Area Forecast Discussion
Issued by NWS Brownsville, TX

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 212341 AAA
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
641 PM CDT MON JUL 21 2014

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

&&

.AVIATION...VFR TO PREVAIL MUCH OF THE EVENING BEFORE MVFR STRATUS
BEGINS TO DEVELOP AFTER 04Z BUT NOT IMPACTING FLIGHTS UNTIL
BETWEEN 06-09Z. THE STRATUS DEVELOPS AT OR BELOW THE SURFACE
INVERSION AT 1500-2000 FEET HOWEVER WITH DRIER AIR JUST ABOVE THIS
LEVEL STRATUS LOOKS TO MORE SCT-BKN UNTIL A FEW HOURS EITHER SIDE
OF SUNRISE WHEN BKN TO OCCASIONALLY OVC CONDITIONS DEVELOP.
CLOUDS TO MIX OUT MID MORNING TUESDAY WITH VFR RESUMING. GUSTS
20-25 KNOTS UNTIL 02Z THEN WINDS DECOUPLE WITH LIGHT WINDS BY
MIDNIGHT.

&&

.PREV DISCUSSION... /ISSUED 313 PM CDT MON JUL 21 2014/

SHORT TERM /NOW THROUGH TUESDAY NIGHT/...DRIER AIR ABOVE THE
SUBSIDENCE INVERSION...GENERALLY FROM AROUND 925 MB TO 600 MB...IS
MIXING DOWN NICELY THIS AFTERNOON AND LOWERING THE DEWPOINTS...AND
HENCE THE HUMIDITY AND HEAT INDEX...TO SLIGHTLY MORE BEARABLE LEVELS
THAN WE SAW THIS PAST WEEKEND WHERE POCKETS OF THE VALLEY BRIEFLY
ROSE TO 111-113.  WITH HIGH TEMPERATURES EXPECTED TO RANGE FROM 100
TO 105 FROM HIGHWAY 77 WEST...FEELS LIKE TEMPERATURES WILL BE ABOUT
THE SAME OR JUST A TAD HIGHER. STILL A GOOD DEAL OF HAZINESS AROUND
WHICH MAY BE FROM A PERSISTENT PLUME OF SAHARAN DUST THAT STRETCHED
ALL THE WAY INTO THE WESTERN GULF.

FOR THE REMAINDER OF THE PERIOD...REALLY NOT MUCH TO EXPOUND ON.
CLASSIC MID SUMMER 500 MB RIDGE WITH HEIGHTS APPROACHING 600 DM OVER
COLORADO BY TUESDAY AFTERNOON WILL CONTINUE ITS REACH INTO TEXAS AND
NORTHERN MEXICO.  BY TUESDAY NIGHT...THE RIDGE BECOMES JUST A LITTLE
MORE ELONGATED EAST-WEST FROM COLORADO INTO THE MID MISSISSIPPI
VALLEY...ALLOWING A PESKY DISTURBANCE TO BEGIN RETROGRADING FROM
GEORGIA/ALABAMA TOWARD THE MISSISSIPPI/LOUISIANA COAST. MORE ON THE
DISTURBANCE AND ITS POTENTIAL FUTURE IN THE LONG TERM DISCUSSION.

ABOUT THE ONLY IMPACT THE ELONGATING RIDGE HAS ON THE SHORT TERM IS
SOME PATCHY MID LEVEL CLOUDS ROLLING AROUND THE RIDGE ON
TUESDAY...AND A COUPLE DEGREE DROP IN AFTERNOON TEMPERATURES AS THE
ATMOSPHERIC COLUMN COOLS EVER SO SLIGHTLY.  LIGHT TO NEAR CALM WINDS
LATE TONIGHT/EARLY TUESDAY AND AGAIN LATE TUESDAY NIGHT/EARLY
WEDNESDAY SHOULD TRIGGER MENTIONABLE FOG (1-2 MILE VISIBILITY)
ACROSS THE NORTHERN RANCHLANDS WHERE THEY HAVE A BIT MORE SOIL
MOISTURE TO WORK WITH...BUT NO SIGNIFICANT PROBLEMS.
UNFORTUNATELY...FOR THOSE WISHING FOR THE AZURE BLUE TROPICAL SKIES
WHERE YOU CAN SEE `FOREVER`...NO SUCH LUCK.  SAHARAN DUST HAZE WILL
LIKELY BE REPLACED WITH A MORE SMOKY HAZE AS FLOW AROUND THE BROAD
RIDGE MOVE SOME OF THE SMOKE (ALOFT) CLOCKWISE INTO MOST IF NOT ALL
OF TEXAS BEGINNING TUESDAY AND PROBABLY CONTINUING A BIT LONGER.

LONG TERM /WEDNESDAY THROUGH MONDAY/...500 MB RIDGING WILL REMAIN
ANCHORED IN PLACE OVER MUCH OF THE SOUTHWESTERN AND SOUTH CENTRAL
STATES IN ADDITION TO NORTHERN MEXICO THROUGHOUT THE UPCOMING
EXTENDED RANGE PERIOD. A CLOSED LOW IS EXPECTED TO SHEAR OFF OF THE
BROAD AND ELONGATED 500 MB TROUGH AXIS OVER THE EASTERN STATES AND
TRY TO MOVE AROUND THE BASE OF THE RIDGE AXIS TOWARDS THE END OF THE
WEEK AND INTO NEXT WEEKEND. THIS MAY DESTABILIZE THE ATMS SOMEWHAT
AS THE WEEKEND APPROACHES. HOWEVER MEAN RH FIELDS EXPECTED OVER THE
REGION WILL LIKELY REMAIN PRETTY LOW WHICH WILL TEND TO DAMPEN ANY
CONV POTENTIAL DESPITE THE SLIGHT WEAKENING OF THE RIDGE AXIS. SO
WILL LEAVE OUT ANY MENTION OF SIGNIFICANT POPS AT THIS TIME THROUGH
DAY 7.

DUE TO THE COMBINATION OF THE GENERAL STRENGTH OF THE RIDGE AXIS
AND THE EXPECTED ABSENCE OF DECENT MOISTURE LEVELS ALLOWING FOR
PLENTY OF SUNSHINE...EXPECT DAYTIME HIGH TEMPS TO REACH OR EXCEED
GUIDANCE CONSISTENTLY THROUGH DAY SEVEN. SO HAVE LEANED CLOSER TO
THE WARMER ECMWF HIGH TEMPS THROUGH THE PERIOD AS THE MEX NUMBERS
MAY BE UNDERESTIMATING THE POTENTIAL HEAT OVER THE NEXT SEVERAL
DAY.

NHC HAS INCREASED THE POTENTIAL FOR SOME DEVELOPMENT OF THE
SURFACE LOW PRESSURE SYSTEM LOCATED IN THE CENTRAL ATLANTIC. BOTH
THE ECMWF AND GFS MODELS ARE NOT VERY AGGRESSIVE IN THE
DEVELOPMENT OF THIS FEATURE. SATELLITE IMAGERY SHOWS PRETTY
SIGNIFICANT SAHARAN DUST SURROUNDING THIS SURFACE LOW WITH THE
DUST FORMATION EXTENDING WELL WEST INTO THE EASTERN CARIB. WITH
500 MB TROFFING PREVAILING ALONG THE EAST COAST INTO THE WEEKEND
AND EARLY NEXT...THIS FEATURE DOES NOT POSE A THREAT TO THE LOWER TX
COASTLINE. PLEASE REFER TO THE LATEST OUTLOOKS AND STATEMENTS FROM
THE NATIONAL HURRICANE CENTER CONCERNING THE PROGRESS OF THIS
SYSTEM.

MARINE...NOW THROUGH TUESDAY NIGHT...SURFACE HIGH PRESSURE WILL
CONTINUE TO DOMINATE THE ENTIRE GULF THROUGH THE PERIOD.  THE
LOWERING WINDS OVER THE WEEKEND BROUGHT SEAS/SWELLS DOWN BELOW 3
FEET WILL CONTINUE TO DROP INTO TUESDAY NIGHT WITH THE USUAL DIURNAL
TRENDS HOLDING /HIGHER OVER THE GULF AT NIGHT...AND HIGHER OVER THE
LAGUNA DURING THE AFTERNOON/.  IF YOU LIKE SMOOTH TO LIGHT CHOP FOR
FISHING...BOTH TUESDAY AND WEDNESDAY MORNING ARE IDEAL.

WEDNESDAY THROUGH SATURDAY...THE SURFACE RIDGING OVER THE GULF OF
MEX AND THE WESTERN ATLANTIC WILL MAINTAIN FAIRLY STATUS QUO
MARINE CONDITIONS IN PLACE AS A MODERATE S-SE SURFACE FLOW
PREVAILS. A SURFACE LOW EXPECTED TO DEVELOP OVER THE CENTRAL
PLAINS STATES LATE THIS WEEK MAY INCREASE THE PGF A LITTLE
RESULTING IN A BIT STRONGER SURFACE WINDS. THIS COULD REQUIRE A
MENTION OF SOME SCEC CONDITIONS LATE IN THE CWF WORDING. HOWEVER
NO SCA CONDITIONS EXPECTED AT THIS TIME.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  81  93  79  94 /  10  10   0   0
BROWNSVILLE          80  95  78  96 /  10  10   0   0
HARLINGEN            78  98  77  98 /  10  10   0   0
MCALLEN              79 100  79 101 /  10   0   0   0
RIO GRANDE CITY      78 100  77 102 /  10   0   0   0
SOUTH PADRE ISLAND   81  88  80  90 /  10  10   0   0

&&

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

$$

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

59/53




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