Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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000
FXUS64 KHGX 211602
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1002 AM CST FRI NOV 21 2014

.DISCUSSION...
LIGHT RAIN WILL CONTINUE THROUGH THE DAY TODAY AS WARM AIR
ADVECTION CONTINUES AHEAD OF THE APPROACHING STORM SYSTEM. CURRENT
FORECAST IS IN GOOD SHAPE AND ONLY ADJUSTMENTS WERE TO BRING
DEWPOINTS UP BY A DEGREE OR TWO ACROSS OUR WESTERN COUNTIES TO
MATCH CURRENT TRENDS. 38

&&

.PREV DISCUSSION... /ISSUED 408 AM CST FRI NOV 21 2014/

DISCUSSION...
HAVE SOME ONGOING WAA SHRA AS LLVL JET TAPS INTO DEEPER MOISTURE
EXTENDING SWD ACROSS THE WESTERN GULF. THIS ACTIVITY WILL PROBABLY
CONTINUE THROUGHOUT THE DAY & WE MAY EVEN SEE AN ISOLATED TSTM OR
TWO - BUT FOR THE MOST PART JUST GENERALLY LIGHT NUISANCE PRECIP.
PRECIP SHOULD TRANSITION BACK INTO CNTL TX LATER IN THE DAY AND
TONIGHT AS LLJ SHIFTS THAT WAY.

NEXT STORM SYSTEM STILL ON TARGET TO MOVE THRU SE TX ON SAT AND
SAT EVNG. SATELLITE PIX CURRENTLY SHOW THIS SYSTEM OVER SOCAL AND
SHOULD CONTINUE DIGGING SEWD ACROSS NCNTL MEXICO AND INTO CNTL TX
ON SAT. AS IT MOVES INTO SE TX SAT EVNG & NIGHT MODELS SHOW IT
TAKING A NEGATIVE TILT AS IT THEN HEADS NE INTO LA/AR. SOME OF THE
PREVIOUS MODEL RUNS SUGGESTED THIS TILT MIGHT OCCUR A BIT SOONER
AND A BIT FURTHER WEST. BUT...OVERALL DYNAMICS WITH THIS SYSTEM
STILL REMAIN QUITE POTENT WITH HIGH FAIRLY HIGH SHEAR VALUES AND
EXCELLENT DIFFLUENCE ALOFT. CAPE VALUES ARE JUST MODEST...MAINLY
500-1200 J/KG...BUT FALL WITHIN CLIMO RANGE OF PAST WINTERTIME
SEVERE WX EPISODES HERE. ANOTHER POSITIVE IN RESPECT TO SVR WX
POTENTIAL IS THIS SYSTEM WILL BE MOVING INTO THE REGION NEAR OR
SLIGHTLY AFTER PEAK HEATING. EXACTLY HOW THIS EVENT EVOLVES IS
STILL SOMEWHAT UNCERTAIN, BUT WOULD GENERALLY EXPECT SOME SCT
ACTIVITY TO DEVELOP TO OUR WEST SAT MORNING AND ACROSS OUR W/SW
PARTS DURING THE EARLY AFTN. ANTICIPATE MUCH OF THIS PRECIP TO
EVENTUALLY CONSOLIDATE INTO AN MCS/SQUALL LINE FAIRLY CLOSE, OR
IN, SE TX BEFORE MOVING TOWARD A MATAGORDA-LIBERTY-TEXARKANA LINE
TOWARD MIDNIGHT. PRIMARY SEVERE WX THREATS WILL BE TORNADOES
(MOSTLY IN DISCREET SCT CELLS OUT IN FRONT) AND DAMAGING WINDS
(BOWING SEGMENTS WITHIN TSTMS/SQUALL LINE ITSELF). HAIL WOULD BE
SECONDARY THREAT. WILL LIKELY SEE SOME HEAVY DOWNPOURS AS WELL,
BUT W/ FAST STORM MOTION OVERALL FLOOD THREAT SHOULD BE LIMITED TO
THE USUAL METRO STREETS THAT CAN`T HANDLE THE FAST HEAVY RATES.

THE STORM SYSTEM SHOULD BE OUT OF THE AREA BY SUNDAY MORNING AND
DRY SW/W FLOW IN ITS WAKE SHOULD ALLOW FOR A GOOD WARM UP. COLD
FRONT PUSHES THROUGH LATE SUNDAY NIGHT FOLLOWED BY A REINFORCING
FRONT TUESDAY. THESE FRONTS SHOULD BE MOISTURE STARVED AND BOTH
PUSH THRU RAIN-FREE. TURKEY DAY LOOKS DRY AS WELL WITH LOWS IN
40S & HIGHS 65-70. 47

MARINE...
WITH STRONG ONSHORE WINDS CONTINUING OVER THE OFFSHORE WATERS WILL
BE KEEPING THE SMALL CRAFT ADVISORY IN PLACE THROUGH THIS AFTN. AS
THE GRADIENT TIGHTENS TODAY IN RESPONSE TO THE DEEPENING UPPER LOW
OUT WEST...INCREASED WIND SPEEDS ARE LIKELY FOR THE NEARSHORE WAT-
ERS AS WELL. SCA SHOULD BE EXPANDED/EXTENDED AS THIS STRONG SYSTEM
APPROACHES. STRONG TO SEVERE THUNDERSTORMS POSSIBLE SAT AFTN/NIGHT
WITH WINDS BECOMING SW IN THE WAKE OF THIS SYSTEM ON SUN. THE NEXT
COLD FRONT IS CURRENTLY FCST TO MOVE OFFSHORE EARLY MON MORNING. 41

AVIATION...
SOMEWHAT MESSY TAF FCST EXPECTED TO CONTINUE WITH THE 12Z PACKAGE
GIVEN INCREASED MOISTURE/WEAK DISTURBANCE FROM THE WEST. WILL NOT
CHANGE TOO MUCH WITH THE VCSH WORDING THRU THE REST OF THIS MORN-
ING BUT WE COULD SEE SOME IMPROVEMENT WITH CIGS BY THIS AFTN. MAY
HAVE TO INCLUDE THE MENTION OF REDUCED VISBY (SEA FOG) FOR GLS AT
(OR AFTER) 22/06Z. 41

&&

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL)      74  63  73  58  78 /  60  30  90  80   0
HOUSTON (IAH)              75  63  76  62  79 /  50  20  80  90   0
GALVESTON (GLS)            73  66  74  67  78 /  30  20  70  90   0

&&

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

     SMALL CRAFT ADVISORY UNTIL 4 AM 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...38
AVIATION/MARINE...45


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