNOON AS THE LOWER LEVEL PRESSURE GRADIENT TIGHTENS. 12Z
NAM/HRRR/RAP AND THE SYNOPTIC PICTURE AGREE ON MARKEDLY INCREASING
WINDS OVER THE GULF TONIGHT AND WENT AHEAD AND HOISTED A SMALL
CRAFT ADVISORY FOR TONIGHT AND TOMORROW WILL LET LATER SHIFTS
EXTEND IT AS THE EVENT UNFOLDS. NO OTHER CHANGES AT THIS TIME. /68-JGG/

&&

.MARINE...A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE GULF
WATERS ALONG THE LOWER TEXAS COAST FROM THIS EVENING THROUGH THE
OVERNIGHT TONIGHT AND MONDAY FOR STRONG SOUTH WINDS. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED ON MONDAY FOR THE LAGUNA MADRE AS
WELL...AND THE ADVISORIES WILL LIKELY BE EXTENDED THROUGH TUESDAY
AND EARLY WEDNESDAY DUE TO STRONG SOUTH WINDS...AND THEN NORTH
WINDS BEHIND A PASSING FRONT. /68-JGG/

&&

.PREV DISCUSSION... /ISSUED 512 AM CST SUN MAR 3 2013/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...VFR CONDITIONS WITH CLEAR SKIES TODAY AND TONIGHT.
SOUTHEAST WINDS TO INCREASE THIS AFTERNOON WITH SOME GUST BETWEEN
20 AND 25 KNOTS ALONG THE HIGHWAY 77 CORRIDOR. SOUTHEAST TO SOUTH
WINDS INCREASE TONIGHT WITH GUSTS AROUND 20 KNOTS SPREADING
WESTWARD. LOW LEVEL JET STRENGTHENING TO 40 KNOTS BETWEEN 2000
AND 4000 FEET AFTER 06Z MONDAY.

PREV DISCUSSION... /ISSUED 346 AM CST SUN MAR 3 2013/

SHORT TERM /TODAY THROUGH MONDAY/...THE WIND MACHINE GETS
TURNED ON LATER TODAY THEN GETS CRANKED ON HIGH MONDAY. SURFACE
HIGH GETS SHUNTED EAST AS MID LEVEL RIDGE BUILDS OVER EASTERN
TEXAS. UPSTREAM TROUGH MOVES INTO NORTHERN ROCKIES WITH LEE LOW
DEEPENING ACROSS THE FRONT RANGE. GRADIENT TIGHTENS THIS AFTERNOON
AND CONTINUES TO STRENGTHEN TONIGHT AND THROUGH THE DAY MONDAY.
EXPECT BREEZY CONDITIONS TO DEVELOP ACROSS THE COASTAL COUNTIES
THIS AFTERNOON THEN SPREAD ACROSS ALL AREAS BY THIS EVENING AND
PERSIST OVERNIGHT. MODELS SUGGEST SURFACE INVERSION DEVELOPING
ALONG WITH A BROAD 925MB LOW LEVEL JET OF 35 TO 40 KNOTS. THIS JET
MIXES TO THE SURFACE ON MONDAY EARLY MORNING AND CONTINUES THROUGH
THE AFTERNOON. THE 77 CORRIDOR LOOKS TO BE THE FAVORED AREA FOR A
WIND ADVISORY WITH EASTERN PORTIONS OF HIDALGO SEEING WINDY
CONDITIONS. GFS MAV IS THE HIGHEST ON THE WINDS BUT MODEL
CONSENSUS OF DEVELOPING STRONG WINDS INCREASES CONFIDENCE.

TEMPERATURES TO SEE A STEADY CLIMB THROUGH MONDAY AS THE SOUTHERLY
WINDS INCREASE. TODAY THE CWA IS STILL ON TRACK TO SEE A 5 TO 8
DEGREE INCREASE OVER YESTERDAY WITH MOST AREAS CLIMBING INTO THE 80S
WITH EXCEPTION TO THE COASTAL AREA. MUCH MILDER TONIGHT WITH SOME
GULF MOISTURE INCREASING AND WINDS REMAINING MODERATE AND GUSTY.
EVEN WITH CLEAR SKIES MINIMAL RADIATIONAL COOLING AFFECT EXPECTED
ESPECIALLY ACROSS THE COASTAL COUNTIES WHERE WINDS TO BE THE
HIGHEST. THEN FOR MONDAY MODELS ONCE AGAIN AGREE WITH A MODEST
HEAT SPIKE AS 850-700MB WINDS TURN SW-W THIS LEADS TO DOWNSLOPING
AND 850MB TEMPERATURES NEARING 20C. GOING FORECAST TRENDS WITH THE
WARMER EUROPEAN MODEL WHICH TAKE TEMPERATURES INTO THE LOW TO MID
90S OUT WEST...NEAR 90 ACROSS THE MID VALLEY AND MID TO UPPER 80S
IN THE LOWER VALLEY.

AS MENTIONED GULF MOISTURE BEGINS TO INCREASE WITH DEW POINTS IN THE
EAST RECOVERING INTO THE 40S TODAY AND APPROACHING MID 50S TONIGHT.
THESE INCREASE IS AT THE SURFACE WITH LITTLE INCREASE DEPTH SEEN
WITHIN THE MODEL CONSENSUS. SKIES TO REMAIN CLEAR TO MOSTLY CLEAR
THROUGH THE PERIOD.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...ZONAL FLOW ALOFT
OVER DEEP SOUTH TEXAS WITH A SURFACE HIGH OVER FLORIDA AND A COLD
FRONT OVER NORTHERN TEXAS TO START THE PERIOD. COLD FRONT MAKES
QUICK WORK OF TEXAS MOVING THROUGH THE RIO GRANDE VALLEY BY
TUESDAY NIGHT. SFC HIGH PRESSURE WILL BUILD IN FROM THE NORTH
WEDNESDAY WITH NORTHERLY WINDS AND THE COOLEST MAXES FOR THE
WEEK...UPPER 60S TO MIDDLE 70S. SFC HIGH MOVES EAST WITH EASTERLY
WINDS WEDNESDAY NIGHT AND SOUTHEASTERLY WINDS THURSDAY THROUGH
SATURDAY. ATTENTION THEN TURNS TO 500MB TROUGH/LOW DIVING DOWN
THROUGH CALIFORNIA THURSDAY/FRIDAY AND INTO THE DESERT SOUTHWEST
SATURDAY. MODEL DIFFERENCES APPEAR SATURDAY WITH RESPECT TO LOW
PLACEMENT...ECMWF IS FURTHER NORTH WITH PLACEMENT OVER COLORADO BY
THE END OF THE PERIOD WITH THE GFS FURTHER SOUTH WITH PLACEMENT
OVER SOUTHERN ARIZONA/NEW MEXICO. BETTER CONSISTENCY LIES WITH THE
GFS AND LEANED FORECAST TOWARDS THIS MODEL.

BREEZY CONDITIONS WILL BE ONGOING EARLY MONDAY NIGHT WITH WINDS
DECREASING AFTER SUNSET. BREEZY CONDITIONS CAN BE EXPECTED TUESDAY
BEHIND THE FRONTAL PASSAGE THROUGH THE EARLY EVENING HOURS. RELATIVE
HUMIDITY VALUES WILL FALL TO THE MIDDLE TEENS TO MIDDLE 20S TUESDAY
AND WEDNESDAY...LOWEST VALUES ACROSS ZAPATA/JIM HOGG/STARR COUNTIES.
20 FOOT WINDS PRECLUDE RFW AT THIS TIME BUT INCREASED FIRE DANGER
EXPECTED. BREEZY CONDITIONS EXPECTED FRIDAY AND SATURDAY AHEAD OF
THE NEXT DEVELOPING STORM SYSTEM.

MARINE /TODAY THROUGH MONDAY/...LIGHT WINDS THIS MORNING TO VEER
SOUTHEAST LATER TODAY AND BEGIN TO INCREASE. PRESSURE GRADIENT
INCREASES TONIGHT AS LOW PRESSURE DEVELOPS OVER THE SOUTHERN
PLAINS. SOUTH WINDS QUICKLY INCREASE OFFSHORE BY OR SHORTLY AFTER
MIDNIGHT AND A SMALL CRAFT ADVISORY COULD BE ISSUED FOR THE
OVERNIGHT PERIOD. THE PRESSURE GRADIENT STRENGTHENS FURTHER MONDAY
WITH ALL COASTAL WATERS SEEING SMALL CRAFT ADVISORY CONDITIONS.

MONDAY NIGHT THROUGH SATURDAY...
SMALL CRAFT ADVISORIES WILL LIKELY BE ONGOING TO START THE PERIOD.
ADDITIONAL ADVISORIES WILL BE POSSIBLE TUESDAY AHEAD OF A COLD FRONT
AND WEDNESDAY BEHIND THE COLD FRONT. HIGH PRESSURE BUILDS ACROSS THE
COASTAL WATERS THURSDAY WITH CONDITIONS IMPROVING. IMPROVEMENTS WILL
BE SHORT LIVED AS WINDS/SEAS WILL INCREASE ONCE AGAIN AHEAD OF A
DEVELOPING LOW PRESSURE SYSTEM FRIDAY AND SATURDAY. SMALL CRAFT
EXERCISE CAUTION POSSIBLE DURING THIS TIME FRAME.

FIRE WEATHER...
ELEVATED FIRE DANGER IS EXPECTED TODAY FOR ALL AREAS WITH A FIRE
WEATHER WATCH GOING TO BE ISSUED FOR AREAS WEST OF HIGHWAY 281
MONDAY. A SLOW RECOVERY OF RELATIVE HUMIDITY AND INCREASING SOUTH
WINDS LATER TODAY TO KEEP A HIGHER RISK OF FIRE SPREAD. HUMIDITY
WILL BE HIGHER IN THE EAST ALONG WITH HIGHER WIND SPEEDS WHILE THE
WEST TO SEE LOWER HUMIDITY BUT A SLOWER INCREASE IN THE WINDS.
OVERALL THERE REMAINS A DANGER WITH THE EXTREMELY DRY FUELS. WINDS
INCREASE AND TURN S-SSW ON MONDAY AS WITH DEEPENING LOW PRESSURE
OVER NORTH TEXAS. THIS SHOULD RESULT IN MODEST DOWNSLOPING
CONDITIONS TO DEVELOP OVER THE WESTERN RANCHLANDS. AN INCREASE IN
TEMPERATURES TOPPING 90 DEGREES AND A MIXING OUT OF LIMIT SURFACE
MOISTURE TO ALLOW FOR DEW POINTS TO CRASH AND HUMIDITY TO DROP
CONSIDERABLE. SURFACE WINDS ARE FORECAST TO BE STRONG ENOUGH TO
WARRANT A WATCH FOR THE AFTERNOON HOURS. AREAS TO SEE THE MOST
IMPACT WILL BE STARR AND HIDALGO COUNTIES WITH LESSOR IMPACT ACROSS
JIM HOGG AND BROOKS COUNTIES WHERE WINDS MIGHT NOT BE AS STRONG.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...FIRE WEATHER WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING
     FOR TXZ248>250-252-253.

GM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST MONDAY
     FOR GMZ150-155-170-175.

&&

$$

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