Tornado Warning 144, NWS Lake Charles, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
935 AM CST TUE NOV 11 2008

.UPDATE...

SURFACE ANALYSIS SHOWS WARM FRONT CURRENTLY BISECTING THE
FORECAST AREA ALONG A LINE FROM FORT POLK TO NEAR MARSH ISLAND.
SFC DEWPOINTS ARE IN THE 50S OVER THE NORTHEASTERN ZONES AND
APPROACHING 70 IN THE SOUTHWEST. RADAR IMAGERY SHOWS SCATTERED
SHOWERS CONTINUING ACROSS THE NORTHWESTERN HALF OF THE AREA WITH A
LINE OF HEAVIER SHOWERS AND THUNDERSTORMS APPROACHING THE CWA FROM
THE NORTHWEST. MADE SEVERAL ADJUSTMENTS TO POP GRIDS FOR TODAY
INTO TOMORROW WITH LIKELY TO CATEGORICAL PRECIP CHANCES OVER MUCH
OF THE WESTERN AND NORTHERN ZONES. SPC HAS SE TX AND W LA IN A
SLIGHT RISK OF SEVERE STORMS FOR TODAY WITH MAIN THREATS BEING
ISOLATED TORNADOES AND WIND DAMAGE. 12Z KLCH SOUNDING HAS
IMPRESSIVE SRH VALUES BUT INSTABILITY IS STILL LACKING. APPEARS
BIGGEST THREAT ATTM IS HEAVY RAINFALL DUE TO THE CONTINUED
REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS TODAY AND TOMORROW.
ALSO MADE SEVERAL ADJUSTMENTS TO WIND GRIDS PRIMARILY ACROSS
MARINE ZONES WHERE WINDS AND SEAS WARRANT A SCA THROUGH TOMORROW.
UPDATED PRODUCTS OUT SHORTLY.

SHAMBURGER

&&

.PREV DISCUSSION... /ISSUED 503 AM CST TUE NOV 11 2008/

SYNOPSIS...THE WARM FRONT FROM THE LOUISIANA COAT TO A SURFACE
LOW IN WESTERN KANSAS HAS BECOME BETTER DEFINED BUT REMAINS SLOW MOVING.
A GOOD MOISTURE SURGE WAS EVIDENT IN THE WARM SECTOR INTO CENTRAL
TEXAS AHEAD OF A PACIFIC COLD FRONT/DRY LINE IN WEST TEXAS. A
POSITIVELY TILTED SHORTWAVE TROF COMING OUT OF SPLIT FLOW IN THE
ROCKIES IS DIGGING INTO NEW MEXICO.

DISCUSSION...WILL FAVOR THE GFS SOLUTION IN THE SHORT TERM WHICH
TRIES TO DEVELOP A COASTAL LOW IN SOUTH TEXAS IN A FAVORABLE
CYCLOGENIC REGION DOWNSTREAM FROM THE SHARP SHORTWAVE TROF TODAY.
THIS WILL AMPLIFY THE MOISTURE OVER EAST TEXAS AND INTO LOUISIANA
LATE TODAY AND TONIGHT. SURFACE CONVERGENCE WILL GIVE FOCUSING TO
THE SHOWERS AND THUNDERSTORMS OVER OUR NORTHERN TIER. ALTHOUGH A
LONG DURATION HEAVY RAINFALL EVENT LOOKS TO BE IN THE CARDS, WILL
FOREGO ANY FLOOD WATCH AS THE SOIL HAS BEEN VERY DRY THIS FALL.
TOTAL RAIN EVENT SHOULD PRODUCE ANYWHERE FROM AROUND AN INCH
ACROSS THE I-10 CORRIDOR TO 4 TO 6 INCHES ACROSS THE LAKES AREA OF
SE TEXAS THROUGH CENTRAL LOUISIANA BEFORE PRECIP TAPERS OFF ON
THURSDAY AS THE UPPER TROF MOVES THROUGH. A SLIGHT RISK FOR SEVERE
THUNDERSTORM EXISTS THROUGH TONIGHT WEST OF LAKE CHARLES AND LEESVILLE.
MAINLY DUE TO AN INCREASED CHANCE OF LARGE HAIL AS UPPER LEVEL
TEMPS FALL NEAR THE UPPER TROF. THERE IS A MARGINAL THREAT FOR
ROTATING TSTMS/TORNADOES DEPENDANT ON ANY CLOUD FREE AREAS
ALLOWING SURFACE HEATING. THERE IS SUFFICIENT SHEAR BELOW 5K FEET.
AM EXPECTING RAIN COOLED AIR TO HOLD TEMPS DOWN THROUGH WEDNESDAY NIGHT.

AVIATION...CIGS HAD STEADILY LOWERED AND REACHED MVFR LEVELS AT
LCH AT TIMES OVER THE LAST SEVERAL HOURS. EXPECT THOSE CIGS TO
CONTINUE BOUNCING BETWEEN MVFR AND VFR TODAY AS A MOIST SOUTHERLY
FETCH CONTINUES. FURTHER WEST...BPT SHOULD GO PREDOMINANT MVFR ON
CIGS DUE TO CLOSER PROXIMITY TO THE LOW LEVEL JET AND THE
ATTENDANT MOIST RIDGE INTO CENTRAL TEXAS. LFT AND ARA OUT TO THE
EAST SHOULD REMAIN VFR IN THE DRIER AIR. AEX WILL HAVE TO DEAL
WITH HEAVY RAIN IN EMBEDDED TSTMS WITH MFR CIGS. UPDATED TAFS AT
AEX WILL LIKELY HAVE TEMPO IFR VIS IN HEAVY RAINS AS CELLS APPEAR UPSTREAM.

MARINE...INHERITED MARGINAL CRITERIA FOR A SMALL CRAFT ADVISORY
AND ALLOW THIS TO EXPIRE AT 10 AM. MAINLY FOR SEAS EXCEEDING 6 FEET.
WILL HAVE A BETTER SHOT OF REACHING SCA CRITERIA LATE TNITE IN
RESPONSE TO A POSSIBLE COASTAL LOW KICKING UP THE SOUTHERLY WINDS
AND BUILDING SEAS AGAIN. VAD WINDS AT 1K FEET SHOW DIMINISHING
WINDS TO 15 KNOTS AND SHOULD BE REPRESENTATIVE OVER THE NEAR SHORE WATERS.

&&

.PRELIMINARY POINT TEMPS/POPS...
KLCH  76  68  70  59  76 /  50  70  80  50  20
KBPT  76  68  67  57  75 /  50  70  80  50  20
KAEX  72  65  64  58  73 /  70  70  80  50  20
KLFT  76  65  72  59  78 /  30  40  80  70  20

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM CST WEDNESDAY FOR THE
     FOLLOWING ZONES: COASTAL WATERS FROM LOWER ATCHAFALAYA
     RIVER TO INTRACOASTAL CITY, LA OUT 20 NM...WATERS FROM
     LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY, LA EXTENDING
     FROM 20 NM TO 60 NM.

     SMALL CRAFT ADVISORY UNTIL 6 PM CST WEDNESDAY FOR THE FOLLOWING
     ZONES: COASTAL WATERS FROM CAMERON, LA TO HIGH ISLAND, TX
     OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO
     CAMERON, LA OUT 20 NM...WATERS FROM CAMERON, LA TO HIGH
     ISLAND, TX EXTENDING FROM 20 NM TO 60 NM...WATERS FROM
     INTRACOASTAL CITY, LA TO CAMERON, LA EXTENDING FROM 20 NM
     TO 60 NM.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAKE CHARLES LA
542 AM CST TUE NOV 11 2008

GMZ430-432-435-450-452-455-470-472-475-LAZ027>033-041>045-051>055-
TXZ180>182-201-215-216-121145-
SABINE LAKE-CALCASIEU LAKE-VERMILION BAY-
COASTAL WATERS FROM CAMERON, LA TO HIGH ISLAND, TX OUT 20 NM-
COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON, LA OUT 20 NM-
COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY,
LA OUT 20 NM-
WATERS FROM CAMERON, LA TO HIGH ISLAND, TX EXTENDING FROM 20 NM
TO 60 NM-
WATERS FROM INTRACOASTAL CITY, LA TO CAMERON, LA EXTENDING FROM
20 NM TO 60 NM-
WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY, LA
EXTENDING FROM 20 NM TO 60 NM-VERNON-RAPIDES-AVOYELLES-BEAUREGARD-
ALLEN-EVANGELINE-ST. LANDRY-CALCASIEU-JEFFERSON DAVIS-ACADIA-
LAFAYETTE-UPPER ST. MARTIN-CAMERON-VERMILION-IBERIA-ST. MARY-
LOWER ST. MARTIN-TYLER-JASPER-NEWTON-HARDIN-JEFFERSON-ORANGE-
542 AM CST TUE NOV 11 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE NORTHWEST
GULF OF MEXICO...CENTRAL LOUISIANA...SOUTH CENTRAL LOUISIANA...
SOUTHWEST LOUISIANA...WEST CENTRAL LOUISIANA AND SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

A SLIGHT RISK FOR SEVERE THUNDERSTORMS WEST OF A LINE FROM LAKE
CHARLES TO LEESVILLE THROUGH TONIGHT. LARGE HAIL IS THE MAIN
CONCERN AS AN UPPER LEVEL TROUGH OVER TEXAS APPROACHES. THERE IS A
MARGINAL THREAT FOR ROTATIN THUNDERSTORMS DEPENDING ON HOW MUCH
DAYTIME HEATING CAN DESTABILIZE THE ATMOSPHERE. ALTHOUGH THERE IS
SUFFICIENT LOW LEVEL SHEAR BELOW 5K FEET, RAIN COOLED AIR SHOULD
KEEP TEMPERATURES BELOW CONVECTIVE LEVELS.

THE MAIN ISSUE TODAY SHOULD BE HEAVY RAINFALL FROM LUFKIN TO LEESVILLE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A SECONDARY LOW LIFTING OUT OF SOUTH TEXAS COASTAL AREA AND INTO
OUR AREA WILL COMBINE WITH THE UPPER LEVEL TROF TO PRODUCE HEAVY
RAINFALL INTO WEDNESDAY NIGHT. SHOWERS SHOULD TAPER OFF ON
THURSDAY AS THE MAIN TROF AXIS MOVES SLOWLY EAST. TOTAL RAINFALL
AMOUNTS SHOULD RANGE FROM AROUND AN INCH ALONG THE I-10 CORRIDOR
TO UPWARDS OF 4 TO 6 INCHES IN THE LAKES AREA OF SOUTHEAST TEXAS
AND CENTRAL LOUISIANA. FLOODING DOES NOT APPEAR TO BE A PROBLEM AS
THE GROUND HAS BEEN VERY DRY SINCE IKE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS EVENING FOR A FEW EMBEDDED
THUNDERSTORMS REACHING SEVERE LEVELS...MAINLY LARGE HAIL.

SWEENEY