FXUS64 KHGX 270226
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
826 PM CST THU NOV 26 2009

.DISCUSSION...
SURFACE HIGH PRESSURE IS LOCATED OVER EAST TEXAS. A LARGE SWATH OF
CIRRUS CLOUDS CONTINUES TO SPREAD OVER THE STATE. IT APPEARS THAT
THE CIRRUS WILL BE THICK ENOUGH TO MODERATE MIN TEMPS. HAVE RAISED
MINS A FEW DEGREES OVER THE CENTRAL AND SOUTH ZONES. HAVE ALSO
TWEAKED SKY GRIDS TO MATCH CURRENT TRENDS. STILL LOOKS LIKE A
DOUBLE SHOT OF RAIN EARLY NEXT WEEK. THE FIRST EVENT ON MONDAY
WILL DEVELOP AS A SURFACE COLD FRONT CROSSES THE AREA AND THE
SECOND EVENT ON TUESDAY AS AN UPPER LOW CROSSES EAST TEXAS AND
INTERACTS WITH FAVORABLE JET DYNAMICS. NO CHANGES PAST THE FIRST
PERIOD. 43

&&

.PREV DISCUSSION... /ISSUED 527 PM CST THU NOV 26 2009/ 

DISCUSSION...
SEE AVIATION DISCUSSION.

AVIATION...
HIGH PRESSURE WILL BRING VFR CONDITIONS THROUGH THE PERIOD.
SOUTHEASTERLY WINDS ARE EXPECTED TO DEVELOP ON FRIDAY AS THE HIGH 
PRESSURE DRIFTS OFF THE COAST.

40

PREV DISCUSSION... /ISSUED 329 PM CST THU NOV 26 2009/ 

DISCUSSION...
VERY LITTLE IN THE WAY OF CHANGES TO PREVIOUS
FORECAST. RIDGE OVER SETX HAS MADE FOR A CHAMBER OF COMMERCE
THANKSGIVING. LIGHT NORTHERLY FLOW WITH TEMPERATURES IN THE 60S
WILL COME TO AN END AS WINDS RELAX AND TEMPERATURES DROP QUICKLY
AFTER SUNSET. CIRRUS SPREADING OUT OVER TX AND THIS WILL CONTINUE
TO INCREASE ACROSS SETX AS UPPER CIRC OVER BAJA MOVES EAST AND
ACROSS THE REGION FRIDAY NIGHT/EARLY SATURDAY MORNING. AS THE
CIRCULATION CROSSES THE AREA ANTICIPATING MOSTLY CLOUDY TO CLOUDY
SKIES. LL FLOW BECOMING ONSHORE FRIDAY NIGHT/SATURDAY AND PICKING
UP. AREA MOISTENS UP SATURDAY AND WITH RELISH ON SUNDAY AS LL FLOW
TIGHTENS UP. THE UPPER LOW NEARING THE OREGON COAST THIS AFTERNOON
WILL DROP SOUTHEAST AND BECOME OUR WEATHER MAKER FOR SUNDAY
AFTERNOON- TUESDAY. IMPRESSIVE COLD FRONT SWEEPS INTO THE AREA
SUNDAY NIGHT AND REACHES THE COAST MONDAY AROUND SUNRISE AND THEN
OUT OFFSHORE BEFORE NOON. WIDESPREAD RA/SHRA SHOULD DEVELOP AND
PERSIST AS MOIST SW FLOW OVERRUNS THE FRONTAL BOUNDARY. WIDESPREAD
RAINS OF MORE THAN ONE HALF INCH LOOKING LIKELY AND MAY HAVE SOME
THREAT OF HEAVY RAINFALL THOUGH CONFIDENCE ISN'T HIGH ENOUGH YET
TO MENTION IN ZFP. THE LEAD SHORT WAVE SWINGS EAST AND IN ITS WAKE
BRING A BRIEF BREAK TO THE RAINS MONDAY AFTERNOON/EVENING BEFORE
THE UPPER LOW MOVES EAST AND GETS CLOSER TO SETX. THIS SLOW MOVING
UPPER LOW WILL BRING BACK HIGH POPS WITH MORE RAIN AND POSSIBLY
TSRA IF INSTABILITY PANS OUT THAT MODELS ARE CURRENTLY PROGGING.
ONLY SIGNIFICANT CHANGES TO PREVIOUS PACKAGE WAS TO CONTINUE TO
NUDGE UP POPS FOR THIS EVENT AS CONFIDENCE GROWS AND ALSO TO LOWER
AFTERNOON TEMPERATURES FOR TUESDAY AS WIDESPREAD RAIN AND CAA WILL
LIKELY MEAN A FLATLINE FOR TEMPS ON TUESDAY...HAVE UNDERCUT MEX
GUIDANCE BY 3-6 DEGREES ON TUESDAY AND WANTED TO GO BIGGER BUT IF
THE RAINS DON'T MATERIALIZE AS CURRENT MODELS PROGGING THEN TEMPS
WILL BE WARMER. IMPRESSIVE DIFFLUENCE ON TUESDAY COULD WELL HELP
TO FUEL HEAVIER RAINS AGAIN. OVERNIGHT CLOUD COVER WELL INTO THE
MIDDLE OF NEXT WEEK SHOULD RULE OUT ANY FREEZING TEMPERATURES
THOUGH UPPER 30S TO AROUND 40 WILL OCCUR.

45

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      39  67  49  73  60 /   0   0  10  10  20 
HOUSTON (IAH)              40  67  50  72  61 /   0   0  10  10  20 
GALVESTON (GLS)            51  66  58  71  66 /   0   0  10  10  20 

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 PM CST THIS EVENING 
     FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE 
     MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH 
     ISLAND TO FREEPORT 20 TO 60 NM.

&&

$$

DISCUSSION...43