000
FXUS64 KBRO 201814 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
114 PM CDT SUN APR 20 2014

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

&&

.AVIATION...VSBL SATL IMAGERY SHOWS PLENTY OF SC/CU FIELDS IN
PLACE OVER DEEP SOUTH TX AS THE MOIST SE SURFACE FLOW CONTINUES TO
ADVECT IN GULF MOISTURE. THE DAYTIME HEATING AND DECENT LOW LEVEL
MIXING FROM THE SOUTHEAST WINDS WILL MAINTAIN VFR CONDITIONS
THROUGHOUT THE AFTERNOON AND EARLY EVENING HOURS. NAM FORECAST
SOUNDINGS THEN SHOW A BETTER POTENTIAL FOR LOWER CEILINGS
OVERNIGHT AS A FAIRLY MOIST LAYER DEVELOPS FROM 1 TO 2 KFT FROM 06
TO 12Z MON. SO WILL GO WITH SOME MVFR/IFR CEILINGS DURING THE
OVERNIGHT HOURS. AS THE LOW LEVEL MIXING INCREASES TOMORROW
MORNING AFTER SUNRISE EXPECT THE CEILINGS FOR THE LOWER RGV
AIRPORTS TO INCREASE BACK UP TO VFR LEVELS LATER IN THE CURRENT
TAF PERIOD.

&&

.PREV DISCUSSION... /ISSUED 409 AM CDT SUN APR 20 2014/

SHORT TERM /NOW THROUGH MONDAY/...
CURRENT WATER VAPOR IMAGERY SHOWS THE 500 MB LOW ACROSS NORTHEASTERN
NEW MEXICO THIS MORNING. THIS LOW IS EXPECTED TO FILL AND LIFT TO
THE NORTHEAST LATER TODAY. THE BRO SOUNDING FROM EARLIER THIS
EVENING INDICATES PRECIPITABLE WATERS OF 1.42 INCHES. SURFACE
OBSERVATIONS AND SATELLITE IMAGERY SHOWS STRATOCU ACROSS MUCH OF THE
RIO GRANDE VALLEY AND DEEP SOUTH TEXAS  THIS MORNING DUE TO MOIST
SOUTHEASTERLY WINDS ADVECTING HIGHER MOISTURE IN THE AREA.

WILL CONTINUE TO MENTION SLIGHT CHANCE OF THUNDERSTORMS IN THE WEST
TODAY AS PRECIPITABLE WATER VALUES EXCEEDING 1.5 INCHES IN SOME
AREAS. HOWEVER...STRONG CAPPING SHOULD KEEP ANY CONVECTION VERY
LIMITED. MOSTLY CLOUDY SKIES WILL KEEP HIGH TEMPERATURES IN THE LOW
80S ACROSS MUCH OF THE AREA TODAY. CONVECTION MAY DEVELOP ACROSS THE
HIGHER MEXICAN TERRAIN THIS EVENING AND POSSIBLY ACROSS THE RIO
GRANDE RIVER. SO WILL CONTINUE TO MENTION A SLIGHT CHANCE OF
THUNDERSTORMS ACROSS THE WEST. OTHERWISE...MOSTLY CLOUDY SKIES WITH
LOW TEMPERATURES IN THE MID TO UPPER 60S FOR TONIGHT. LOW LEVEL
MOISTURE AND LIGHT WINDS SHOULD RESULT IN PATCHY FOG ACROSS THE
NORTHERN RANCHLANDS TONIGHT. FOG IS NOT EXPECTED ACROSS THE VALLEY
OVERNIGHT AS LOW CLOUDS AND SLIGHTLY STRONGER WINDS SHOULD INHIBIT
FOG FORMATION. DRY AND WARMER ON MONDAY AS THE MID LEVEL TROUGH
MOVES OUT OF THE REGION. HIGH TEMPERATURES MONDAY WILL RANGE FROM
THE MID 70S ALONG THE COAST TO THE MID TO UPPER 80S FARTHER INLAND
DUE TO A LITTLE LESS CLOUD COVER.  /63/

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
UPPER TROUGHINESS THAT EXTENDS SOUTHWEST INTO THE ARKLATEX IS
EXPECTED TO DAMPEN AS IT HEADS TOWARD THE SOUTHEAST UNITED STATES
TUESDAY.  A FEW SHOWERS MAY BE SEEN AS THE TAIL END OF THE TROUGH
EXITS THE REGION...BUT GIVEN FORECAST SOUNDINGS AND MINIMAL SYNOPTIC
SCALE FORCING...ANY COVERAGE WILL BE VERY LIMITED.  SHORTWAVE
RIDGING SHOULD BUILD INTO THE REGION BEHIND THE TROUGH...ALLOWING
GENERALLY DRY WEATHER CONDITIONS TO BE SEEN INTO MID-WEEK.

ATTENTION THEN TURNS TO A RATHER LONGWAVE TROUGH THAT HAS MOVED
ONSHORE ALONG THE PACIFIC COAST.  SHORTWAVE RIDGING OVER OUR AREA
WILL LIKELY BE FLATTENED SOMEWHAT AS THE NEW TROUGH HEADS INTO THE
INTERMOUNTAIN WEST WEDNESDAY...AND PUSHES A COLD FRONT INTO THE HIGH
PLAINS.  IT DOESN`T LOOK LIKE THIS FRONT WILL MAKE IT AS FAR SOUTH
AS THE IH-10 CORRIDOR...THANKS TO THE EXPECTED NEARLY ZONAL FLOW
ALOFT DUE TO DAMPENED SHORTWAVE RIDGING.  TEMPERATURES SHOULD BE
ABOVE SEASONAL AVERAGES (ROUGHLY MIDDLE 80S/UPPER 60S) THROUGH MUCH
OF THE LONG TERM PERIOD...WITH THE WARMEST HIGHS ALONG AND WEST OF
IH-69C/US-281.

SO IT LOOKS LIKE OUR MAIN WEATHER IMPACT FROM THIS SYSTEM WILL
LIKELY COME IN THE FORM OF BREEZY CONDITIONS TOWARD THE LATTER HALF
OF THE WEEK FROM THE INCREASED PRESSURE GRADIENT.  AN INCREASE IN
CONVECTION OVER THE MOUNTAINS OF NORTHERN MEXICO MAY ALSO BE SEEN BY
THURSDAY...AS A SURFACE TROUGH AND WEAK PERTURBATIONS INTERACT WITH
POOLING BOUNDARY LAYER MOISTURE.  FOR NOW...THOUGH...IT DOESN`T LOOK
LIKE ANY CONVECTION SHOULD POSE A SIGNIFICANT RISK TO ANY PART OF
OUR FORECAST AREA. /53/

MARINE...

TONIGHT THROUGH MONDAY...
BUOY 42020 REPORTED EAST-SOUTHEAST WINDS AROUND 12 KNOTS GUSTING TO
AROUND 16 KNOTS WITH SEAS SLIGHTLY OVER 3 FEET WITH A PERIOD OF 5
SECONDS AT 3 AM CDT/8 UTC. HIGH PRESSURE CENTERED ALONG THE NORTHERN
GULF COAST THROUGH THE PERIOD WILL RESULT IN GENERALLY MODERATE
WINDS AND SEAS THROUGH MONDAY. SMALL CRAFT MAY NEED TO EXERCISE
CAUTION ON THE LAGUNA MADRE THIS AFTERNOON DUE TO BREEZY SOUTHEAST
WINDS. /63/

MONDAY NIGHT THROUGH THURSDAY...
DIMINISHING WINDS AND SEAS SHOULD BE SEEN MONDAY NIGHT AS RIDGING
BUILDS ACROSS THE MARINE AREA...ALLOWING LIGHT WINDS AND LOW SEAS TO
BE SEEN INTO MID-WEEK.  A STORM SYSTEM IS EXPECTED TO MOVE INTO THE
CENTRAL/SOUTHERN PLAINS AROUND THURSDAY.  AN INCREASED PRESSURE
GRADIENT WILL LIKELY RESULT...AND WE`LL PROBABLY SEE STRONGER
WINDS.  I ORIGINALLY THOUGHT ABOUT NUDGING WAVE HEIGHTS UPWARD A BIT
FOR THE END OF THE WEEK THIS MORNING...BUT I`M THINKING ANY
(SIGNIFICANT) RESPONSE TO INCREASED WIND SPEEDS MAY BE MINIMAL.
REGARDLESS...THE STRONGER WINDS MAY NECESSITATE SMALL CRAFT
EXERCISING CAUTION OR THE POSTING OF SMALL CRAFT ADVISORIES FOR THE
LATTER HALF OF THE WEEK. /53/

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  78  69  79  67 /  10  10  10  10
BROWNSVILLE          80  68  81  66 /  10  10  10  10
HARLINGEN            82  67  83  66 /  10  10  10  10
MCALLEN              83  69  86  69 /  10  10  10  10
RIO GRANDE CITY      84  68  87  68 /  20  20  10  10
SOUTH PADRE ISLAND   75  69  76  67 /  10  10  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...60
LONG TERM...55
GRAPHICAST/UPPER AIR...MARTINEZ