Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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000
FXUS64 KHGX 211758
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1158 AM CST FRI NOV 21 2014


.AVIATION...
MESSY CONDITIONS THIS MORNING ACROSS THE REGION WITH IFR
CONDITIONS GENERALLY HOU-11R NORTHWARD (POSSIBLY DIFFUSE SOUTHERN
EXTENT OF THE WARM FRONT) AND MVFR TO VFR SOUTH OF THE LINE.
SHOWERS LIFTING NORTHEAST THROUGH THE REGION THIS MORNING AND
SHOULD GRADUALLY TAPER OFF THOUGH ISOLATED SHOWERS WILL STILL FORM
BUT PROBABLY NOT THE LARGE CLUSTERS/SWATHS AS THEY DID THIS
MORNING.

OVERNIGHT CIGS LOWER AND WIDESPREAD MVFR TO IFR CONDITIONS
PREVAIL. SHOWERS SHOULD FORM OVER THE GULF AND MOVE NORTH TOWARD
MORNING AS LLJ INTENSIFIES TO THE SW AND W. (LIFR POSSIBLE AT
CLL/UTS) UPPER SPEED MAX AT 12Z MOVES NORTHEAST TOWARD THE AREA
AND SHOULD ADD TO THE LIFT IN THE MORNING SO IN GENERAL WILL BE
CARRYING VCSH FOR ALL BUT THE NORTHEAST WITH THUNDERSTORM THREAT
INCREASING FROM SOUTH TO NORTH LATE IN THE MORNING. BIG IMPACTS TO
AVIATION TRAVERSING AND OPERATING IN THE AREA BETWEEN 21Z SAT AND
06Z SUN AS STRONG/SEVERE STORMS TRACK EAST THROUGH THE REGION.

&&

.MARINE...
HAVE EXTENDED THE SCA THROUGH EARLY SUNDAY MORNING FOR THE 20-60NM
WATERS AND SCEC FOR THE NEARSHORE GULF WATERS. WINDS AND SEAS
INCREASING AND SEAS ARE 6-7 FEET AT 42019 AT 17Z. FETCH LENGTHENS
TONIGHT AND GRADIENT PERSISTS SO 8-9 FT SEAS POSSIBLE WELL
OFFSHORE AND SHOULD BUILD TO 5-6 FEET NEARSHORE. LIGHT FOG
POSSIBLE WITH THE SE TRAJECTORIES AND DEWPOINTS PROGGED TO
INCREASE TO MID-UPPER 60S TOWARD MORNING ABOVE THE COOLER SHELF
WATERS.
45

&&

.PREV DISCUSSION... /ISSUED 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


&&

.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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