FXUS64 KLCH 151247
AFDLCH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
647 AM CST TUE DEC 15 2009
.AVIATION...
LVFR/IFR CEILINGS/VSBY WITH INTERMITTENT TSRA WILL PREVAIL AT ALL
SITES THIS MORNING. EXPECTING PREDOMINATE +TSRA BY 15Z FOR ALL SITES
AS THE COLD FRONT POOLS THE MOISTURE AND LIFT OVER C LA FOR
KAEX...AND THE SECONDARY TRAINING AREA OF TSRA MOVES N TO AFFECT
KBPT/KLCH/KLFT/KARA. THIS SHOULD PREVAIL THRU 19Z...AND SLOWLY BEGIN
TO DIMINISH AS THE COLD FRONT PUSHES SOUTH...BUT STILL EXPECTING
INTERMITTENT -TSRA THRU 22-23Z THIS AFTERNOON. AFTERWARD...CEILINGS
SHOULD SLOWLY LIFT TO MVFR/VFR THIS EVENING AND OVERNIGHT.
DML
&&
.PREV DISCUSSION... /ISSUED 558 AM CST TUE DEC 15 2009/
DISCUSSION...
BASED ON SFC OBS AND KLCH WSR-88D VAD...THE COLD FRONT HAS
CLEARED LAKE CHARLES WITHIN THE PAST HALF HOUR...AND IS ANALYZED
SUBJECTIVELY TO BE NEAR A LINE FROM JOHNSONS BAYOU TO JUST SOUTH
OF NATCHEZ MISSISSIPPI. LARGE AREA OF RAINFALL...WITH EMBEDDED
THUNDERSTORMS EXTEND WELL NORTH OF THE BOUNDARY. TO THE
SOUTHEAST...THE REMNANT WARM FRONT EXTENDS FROM ABOUT 20 NM SOUTH
OF SABINE PASS EAST NORTHEAST ACROSS SOUTH CENTRAL LOUISIANA NEAR
NEW IBERIA.
SHOWER AND THUNDERSTORM ACTIVITY HAS CONTINUED TO DEVELOP AND
TRAIN ALONG THE REMNANT FRONT OVERNIGHT...WITH DOPPLER ESTIMATES
OF GENERALLY 1 TO 3 INCHES OVER SOUTH CENTRAL LOUISIANA...WITH
ISOLATED AMOUNTS UP TO AROUND 7 INCHES. WILL NOT KNOW FOR SURE HOW
MUCH RAIN FELL UNTIL SOME GROUND TRUTH STARTS COMING IN LATER THIS
MORNING...BUT OBVIOUSLY WITH THE RAIN STILL FALLING AND SOME FLOOD
PROBLEMS ALREADY REPORTED IN STEPHENSVILLE...THE FLOOD WATCH WILL
CONTINUE AS THE RAINFALL IS MAINTAINED OR ENHANCED BY THE ARRIVAL
OF THE COLD FRONT. AN ADDITIONAL 1 TO 4 INCHES ARE POSSIBLE WITHIN
THE WATCH AREA TODAY...WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
RAINFALL WILL GRADUALLY COME TO AN END FROM NORTH TO SOUTH THIS
AFTERNOON AND EVENING...AS DEEPER MOISTURE IS SHUNTED TO THE SOUTH
AND THE ISENTROPIC LIFT WINDS DOWN. CONSIDERABLE HIGH CLOUD COVER
WILL LINGER HOWEVER AS MOISTURE ABOVE 500 MB REMAINS. NORTH WINDS
OVER THE COASTAL COUNTIES/PARISHES WILL BE PUSHING LAKE WIND ADVISORY
CRITERIA BY THIS AFTERNOON...BUT WILL LET DAY SHIFT MONITOR TRENDS
AND EVALUATE NEED.
WE SHOULD GET A BRIEF REPRIEVE FROM RAINFALL ON WEDNESDAY...BUT
MORE RAIN IS LOOMING FOR THURSDAY AS THE FRONT STALLS OVER THE
GULF...AND A SHORTWAVE TO THE WEST INDUCES CYCLOGENESIS OVER THE
WESTERN GULF. THE MODELS...THOUGH IN MUCH BETTER AGREEMENT ON THE
GENERAL IDEA...STILL HAVE SOME RUN-TO-RUN DIFFERENCES ON THE WHERE
AND HOW FAST THE LOW WILL MOVE. PROGS CURRENTLY POINT TO THE BULK
OF THE RAINFALL REMAINING OFFSHORE...BUT IT DOES APPEAR THAT AT
LEAST THE SOUTHERN HALF OF THE AREA AND THE COASTAL WATERS WILL
NOT ESCAPE COMPLETELY. THE DAY SHIFT INSERTED SOME SLIGHT CHANCE
TO LOW END CHANCE POPS THURSDAY AND THURSDAY NIGHT...AND THESE HAVE
BEEN INCREASED...BUT HAVE KEPT LIKELY POPS OVER THE GULF WATERS
FOR NOW.
IN THE WAKE OF THIS SYSTEM...ANOTHER ROUND OF COOLER AND DRIER AIR
COMES IN FOR FRIDAY AND THE WEEKEND...AND WE JUST MAY GET TO SEE
THE SUN AGAIN.
MARINE...
AREAS OF DENSE FOG WILL PERSIST THIS MORNING AS WARM MOIST AIR
OVERRIDES RELATIVELY COOLER WATERS...MAINLY WITHIN 20 NM OF THE
COAST AS WELL AS THE COASTAL LAKES AND BAYS. A COLD FRONT WILL
CROSS THE NORTHWEST GULF BY MID MORNING...BRINGING AN END TO THE
FOG WITH STRONG OFFSHORE FLOW DEVELOPING. NORTHERLY WINDS OF 20
TO 25 KNOTS WITH HIGHER GUSTS WILL BUILD SEAS FROM 4 TO 6 FEET
NEAR SHORE TO 6 TO 9 FEET OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 63 43 55 42 55 / 100 20 10 20 30
KBPT 63 43 55 43 55 / 100 20 10 30 40
KAEX 54 37 51 37 54 / 90 10 10 10 10
KLFT 64 42 54 41 56 / 100 20 10 10 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH UNTIL 5 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: ACADIA...ALLEN...AVOYELLES...CALCASIEU...
CAMERON...EVANGELINE...IBERIA...JEFFERSON DAVIS...
LAFAYETTE...LOWER ST. MARTIN...ST. LANDRY...ST. MARY...
UPPER ST. MARTIN...VERMILION.
TX...FLASH FLOOD WATCH UNTIL 5 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: JEFFERSON...ORANGE.
GM...SMALL CRAFT ADVISORY UNTIL 9 AM CST WEDNESDAY FOR THE FOLLOWING
ZONES: CALCASIEU LAKE...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...SABINE LAKE...VERMILION BAY...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.
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
ZONES: CALCASIEU LAKE...COASTAL WATERS FROM CAMERON, LA TO
HIGH ISLAND, TX OUT 20 NM...COASTAL WATERS FROM
INTRACOASTAL CITY TO CAMERON, LA OUT 20 NM...SABINE LAKE.
&&
$$
