Severe Thunderstorm Warning 166, NWS Lake Charles, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
725 AM CDT WED AUG 26 2009

.UPDATE...A FEW SHOWERS POPPING UP OVER SOUTHWEST LOUISIANA. HAVE
THUS GONE AHEAD AND THREW IN SLIGHT CHANCE FOR CONVECTION...AND
BUMPED POPS UP HIGHER FOR SOUTHEAST TEXAS. GRIDS UPDATED AND NEW
ZONES SENT OUT.

MARCOTTE

&&

.PREV DISCUSSION... /ISSUED 637 AM CDT WED AUG 26 2009/

AVIATION...
RADAR IS INDICATING SHOWER DEVELOPMENT FROM ALLEN PARISH IN
SOUTHWEST LOUISIANA TO JEFFERSON COUNTY IS SOUTHEAST TEXAS.
WATCHING THE DEVELOPMENT ALSO SPRING UP ACROSS HARDIN COUNTY AND
THE LAKES REGION IN SOUTHEAST TEXAS. LOOKS LIKE ANOTHER SHORTWAVE
IS ROTATING THROUGH THE BACKSIDE OF THE UPPER LEVEL LOW AND HAVE
ADDED SOME PRECIP TO THE FORECAST ALONG WITH CLOUDS. STORMS WILL
MOVE TO THE SOUTHEAST. VFR CONDITIONS EXPECTED THRU THE MRNG
HOURS EXCEPT IN AND AROUND TSTMS.

K. KUYPER

PREV DISCUSSION... /ISSUED 426 AM CDT WED AUG 26 2009/

DISCUSSION...SATELLITE IMAGERY/SURFACE OBS SHOWING SCATTERED TO
BROKEN STRATOCU ACROSS THE AREA GENERALLY FROM 4-5K FT. RADAR
CURRENTLY CLEAR OF ANY PRECIPITATION. SURFACE ANALYSIS DEPICTING
HIGH PRESSURE OVER THE LOWER MISSISSIPPI VALLEY INTO THE WESTERN
GULF BETWEEN OLD FRONTAL BOUNDARY EXTENDING THROUGH THE EASTERN
GULF WATERS AND NEXT BOUNDARY APPROACHING FROM THE PLAINS. WATER
VAPOR IMAGERY SHOWING MID/UPPER LEVEL LOW SPINNING OVER SOUTHWEST
MISSISSIPPI.

EXPECTING LIMITED CHANCES FOR CONVECTION TODAY AS MOISTURE
PROFILES INDICATING A CAPPED ATMOSPHERE REMAINING IN THE MID AND
UPPER LEVELS. THIS IN A DRY NORTHERLY FLOW BETWEEN AFOREMENTIONED
MISSISSIPPI LOW AND HIGH PRESSURE RIDGING THROUGH THE MID
MISSISSIPPI VALLEY...TEXAS AND OLD MEXICO. SIMILAR SYNOPTIC
PATTERN TO HOLD THROUGH THURSDAY. EXCEPTION TO THIS WILL BE OVER
SOUTHEAST TEXAS WHERE MODELS INDICATING LOW LEVEL MOIST AXIS
REMAINING IN PLACE AND JUST ENOUGH ADDITIONAL MOISTURE TO ALLOW
THE POSSIBILITY FOR THUNDERSTORM DEVELOPMENT AS ANY SHORTWAVE
ENERGY ROTATES ABOUT WESTERN PERIPHERY OF LOW. WITH INVERTED-V
SOUNDINGS PROGGED ACROSS THIS AREA AND UNUSUAL 50-60 KNOT AUGUST
JET ALOFT...COULD NOT RULE OUT THE POTENTIAL FOR DOWNBURST TYPE
CONVECTION.

RAIN CHANCES OVERSPREADING THE ENTIRE AREA FRIDAY AS LOW KICKS OUT
TO THE EAST AND OPENS AS NEXT TROF WITH AN ASSOCIATED COLD FRONT
APPROACHES THE AREA. MODELS DEPICTING INITIAL SHORTWAVE ENERGY TO
ADVANCE FRONT TO THE LAKES AREA LATE FRIDAY...THEN A RATHER SLOW
MIGRATION SOUTHEAST THROUGH THE WEEKEND STALLING OVER THE NEAR
COASTAL WATERS. SHOULD THIS SCENARIO PLAY OUT WILL BE LOOKING AT A
DECREASE IN DEWPOINTS RESULTING IN ANOTHER ROUND OF COOLER NIGHTS
AND LESS HUMID DAYS MOVING INTO THE NEW WORK-WEEK.

MARINE...HIGH PRESSURE CONTINUING TO HOLD OVER THE GULF WATERS
WILL MAINTAIN A LIGHT ONSHORE FLOW INTO THE WEEKEND. A COOL FRONT
WILL POTENTIALLY MOVE INTO THE NORTHWEST GULF LATE SUNDAY INTO
MONDAY RESULTING IN A BRIEF OFFSHORE FLOW.

&&

.PRELIMINARY POINT TEMPS/POPS...
KLCH  92  70  92  73  91 /  20  10  10  10  30
KBPT  92  72  93  71  92 /  30  20  20  20  40
KAEX  92  68  93  70  91 /  20  10  10  10  30
KLFT  91  70  92  72  91 /  20  10  10  10  20

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...AIR QUALITY ALERT UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING
     ZONES: CALCASIEU.

TX...NONE.
GM...NONE.
&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAKE CHARLES LA
520 AM CDT WED AUG 26 2009

GMZ430-432-435-450-452-455-470-472-475-LAZ027>033-041>045-051>055-
TXZ180>182-201-215-216-271030-
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-
520 AM CDT WED AUG 26 2009

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

MINIMAL SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TODAY AND
THESE MAINLY OVER SOUTHEAST TEXAS. ANY THUNDERSTORM DEVELOPMENT
ACROSS THIS AREA WILL HAVE THE POTENTIAL FOR SOME LARGE HAIL AND
DAMAGING DOWNBURST WINDS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

RAIN CHANCES ON THURSDAY WILL AGAIN BE PRIMARILY CONFINED TO
SOUTHEAST TEXAS. SHOWER AND THUNDERSTORM ACTIVITY WILL OVERSPREAD
THE ENTIRE AREA FRIDAY AND INTO THE WEEKEND AS A COLD FRONT
APPROACHES AND MOVES ACROSS THE REGION.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY.