Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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000
FXUS64 KHGX 230003
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
603 PM CST SAT NOV 22 2014

.DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.

&&

.AVIATION...
WATER VAPOR IMAGERY SHOWS LEAD SHORT WAVE AHEAD OF MAIN UPPER LOW
OVER BIG BEND/RIO GRANDE VALLEY MOVING ACROSS SE TX. SFC ANALYSIS
HAS WARM FRONT DIAGONAL FROM NORTH OF AUS TO KCLL DOWN TO THE
GOLDEN TRIANGLE. SECOND ROUND OF CONVECTION BASED ON HRRR/RAP
TRENDS IS EXPECTED TO PUSH ACROSS THE AREA AROUND 06Z. ALREADY
SEEING THE START OF A SQUALL LINE DEVELOPING UNDER UPPER LOW OVER
WEST HILL COUNTRY.

KCLL/KUTS/KCXO...FAIRLY STOUT CLUSTER OF TSRA W OF KUTS AND E OF
KCLL WILL MOVE THROUGH THE AREA OVER THE NEXT HR OR TWO. MAIN
IMPACT WILL BE FOR KUTS WITH CIGS DROPPING TO IFR WITH GUSTY
WINDS. THINK SQUALL LINE OF STORMS WILL REACH THESE TERMINALS
03-04Z AND MOVING OUT PAST 06-07Z. CIGS AND OVERALL AVIATION
CONDITIONS SHOULD IMPROVE AFTER THAT WITH SW WINDS TOMORROW.

KIAH/KHOU/KSGR...CURRENT AREA OF SHRA AND ISO TSRA WILL BE MOVING
THROUGH HOUSTON TERMINALS OVER THE NEXT HR. STORMS MAY DROP CIGS
TO IFR WITH SOME LIMITED VSBY AND GUSTY WINDS. SHOULD HAVE A BREAK
FOR A FEW HRS AHEAD OF NEXT ROUND OF STORMS WHICH SHOULD BE A
DEVELOPING SQUALL LINE. LOOK FOR STORMS TO REACH HOUSTON TERMINALS
05-07Z SO ADDED TEMPO FOR +TSRA AND GUSTY WINDS. ONCE LINE MOVES
THROUGH EXPECT CIGS TO IMPROVE ALONG WITH OVERALL AVIATION WEATHER
CONDITIONS. VFR TOMORROW WITH SW WINDS.

KLBX/KGLS...LINE OF SHRA CURRENTLY MOVING THROUGH TERMINALS SHOULD
BE SHORT LIVED AND MOVE OUT WITHIN THE NEXT HR. MAIN CONCERN WILL
BE LATER TONIGHT FROM 05-08Z WHEN A LINE OF STORMS MOVES THROUGH
THE AREA. MENTION +TSRA AND GUSTY WINDS FOR POSSIBLE SQUALL LINE
THAT WILL PUSH THROUGH. CIGS AND OVERALL CONDITIONS WILL IMPROVE
AFTER 08-09Z. VFR TOMORROW WITH SW WINDS.

39

&&

.PREV DISCUSSION... /ISSUED 412 PM CST SAT NOV 22 2014/

DISCUSSION...
COMPLICATED FORECAST UNFOLDING TODAY MAY LEAVE PEOPLE WITH
QUESTIONS ABOUT WHERE THE STORMS ARE...AND WHEN THEY WILL ACTUALLY
HAPPEN. SEVERAL FACTORS SEEM TO HAVE COME INTO PLAY THAT HAVE
HELPED LIMIT OR WEAKEN MORE WIDESPREAD ACTIVITY IN SOUTHEAST
TEXAS SO FAR TODAY. THE EDGE OF BETTER WAA AND LOW-LEVEL MOISTURE
THIS MORNING STRADDLED A LINE FROM MATAGORDA BAY NORTH TOWARDS
WACO...LEAVING ANY ACTIVITY THAT ATTEMPTED TO STRAY FROM THIS
REGION EARLIER IN THE DAY LARGELY UNSUPPORTED. PERSISTENT CLOUD
COVER HAS ALSO DONE A GOOD JOB OF LIMITING INSTABILITY...A 16Z
SOUNDING FROM TEXAS A&M AND A 19Z SOUNDING FROM THE UNIVERSITY OF
HOUSTON BOTH REVEALED A FAIRLY STABLE AIRMASS IN PLACE ACROSS THE
AREA. A FEW PEEKS OF SUNSHINE TODAY HAVE ALLOWED SOME
DESTABILIZATION OVER THE SOUTHWESTERN COUNTIES AND THE BULK OF
THIS AFTERNOON/S ACTIVITY PRESENTLY RESIDES WEST OF INTERSTATE 45.

REGIONAL RADAR MOSAIC AS OF 3 PM SHOWS A LINE OF THUNDERSTORMS
BEGINNING TO CONGEAL INTO A LINE OVER WESTERN NORTH TEXAS...WITH
ADDITIONAL DISCRETE STORMS DEVELOPING WEST OF THE RIO GRANDE. HIGH
RESOLUTION MODELS INDICATE THAT THESE FEATURES WILL PUSH EAST AND
MAY MERGE AS A STRONG UPPER JET ALSO SHOVES THE SHORTWAVE TROUGH
CURRENTLY LOCATED OVER SOUTHWEST TEXAS/THE BIG BEND TO THE EAST.
PRESENT THINKING ON THE EVOLUTION OF STORMS FOR THIS EVENING AND
THE OVERNIGHT HOURS IS FOR ONE...POTENTIALLY TWO IF THE LINE IS
BROKEN...LINEAR STORM CLUSTERS TO MOVE ACROSS SOUTHEAST TEXAS AND
THE COASTAL WATERS. ANTICIPATE THE TIMING FOR THESE STORMS TO
ENTER ALONG A CALDWELL/ COLUMBUS/ PALACIOS LINE SOMEWHERE AROUND
10 PM TO MIDNIGHT... AND PUSH EAST TOWARDS THE HOUSTON METRO BY 3
AM. ANTICIPATE ALL RAIN TO EXIT THE AREA BETWEEN 6-8 AM SUNDAY.

LOW-LEVEL SHEAR WILL INCREASE ALONG THE COAST /0-1 KM SHEAR
NEAR 30 KTS/ LATE TONIGHT AS A 40-45 KT LOW LEVEL JET IS SHUNTED
EAST AHEAD OF THE APPROACHING SHORTWAVE TROUGH... KEEPING THE
CONCERN FOR AN EMBEDDED TORNADO OR TWO MAINLY ALONG THE COAST AS
TONIGHT/S LINE PASSES. OTHERWISE...THE MAIN THREATS FOR TONIGHT/S
STORMS CENTERS AROUND HAIL...GUSTY WINDS...AND HEAVY RAIN WITH
NAEFS ENSEMBLES POINTING TO PWATS AROUND 1.5 INCHES CLOSE TO TWO
STANDARD DEVIATIONS ABOVE NORMAL.

FOR SUNDAY... DRY CONDITIONS AND WESTERLY WINDS IN PLACE WILL
ALLOW TEMPERATURES TO APPROACH THE 80 DEGREE MARK BEFORE A COLD
FRONT LATE SUNDAY NIGHT INTO MONDAY DROPS TEMPERATURES BACK NEAR
NORMAL ON MONDAY WITH HIGH TEMPERATURES ONLY REACHING THE 60S. A
RATHER BENIGN WEATHER PATTERN SETS UP FOR THE REMAINDER OF NEXT
WEEK WITH RIDGING OVER THE WESTERN CONUS AND A TROUGH OVER THE
EAST. A SURFACE HIGH SETTLING INTO THE GULF BEHIND THE FRONT AT
THE BEGINNING OF THE WEEK WILL LIMIT MOISTURE RETURN BACK INTO
THE AREA...KEEPING THANKSGIVING WEEK PLEASANT AND DRY.

HUFFMAN

MARINE...

WILL CARRY CAUTION FLAGS FOR THE BAYS AND NEARSHORE WATERS AND SMALL
CRAFT ADVISORIES FOR THE OFFSHORE WATERS THROUGH SUNDAY. STRONG STORM
SYSTEM MOVING ACROSS THE AREA TONIGHT WILL BRING SHOWERS AND THUNDER-
STORMS TO THE AREA...WITH SOME POSSIBLE STRONG OR SEVERE WITH MAINLY
STRONG WINDS AS THE PRIMARY SEVERE WEATHER THREAT. STORMS WILL MOVE
TO THE EAST OF THE AREA BEFORE SUNRISE SUNDAY MORNING...AND THIS COULD
RESULT IN A SLIGHTLY WEAKER PRESSURE GRADIENT WHICH COULD ALLOW FOR
SOME OF THE FLAGS TO BE LOWERED OR EVEN DROPPED (ESPECIALLY FOR THE
BAYS AND NEARSHORE WATERS). COLD FRONT WILL MOVE THROUGH THE WATERS
SUNDAY NIGHT. MODERATE/STRONG OFFSHORE WINDS IN THE WAKE OF THE FRONT
WILL PREVAIL THROUGH TUESDAY...THEN WILL DECREASE AND BECOME MORE WEST
TO SOUTHWEST ON WEDNESDAY. THANKSGIVING DAY LOOKS QUIET WITH LIGHT TO
POSSIBLE MODERATE SOUTH TO SOUTHWEST WINDS WITH 1 TO 2 FOOT SEAS NEAR-
SHORE AND 2 TO 3 FOOT SEAS OFFSHORE. 42

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      57  78  45  64  40 /  90  10   0   0   0
HOUSTON (IAH)              59  80  49  65  41 /  90  10   0   0   0
GALVESTON (GLS)            65  76  56  64  50 /  90  10   0   0   0

&&

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

     SMALL CRAFT ADVISORY UNTIL 6 PM CST SUNDAY 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...41
AVIATION/MARINE...39



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