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 280207 AAB
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
907 PM CDT SUN JUL 27 2014

.DISCUSSION...UPDATED FOR LATEST MARINE DISCUSSION BELOW.

&&

.MARINE...UPDATED TO REFLECT THE EXPIRATION OF THE SMALL CRAFT
ADVISORY FOR THE LAGUNA MADRE. WINDS DECREASED DUE TO A WEAKER
PRESSURE GRADIENT.

&&

.PREV DISCUSSION... /ISSUED 637 PM CDT SUN JUL 27 2014/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...VFR TAFS THE NEXT 24 HOURS. MID LEVEL RIDGING ALOFT
AND SURFACE HIGH PRESSURE REMAIN DOMINANT. CLEAR SKIES AND LIGHT
WINDS TONIGHT WILL BECOME MOSTLY SUNNY ON MONDAY...WITH MDT SOUTH
SOUTHEAST WINDS.

PREV DISCUSSION... /ISSUED 245 PM CDT SUN JUL 27 2014/

.AND THESE LOOKED REASONABLE (AND WERE RETAINED) GIVEN THE DRIER
AIR EXPECTED TO MOVE IN.

LONG TERM /TUESDAY THROUGH SUNDAY/..
HOT/HUMID/DRY ALL WORK WEEK...BREEZIER THURSDAY AND FRIDAY...SOME
PRECIP CHANCE SAT/SUN BUT TRENDING DRIER RUN TO RUN.

LARGE SCALE PATTERN GOVERNING THE REGIONS WEATHER CHANGES VERY
LITTLE TUESDAY THROUGH WEDNESDAY. UPPER LEVEL RIDGING REMAINS
ANCHORED OVER WEST TEXAS WITH AN EXTENSION EAST SOUTHEASTWARD INTO
THE WESTERN GULF OF MEXICO WITH TROUGHING OVER THE EASTERN CONUS.
THIS KEEPS THE BERMUDA HIGH WELL TO THE EAST OF FLORIDA AND LEADS TO
A RELATIVELY WEAK LOCAL PRESSURE GRADIENT. WINDS WILL REMAIN BREEZY
FUELED PRIMARILY BY LAND/SEA THERMAL DIFFERENCES. TEMPERATURES WILL
REMAIN HOT WITH HUMIDITY LEVELS REMAINING UNCOMFORTABLE AS LOW LAYER
MOISTURE IS RECHARGED BY ONSHORE SOUTHEASTERLY FLOW. HIGHS IN THE MID
TO UPPER 90S COASTAL TO 100 TO 105 INLAND WERE INHERITED AND AGREE
WITH FAIRLY TIGHTLY CLUSTERED ENSEMBLE AND BIAS CORRECTED
TEMPERATURE GUIDANCE AND CHANGED BOTH MAXES AND MINS VERY LITTLE IN
THIS TIME FRAME WITH NO CHANCE OF PRECIP.

THURSDAY THE ONLY APPRECIABLE DIFFERENCE IS THAT LEE TROUGHING
APPEARS TO GROW A LITTLE MORE INTENSE AS NORTHWESTERLY FLOW AT
250/500MB DIGS INTO CENTRAL TEXAS. THIS SHOULD INCREASE LOCAL WINDS
BACK INTO THE 15 TO 25 MPH RANGE WITH GUSTS OF 30 TO 35MPH IN THE
AFTERNOON. TEMPERATURES WILL CHANGE LITTLE FROM PREVIOUS DAYS WITH
500MB HEIGHTS STILL AROUND 592 TO 594 DAM.

FRIDAY A JET MAXIMUM WORKS DOWN THE WESTERN SIDE OF BROAD EASTERN US
TROUGHING AND CARRIES A FEW EMBEDDED SHORTWAVES IN THE STRONGER
NORTHWEST FLOW. THIS APPEARS TO INITIATE SOME PRECIP/ACTIVITY TO OUR
NORTHEAST BUT THE NORTHWESTERLY STEERING FLOW DOES NOT QUITE REACH
INTO THE CWA AND LEFT THE FORECAST DRY BUT STILL HOT AND BREEZY.
COLUMN RH DOES NOT CHANGE MUCH BUT COLUMN THICKNESS VALUES DROP A
FEW DM AND FOLLOWED THE GUIDANCE TRENDS FOR A DEGREE OR TWO COOLER
MAXES ON FRIDAY.

SATURDAY SUBTLE DIFFERENCES IN THE GFS/ECMWF RESULT IN DIFFERENT
FORECASTS FOR SENSIBLE WX. THE GFS IS STRONGER WITH 250/500MB
RIDGING TO THE EAST AND THIS SHIFTS THE DIRECTION OF STRONGER
NORTHEASTERLY FLOW TO THE TEXAS COASTAL BEND REGION WHEREAS THE
ECMWF SHOWS THE RIDGING RETREATING AS DEEPER AND STRONGER
NORTHWESTERLIES PUSH INTO THE AREA. THIS MOVES A SHEAR
ZONE/BOUNDARY/AREA OF UNSETTLED WEATHER OVER THE AREA SATURDAY AND
SUNDAY AND THE ECMWF GENERATES A FAIR AMOUNT OF CONVECTION/PRECIP.
THE GFS DELAYS THIS PROCESS UNTIL SUNDAY AND KEEPS SATURDAY BREEZY
AND DRY.  MODEL TRENDS FROM 12 TO 24 HOURS LEAN DRIER WITH THE
RIDGING HOLDING AND THE SEASON HAS PLAYED OUT THAT WAY SO FAR SO
WORKED THE FORECAST IN THE DRIER DIRECTION BUT DID LEAVE SLIGHT
CHANCE POPS IN SATURDAY AFTERNOON AND SUNDAY. IF THE STRONGER
NORTHWESTERLY FLOW SOLUTION EVENTUALLY VERIFIES EITHER SATURDAY OR
SUNDAY THAT IS A PRETTY CLIMATOLOGICALLY FAVORABLE PATTERN FOR
SUMMERTIME SHOWERS AND THUNDERSTORMS SO WILL WATCH CLOSELY IN THE
COMING DAYS. KEPT MAXES A BIT WARMER THAN GUIDANCE CONSENSUS ON
SATURDAY BUT COOLED THEM ON SUNDAY OWING TO DEEPER HUMIDITY...LOWER
THICKNESSES AND THE POSSIBILITY OF CONVECTION. /68-JGG/

MARINE...
NOW THROUGH MONDAY NIGHT...BUOY 42020 REPORTED SOUTH WINDS
AROUND 16 KNOTS GUSTING TO AROUND 18 KNOTS WITH SEAS OF 3 FEET WITH
A PERIOD OF 5 SECONDS AT 13 CDT/18 UTC. A SMALL CRAFT ADVISORY FOR
WINDS REMAINS IN EFFECT FOR THE LAGUNA MADRE UNTIL 8 PM CDT TONIGHT.
OTHERWISE...SURFACE HIGH PRESSURE BECOMING CENTERED A LITTLE CLOSER
TO THE WESTERN GULF OF MEXICO WILL CAUSE A SLIGHT DECREASE IN WINDS
AND DROP IN SEAS ALONG THE LOWER TEXAS DURING THE FORECAST PERIOD.
NO ADDITIONAL SMALL CRAFT ADVISORIES ARE EXPECTED...AND SMALL CRAFT
EXERCISE CAUTION IS NOT LIKELY TO BE NEEDED.

TUESDAY THROUGH FRIDAY...
MODERATE SOUTHEASTERLY WINDS AND LOW TO MODERATE SEAS ARE FORECAST
TUESDAY AND WEDNESDAY. WINDS WILL BECOME STRONGER THURSDAY AND
FRIDAY WITH AFTERNOON WIND SPEEDS ON THE LAGUNA MADRE AT OR A LITTLE
ABOVE SMALL CRAFT EXERCISE CAUTION CONDITIONS. SEAS SHOULD REMAIN
MODERATE.

&&

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

$$

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

54/63





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