Area Forecast Discussion
Issued by NWS Brownsville, TX

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS64 KBRO 192338
AFDBRO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
638 PM CDT TUE MAY 19 2015

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

&&

.AVIATION...LOW LEVEL INVERSION TO STRENGTHEN THIS EVENING
TRAPPING ABUNDANT LOW LEVEL MOISTURE BELOW 3K FEET. MVFR CIGS
DEVELOPING NEAR KBRO TO INCREASE IN COVERAGE AND SPREAD THIS
EVENING AND OVERNIGHT. THE LOWER CIGS TO MIX OUT AFTER SUNRISE
WEDNESDAY WITH VFR CONDITIONS PREVAILING WEDNESDAY. GUSTY
SOUTHEAST WINDS TO DIMINISH THROUGH THE EVENING INCREASING ONCE
AGAIN WEDNESDAY WITH GUSTS UP TO 25 KNOTS.

&&

.PREV DISCUSSION... /ISSUED 255 PM CDT TUE MAY 19 2015/

SHORT TERM /NOW THROUGH WED NIGHT/...THE 500 MB PATTERN OVER
NORTHERN MEXICO AND SOUTHERN TEXAS WILL BE DOMINATED BY A DEEP
TROUGH AXIS NOW LOCATED OVER THE SOUTHWESTERN U.S. THIS TROUGH
WILL LIFT OUT TO THE NORTHEAST TONIGHT AND WED WHICH WILL ALLOW A
LITTLE DRIER AND MORE STABLE REGIME TO BUILD OVER DEEP SOUTH TX
INTO WED. MOST OF THE DEEPER LAYER MOISTURE WILL REMAIN CONFINED
TO THE NORTH AND WEST OF THE BRO CWA THROUGH WED NIGHT WITH A
COUPLE OF DECENT POCKETS OF 500 MB PV PASSING ACROSS DEEP SOUTH TX
FROM THE W-WSW. EXPECT MOST OF THE BRO CWA TO REMAIN RAINFREE
THROUGH TOMORROW NIGHT. HOWEVER SOME PATCHY CONV CANNOT BE RULED
OUT ACROSS THE FAR WESTERN COUNTIES LATE TOMORROW AFTERNOON INTO
TOMORROW EVENING. SO WILL INCLUDE SOME 20 TO 30 % POPS ACROSS THE
FAR REACHES OF THE CWA. CURRENTLY KBRO RADAR SHOWS SOME PATCHY
CONV FIRING UP OVER THE HIGHER TERRAIN OF NORTHEAST MEX. BELIEVE
THAT THIS CONV WILL NOT MAKE IT OVER THE RGV AS THE 12Z BRO
SOUNDING THIS MORNING INDICATED A CAPE OF ONLY 2813 J/KG WITH A
PWAT OF 1.8 INCHES.

EXPECT FAIRLY STATUS QUO TEMPS TO CONTINUE ACROSS THE DEEP SOUTH TX
AS 500 MB RIDGING BUILDS OVER THE U.S./MEX BORDER REGION AS THE 500
MB TROFFING OVER THE DESERT SW LIFTS OUT. THE SHORT TERM MAV/MET AND
ECMWF TEMP GUIDANCE ARE IN PRETTY CLOSE AGREEMENT BUT WILL LEAN MORE
TOWARDS AT MAV/ECMWF BLEND WHICH IS A BIT WARMER VERSUS THE MET
NUMBERS. REGARDLESS OVERALL TEMPS WILL REMAIN ABOVE CLIMO.

LONG TERM /THURSDAY THROUGH MONDAY/...H5 LOW WILL MOVE
SOUTHWARD ALONG THE PACIFIC COAST THEN TURN NORTHEASTWARD ACROSS
THE FOUR CORNERS EARLY THIS WEEKEND AND INTO THE DAKOTAS MONDAY
WHERE IT WILL BECOME ABSORBED INTO THE FLOW. ALL THE WHILE MID
LEVEL HIGH WILL BUILD ACROSS THE GULF OF MEXICO INTO THE
SOUTHEASTERN CONUS. EARLY ON A WEAK SFC COLD FRONT WILL BE DRAPED
ACROSS CENTRAL TEXAS BUT WILL WASH OUT BY FRIDAY AS MID LEVEL
RIDGING BUILDS OVERHEAD AHEAD OF WESTERN CONUS LOW AND LITTLE
UPPER SUPPORT. CONTINUED SOUTHWESTERLY FLOW ALOFT WILL CONTINUE TO
SPARK CONVECTION OVER THE HIGHER TERRAIN EACH AFTERNOON AND
EVENING THEN MOVE OFF THE MOUNTAINS TOWARDS SOUTH/DEEP SOUTH
TEXAS. BETTER CHANCES OF EXPERIENCING PRECIPITATION AT THIS POINT
WILL BE FRIDAY AS AN EMBEDDED S/W TROUGH MOVES ACROSS THE AREA
WHICH MAY HELP LEAD CONVECTION INTO THE CWA THEN RESIDUAL
BOUNDARIES WILL HELP SPARK NEW CONVECTION. THERE IS A MARGINAL
RISK FOR SEVERE PER SPC FOR FRIDAY FOR DEEP SOUTH TEXAS. A SIMILAR
SETUP IS POSSIBLE SUNDAY BUT THE BETTER SUPPORT WILL BE NORTH OF
THE AREA BUT A FEW ISOLATED STORMS COULD CREEP INTO THE FAR WEST
AND NORTHERN RANCHLANDS. NO CHANGES MADE TO TEMPERATURES...STILL
EXPECTING UPPER 80S TO LOWER 90S FOR HIGHS THROUGH THE EXTENDED.

MARINE /NOW THROUGH WED NIGHT/...RELATIVELY COOLER BAY AND SURF
WATER TEMPS IN THE UPPER 70S TO LOWER 80S WILL TEND TO LIMIT THE
SURFACE MARINE WINDS OVER THE LOWER TX MARINE AREAS THROUGHOUT THE
SHORT TERM PERIOD AS THE VERY WARM SE SURFACE FLOW CONTINUES.
EXPECT SCEC CONDITIONS TO CONTINUE THROUGH TONIGHT BUT THEN THE
PGF WILL BE WEAKENING A BIT INTO WED AND WED NIGHT.

THURSDAY THROUGH SATURDAY...GENERALLY MODERATE SOUTHEAST
WINDS THROUGH THE PERIOD AND MODERATE SEAS. NO ADVISORIES EXPECTED
AT THIS TIME BUT WINDS WILL INCREASE SOMEWHAT SATURDAY WHICH MAY
LEAD TO SMALL CRAFT EXERCISE CAUTION CONDITIONS ON THE LAGUNA DURING
THE DAY.

&&

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

$$

THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV

59/99



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.