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000
FXUS64 KHGX 281220
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
720 AM CDT MON JUL 28 2014

.UPDATE...
UPDATE FOR DENSE FOG.

&&

.DISCUSSION...
VISIBILITY WILL BOUNCE AROUND 1 MILE TO 1/4 MILE IN MOST AREAS SW
OF HOUSTON DUE TO FOG SO ISSED DENSE FOG ADVSIORY FOR NEXT COUPLE
OF HOURS. UPDATED FORECAST HAS BEEN SENT.

39

&&

.PREV DISCUSSION... /ISSUED 642 AM CDT MON JUL 28 2014/

DISCUSSION...
SEE AVIATION FOR 12Z TAF ISSUANCE

AVIATION...
CORRIDOR OF IFR CIGS EXTENDING FROM NEAR SAN ANTONIO TO LA GRANGE
IS SPREADING EASTWARD AND MAY PRODUCE SOME LOW CLOUDS AT CLL EARLY
THIS MORNING. ELSEWHERE PATCHY FOG ARE DEVELOPING ACROSS OUR
SOUTHWESTERN COUNTIES WITH VSBYS VARIABLE AT SGR AND LBX. ALL OF
THIS SHOULD COME TO AN END BY MID MORNING WITH VFR CONDITIONS
EXPECTED THROUGH THE REMAINDER OF THE DAY. WINDS WILL BE VARIABLE
AND LIGHT TODAY AS A FRONTAL BOUNDARY ACROSS NORTH TEXAS SAGS
SOUTHWARD. SOME SHOWERS ARE POSSIBLE THIS EVENING FOR CLL/UTS
DEPENDING UPON HOW FAR SOUTH THE BOUNDARY CAN MAKE IT. 38

PREV DISCUSSION... /ISSUED 420 AM CDT MON JUL 28 2014/

DISCUSSION...
SFC ANALYSIS HAS COLD FRONTAL BOUNDARY STRETCHING FROM THE MID-
SOUTH ACROSS S PLAINS INTO TX PANHANDLE WHERE MCS HAS DEVELOPED.
GOES SOUNDER PRECIP WATER SHOWS A SWATH OF DEEP MOISTURE WITH PW
VALUES OF 2 INCHES MAINLY ACROSS THE ARKLATEX AND RED RIVER
REGION OR JUST SOUTH OF THE FRONTAL BOUNDARY. THIS IS ALSO WHERE
OTHER SCT STORMS HAVE DEVELOPED ACROSS S OK. UPPER AIR ANALYSIS AT
500MB FROM 00Z SOUNDINGS SHOW A BROAD UPPER LEVEL RIDGE FROM THE
GREAT BASIN TO N TX INTO THE N GULF. HEIGHTS ARE HIGHER THAN
PREVIOUSLY PROGGED AND SUGGEST A BROADER AREA OF SUBSIDENCE. THAT
SAID DEEP CONVECTION IS DEVELOPING UNDER THE RIDGE DUE TO SFC
CONVERGENCE WITH THE FRONTAL BOUNDARY AND A WEAK TROUGH AXIS
MOVING THROUGH THE MIDWEST BACK TO THE S PLAINS. THINK RAIN
CHANCES TODAY AND TONIGHT MAY BE MORE LIMITED THAN FORECAST. THE
RIDGE IS STRONGER SO IT WILL TAKE STRONG LOW LEVEL CONVERGENCE
WITH THE FRONTAL BOUNDARY FOR CONVECTION TO DEVELOP. THEN AGAIN
IT IS HARD TO TELL HOW FAR SOUTH THE FRONTAL BOUNDARY WILL SAG
INTO TX AS IT WILL MORE THAN LIKELY BECOME STATIONARY INTO TUE.
MODELS ARE NOT INDICATING MUCH QPF FROM CONVECTION SO COULD JUST
LEAVE 20 POPS FOR TONIGHT INTO TUE. THINK IT WILL BE BETTER TO
JUST LEAVE THE 30 POPS IN THE FORECAST GIVEN THE CHANCE OF THE
FRONT PUSHING AS FAR SOUTH AS THE MODELS SUGGEST. THIS WILL MAINLY
JUST AFFECT THE NORTHERN MOST AREAS OF THE FORECAST AREA.

TUE/WED THINK MAINLY 20/30 POPS WILL BE ON TRACK AGAIN AND COULD
BE A BIT HIGH. THE UPPER RIDGE REALLY DOES NOT WEAKEN UNTIL WED
SO COULD EXPECT HOT CONDITIONS TO CONTINUE THE NEXT COUPLE OF
DAYS. THE FRONTAL BOUNDARY SLOWLY DISSIPATES TUE/WED BUT STILL
COULD BE THE FOCUS FOR THUNDERSTORM ACTIVITY. OUTFLOW FROM STORM
COMPLEXES COULD EASILY MAINTAIN SOME FRONTAL CONTINUITY FOR THE
MIDDLE OF THE WEEK.

SYNOPTIC MODELS SEEM TO BE TRENDING TOWARDS A MORE WET END OF THE
WEEK. BOTH THE GFS/ECMWF BRING A SHORT WAVE TROUGH ACROSS THE
PLAINS THUR INTO FRI. THIS SEEMS TO FORCE QUITE A BIT OF PRECIP
OVER OK AND N TX. THIS INITIAL CONVECTIVELY INDUCED PRECIP
DEVELOPS WELL NORTH OF THE AREA BUT LOOKS LIKE ANOTHER MCS COULD
DEVELOP OVER THE E HALF OF TX FRI MORNING AS THE FRONTAL BOUNDARY
FINALLY PUSHES FARTHER INTO THE AREA. WILL KEEP 30 POPS IN THE
FORECAST BUT LACK FORECAST CONFIDENCE TO GO HIGHER WITH RAIN
CHANCES SINCE MODELS HAVE NOT BEEN PERFORMING WELL WITH TRENDS IN
THE RIDGE. PLUS QUITE A BIT OF THE FORECAST WILL HINGE ON
MESOSCALE DETAILS WHICH CANNOT BE DETERMINED AT THIS TIME. THAT
SAID THE GFS AND ECMWF ARE MORE ROBUST WITH RAIN CHANCES HEADED
INTO THE END OF THE WEEK WITH THE FRONTAL BOUNDARY STALLED ACROSS
THE AREA. THE 500 MB RIDGE HAS ALSO SUFFICIENTLY WEAKENED TO NEAR
588 DM HEIGHTS WITH NW FLOW ALOFT. OVERALL THINK THAT SINCE THE
MODELS HAVE DONE A POOR JOB WITH THE EVOLUTION OF THE
RIDGE...THERE IS LITTLE CONFIDENCE IN RAIN CHANCES TO THE START OF
THE WEEK BUT LOOK FOR CHANCES TO INCREASE FOR THE END OF THE WEEK.

39

MARINE...
LIGHT TO MODERATE SOUTH TO SOUTHWEST WINDS WILL PERSIST THROUGH THE
FIRST HALF OF THE WEEK. WINDS WILL REMAIN VARIABLE THROUGH THE END
OF THE WEEK AS A FRONTAL BOUNDARY APPROACHES SOUTHEAST TEXAS. THIS
FRONT MAY PUSH OFFSHORE LATE IN THE WEEK OR EARLY NEXT WEEK BRINGING
LIGHT OFFSHORE WINDS. 38

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      97  76  96  76  96 /  20  30  30  20  20
HOUSTON (IAH)              97  76  95  76  95 /  10  30  30  20  20
GALVESTON (GLS)            91  81  91  80  91 /  10  20  30  20  20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR THE FOLLOWING
     ZONES: BRAZORIA...FORT BEND...MATAGORDA...WHARTON.

GM...NONE.
&&

$$

DISCUSSION...39