Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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000
FXUS64 KHGX 101456
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
956 AM CDT THU APR 10 2014

.DISCUSSION...
WEATHER STORY FOR TODAY WILL BE THE MODERATE TO STRONG SOUTH WINDS DUE
TO A STRENGTHENING SURFACE PRESSURE GRADIENT. UPDATE THE WIND GRIDS
SEVERAL KNOTS...AND THAT IS GIVING MUCH OF THE AREA (ESPECIALLY WEST
OF INTERSTATE 45) SUSTAINED SPEEDS OF 15 TO 20 MPH FOR LATE THIS MORNING
AND ON THROUGH THIS AFTERNOON. OF COURSE...THERE WILL BE SOME HIGHER
GUSTS TOO. LOW LEVEL MOISTURE BEGINS BUILDING TONIGHT...SO EXPECT TO
SEE INCREASING CLOUDS ACROSS THE AREA GENERALLY STARTING AFTER MIDNIGHT
TONIGHT.

THE REST OF THE FORECAST PACKAGE WAS MOSTLY UNTOUCHED. UNDER JUST
A LITTLE BIT OF HIGH CLOUDS...EXPECT THIS AFTERNOON`S TEMPERATURES
TO WARM TO AROUND 80 INLAND AND IN THE MID 70S AT THE COAST.  42
&&

.PREV DISCUSSION... /ISSUED 650 AM CDT THU APR 10 2014/

DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION.

AVIATION...
START THE DAY WITH VFR CIGS AND WINDS BECOMING QUITE GUSTY MAINLY
BY AFTERNOON. WINDS DECREASE TO AROUND 10KTS FOR MOST AREAS
OVERNIGHT. MODELS BRING IN SOME TYPE OF MVFR DECK FOR AREA
TERMINALS STARTING AROUND 07-08Z FRI MORNING. NAM SEEMS TOO
AGGRESSIVE WITH LOW MVFR OR IFR IN SOME CASES. GFS LIKES MVFR CIGS
FOR NOW SO WILL STICK WITH THAT TREND IN THE EXTENDED PART OF TAF.

39

PREV DISCUSSION... /ISSUED 504 AM CDT THU APR 10 2014/

DISCUSSION...
A PROGRESSIVE PATTERN WILL PERSIST OVER THE AREA THROUGH THE
WEEKEND AND INTO THE FIRST HALF OF NEXT WEEK. THE GFS AND ECMWF
BOTH FORECAST AN UPPER LOW OVER CENTRAL AND SOUTHERN CA BY FRIDAY
NIGHT. THE MODELS SHEAR OUT THE LOW AND BY SUNDAY MORNING HAVE A
SHORTWAVE TROUGH MOVING ACROSS TEXAS. A WEAK UPPER RIDGE WILL
BUILD OVER SE TX ON TUESDAY BEFORE ANOTHER WEAK UPPER TROUGH MOVES
ACROSS THE STATE LATE WEDNESDAY.

FOR TODAY AND FRIDAY THE MAIN WEATHER IMPACTS WILL BE THE WIND AND
TEMPERATURE FORECASTS. BECAUSE OF THE INCREASING PRESSURE GRADIENT
AND WARM AIR ADVECTION...THE MODELS LOOK REASONABLE IN FORECASTING
NOT MUCH OF A DROP OFF IN WIND SPEEDS TONIGHT AND FRIDAY NIGHT.
GENERALLY SHOULD SEE WIND SPEEDS RANGING FROM 10 TO 15 MPH. THE
GUIDANCE GENERALLY AGREED WITH THE MODEL FORECAST SOUNDINGS IN
WARMING DAYTIME TEMPERATURES TO AROUND 80 OVER THE INLAND AREAS.
THERE WILL ALSO BE A SLOW INCREASE IN THE NIGHTTIME TEMPERATURES
INTO THE MID TO UPPER 60S THROUGH THE WEEKEND.

THE GFS BUFR MODEL SOUNDING FORECASTS KEEP THE CAP IN PLACE
THROUGH SUNDAY MORNING. THE MAIN IMPACT OF THE SHORTWAVE WAS SHOWN
TO BE MORE OVER CENTRAL AND NORTH TEXAS SUNDAY AFTERNOON THROUGH
MONDAY MORNING...BUT MAY CLIP THE NORTHERN COUNTIES. THIS FITS
NICELY WITH THE MODEL SOUNDINGS ERODING THE CAP OVER THE NORTHERN
COUNTIES MORE THAN OVER THE SOUTH. TWEAKED THE CURRENT FORECAST SO
THAT THERE WERE ISOLATED POPS SOUTH OF INTERSTATE 10 SUNDAY
MORNING. FELT THAT SCATTERED POPS WERE GOOD FOR SUNDAY NIGHT AND
MONDAY MORNING.

THERE IS A SLIGHT RISK FOR ISOLATED STRONG OR SEVERE STORMS SUNDAY
AFTERNOON AND EVENING GENERALLY ALONG AND NORTH OF A LINE FROM
COLLEGE STATION TO LIVINGSTON. GFS BUFR SOUNDINGS FOR KCLL AND
KLFK FORECAST CAPE VALUES 2400 TO 3000 AND HELICITY VALUES FROM
300 TO 375. THE SOUTHERN JET STREAM APPROACHES WITH THE AREA NEAR
THE LEFT FRONT EXIT REGION OF THE JET. THE AFOREMENTIONED
SHORTWAVE PASSES TO THE NORTH BUT THERE IS BETTER VORTICITY
ADVECTION OVER THE NORTHERN COUNTIES.

BOTH MODELS PUSH THE FRONT THROUGH EARLY MONDAY MORNING. COOLER
AND DRIER CONDITIONS WILL FOLLOW THE FRONT THROUGH WEDNESDAY.

40

MARINE...
SOUTHERLY WINDS SHOULD INCREASE ACROSS THE UPPER TX COASTAL WATERS
TODAY AND TONIGHT AS LOW PRESSURE MOVES ACROSS THE PLAINS. CAUTION
FLAGS MAY BE NEEDED TONIGHT FOR OFFSHORE WATERS. BREEZY SOUTHERLY
WINDS WILL CONTINUE THROUGH THE WEEKEND SUPPORTING MAINLY MODERATE
SEAS. THE 00Z THUR GFS AND WED 12Z ECMWF ARE STILL IN AGREEMENT
WITH THE NEXT COLD FRONT PUSHING OFF THE COAST MONDAY MORNING. GFS
IS A TOUCH FASTER THAN THE 00Z THUR ECMWF. FORECAST FOR THE
EXTENDED FORECAST WILL BE A BLEND OF THE 00Z GFS AND 12Z WED
ECMWF. REGARDLESS EXPECT SCA CONDITIONS BEHIND THE FRONT LATE
MONDAY AS WINDS INCREASE FROM THE NORTH.

39

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      80  61  80  65  80 /   0   0   0  10  10
HOUSTON (IAH)              80  60  80  63  80 /   0   0   0  10  10
GALVESTON (GLS)            75  66  75  67  76 /   0   0   0  10  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE TONIGHT FOR THE
     FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
     FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
     NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
     20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
     WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.

&&

$$

DISCUSSION...42
AVIATION/MARINE...23



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