FXUS64 KLCH 071624
AFDLCH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1024 AM CST MON DEC 7 2009
.UPDATE...
A COLD FRONT PUSHED THROUGH THE REGION THIS MORNING...THE BOUNDARY
IS NOW LOCATED BEYOND 60 MILES OF THE TEXAS/LOUISIANA COAST.
SHOWERS AND ISOLATED THUNDERSTORMS WERE FIRING ALONG AND AHEAD OF
THE FRONTAL BOUNDARY.
AREAS OF FOG HAVE DEVELOPED OVER THE REGION WITH FOG DENSER ALONG
THE COAST AND COASTAL WATERS. THIS WILL CONTINUE INTO THE AFTN
HOURS WITH SOME RAIN/DRIZZLE MIXED FOR SE TX AND SRN LA.
THIS LATEST BOUNDARY IS EXPECTED TO RETREAT BACK TO THE NORTH THIS
EVE WITH MORE SHOWERS ON TAP.
&&
.PREV DISCUSSION... /ISSUED 654 AM CST MON DEC 7 2009/
UPDATE...
MADE SOME ADJUSTMENTS TO THE POP/WX GRIDS FOR THIS MORNING AS
SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE OFF TO THE EAST.
REMOVED POPS GENERALLY WEST OF A LINE FROM MARKSVILLE TO THE COAST
NEAR GRAND CHENIER FOR THIS MORNING. REMAINDER OF FCST PARAMETERS
ARE GOOD AT THIS TIME. UPDATED ZONE PACKAGE WILL BE
ISSUED...MAINLY TO ADJUST WORDING ACRS CNTRL LA ZONES AND SW LA
ZONES. IN ADDITION...HAVE ISSUED AN UPDATED COASTAL FCST TO REMOVE
SMALL CRAFT ADVISORY WHICH EXPIRED AT 6 AM.
PREV DISCUSSION... /ISSUED 526 AM CST MON DEC 7 2009/
AVIATION...
FOR THE 07/12Z TAF ISSUANCE...
ONE BATCH OF SHOWERS IS MOVING ACROSS CENTRAL AND SOUTHERN
LOUISIANA AND SHOULD BE EXITING THE AREA EARLY THIS MORNING. WILL
LEAVE A FEW SHOWERS IN THE TAFS FOR KAEX/KLFT/KARA THROUGH ABOUT 07/15Z.
REMAINDER OF THE DAY A COLD FRONT WILL BE STALLING OVER THE
REGION. EXPECT MVFR/IFR CEILINGS TO CONTINUE THROUGH THE DAY WITH
ISENTROPIC LIFT PREVAILING OVER THE FRONTAL SYSTEM.
A BAND OF RAIN SHOULD OVERTAKE THE FORECAST AREA TONIGHT AS NEXT
STRONG UPPER LEVEL DISTURBANCE MOVES ACROSS THE REGION. A FEW
THUNDERSTORMS WILL ALSO BE POSSIBLE AT THE SOUTHERN TAF SITES
AFTER MIDNIGHT.
RUA
PREV DISCUSSION... /ISSUED 500 AM CST MON DEC 7 2009/
SYNOPSIS...
BROAD SWATH OF ZONAL FLOW NOTED ACROSS MUCH OF THE CONUS PER THIS
MORNINGS WATER VAPOR IMAGERY WITH A TROUGH DIGGING INTO THE WRN
STATES. AT THE SFC...AN INVERTED TROUGH/FRONTAL BOUNDARY LOCATED
ALONG A ROUGHLY GWO-LCH LINE EXTENDED INTO THE NWRN GULF. WINDS
AHEAD OF THE FRONT WERE FROM THE EAST TO SOUTHEAST WHILE ON THE
BACKSIDE NORTHERLY WINDS HAVE DEVELOPED OVER WRN LA INTO SE TX.
TEMPERATURES ACROSS THE REGION WERE IN THE MID TO UPPER 50S.
RADAR MOSAIC SHOWS SCATTERED SHOWERS IN ASSOCIATION WITH THE SFC
TROUGH ACRS CNTRL AND SRN LA...WITH A BROKEN LINE OF SHOWERS AND
THUNDERSTORMS EXTENDING FM THE SW LA COAST ACRS THE NW GULF.
DISCUSSION...
SFC FRONT WILL STALL THIS MORNING ACRS FAR S CNTRL LA AND THE
COASTAL WATERS FROM MARSH ISLAND SW TO AROUND 60 NM SE OF HIGH
ISLAND. EXPECT CLOUD COVER TO LINGER THROUGH THE DAY WITH SOME
BREAKS POSSIBLE DURING THE MORNING...MAINLY ACRS SE TX. RAIN
CHANCES WILL BE LOW OVER WRN PORTIONS OF THE AREA THIS
MORNING ON THE BACKSIDE OF THE TROUGH/FRONT WITH SLIGHTLY DRIER
AIR FILTERING IN BRIEFLY. CHC POPS EXPECTED OVER ERN AREAS IN THE
VICINITY OF THE STALLING BOUNDARY. EXPECT POPS TO INCREASE AGAIN
DURING THE AFTN OVER WRN AREAS AS ADDITIONAL PERTURBATIONS IN THE
SOUTHWESTERLY FLOW ALOFT COMBINE WITH ISENTROPIC FORCING.
TEMPERATURES NOT EXPECTED TO WARM MUCH TODAY WITH WEAK COOL AIR
ADVECTION AT THE SFC DUE TO NORTHEASTERLY WINDS...ALONG WITH
CLOUDY SKIES. HOWEVER...IF ANY AREAS ARE ABLE TO SEE SUFFICIENT
SUN...MAINLY OVER SE TX AND WRN LA...TEMPERATURES COULD BE
SLIGHTLY WARMER.
BY TONIGHT...THE FRONT WILL LIFT BACK NORTH AS A WARM FRONT WITH
SOUTHERLY WINDS DEVELOPING. EXPECT SHOWERS TO INCREASE OVERNIGHT
AS THE LOW LEVEL JET STRENGTHENS OVER THE REGION...ALONG WITH
DEEPENING MOISTURE. TUESDAY LOOKS BE A RATHER ACTIVE DAY ACRS THE
AREA...WITH A 50 TO 60 KNOT LLJ DEVELOPING AND DEWPOINTS
APPROACHING 70 DEGREES AS WARM MOIST AIR ADVECTS NORTH ACRS THE
AREA. SPC CONTINUES TO PLACE THE AREA IN A SLT RISK FOR SEVERE
WEATHER AS SUFFICIENT DEEP LAYER SHEAR WILL BE IN PLACE...WITH THE
POTENTIAL FOR DAMAGING WINDS AND A FEW TORNADOES.
DRIER AIR WILL BEGIN TO MOVE INTO THE AREA OVERNIGHT TUESDAY AS
THE FRONT PUSHES THROUGH BY EARLY WEDNESDAY MORNING. DRIER AND
COOLER WEATHER WILL RETURN TO THE AREA WEDNESDAY INTO THURSDAY AS
CANADIAN HIGH PRESSURE BUILDS INTO THE REGION. BELOW NORMAL
TEMPERATURES ARE EXPECTED...WITH THE COOLEST TEMPERATURES EXPECTED
ON THURSDAY MORNING WITH LOWS IN THE MID 30S NORTH TO LOWER 40S
SOUTH.
PROGRESSIVE PATTERN TO CONTINUE THROUGH THE EXTENDED AS
PREDOMINANTLY ZONAL FLOW CONTINUES ALOFT. LOOKS LIKE NEXT CHANCE
FOR RAIN COMES LATE FRIDAY INTO SATURDAY AS ANOTHER GULF LOW
DEVELOPS AND MOVES EAST OF THE AREA. TEMPERATURES TO REMAIN NEAR
OR SLIGHTLY BELOW NORMAL.
MARINE...
A FRONT MOVING EAST ACROSS THE COASTAL WATERS THIS MORNING WILL
STALL TODAY AND LIFT BACK NORTH TONIGHT RESULTING IN A VARIABLE
WIND PATTERN. WINDS SHOULD MAINTAIN AN SOUTHEAST TO SOUTH
DIRECTION MAINLY EAST OF CAMERON...WHILE WEST OF CAMERON WINDS
WILL BE WEST THIS MORNING VEERING TO A SOUTHERLY DIRECTION BY
TONIGHT. BY TUESDAY...STRONG ONSHORE FLOW WILL DEVELOP WITH WINDS
INCREASING TO AROUND 20 KNOTS BY AFTN ALONG WITH SEAS BUILDING TO
6 TO 8 FEET...AND ACCOMPANIED BY NUMEROUS SHOWERS AND
THUNDERSTORMS. ON WEDNESDAY...THE FRONT WILL MOVE BACK TO THE
SOUTH...WITH OFFSHORE WINDS DEVELOPING DURING THE MORNING AND
CONTINUING THROUGH THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 61 56 75 59 68 / 60 80 70 30 0
KBPT 60 55 74 56 68 / 60 80 70 20 0
KAEX 55 50 71 54 62 / 60 80 70 30 0
KLFT 65 59 76 60 70 / 60 80 70 40 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: CAMERON...IBERIA...LOWER ST. MARTIN...ST. MARY...
VERMILION.
TX...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: JEFFERSON.
GM...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING 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.
&&
$$
