843 FXUS64 KLCH 190300 AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 1000 PM CDT TUE JUN 18 2013 .DISCUSSION... LOCAL 88DS SHOW CONVECTION ASSOCIATED WITH ADVANCING SHORTWAVE ENERGY ALOFT AND AN OUTFLOW FROM EARLIER STORMS IS STEADILY DISSIPATING AS IT PUSHES EWD ACROSS THE AREA. AIRMASS ACROSS THE FORECAST AREA SHOULD BE FAIRLY WELL WORKED OVER THANKS TO THIS LATEST ROUND OF CONVECTION BUT WITH A JUICY AIRMASS LINGERING AND THE SHORTWAVE SLOWLY CROSSING THE AREA OVERNIGHT...ONLY LOWERED POPS A LITTLE FROM PREVIOUS FORECAST...PRIMARILY OVER THE WRN 1/2 OF THE AREA. OTHERWISE JUST MINOR TWEAKS TO INHERITED GRIDS/FORECASTS BASED ON LATEST TRENDS. UPDATE OUT SHORTLY. 25 && .PREV DISCUSSION... /ISSUED 642 PM CDT TUE JUN 18 2013/ AVIATION...A BAND OF SHOWERS AND THUNDERSTORMS MOVING OUT AHEAD OF A STATIONARY FRONTAL BOUNDARY IS PUTTING OUT AN OUTFLOW BOUNDARY THAT LOOKS TO BE AN HOUR OUT OF LCH. SINCE THIS BOUNDARY IS MOVING SOUTHEAST AT 20 KNOTS, WILL INCLUDE A TEMPO FOR NW WINDS GUSTING 20 TO 30 KNOTS WITH POSSIBLE TSTMS PRODUCING MVFR VIS AT LCH FOR THE NEXT FEW HOURS. MVFR VIS IN WEAKENING TSTMS AROUND AEX BUT POSSIBLE STRONGER STORMS AN HOUR OUT MOVING IN FROM THE SW WITH IFR VIS. BPT COULD SEE WEAK MVFR TSTMS OVER THE NEXT COUPLE OF HOURS AS THE BAND HANGS UP JUST TO THE NORTH WITH POSSIBLE NEW DEVELOPMENT NEAR THE OUTFLOW BOUNDARY. THE ACADIANA AIRPORTS LOOK TO BE SUITABLE ALTERNATES WITH VFR CONDITIONS. SWEENEY PREV DISCUSSION... /ISSUED 243 PM CDT TUE JUN 18 2013/ SYNOPSIS... A STATIONARY FRONT EXTENDS THROUGH GREENWOOD MS THROUGH TYLER THIS EVENING...WILL OSCILLATE NORTH AND SOUTH OVER THE NEXT FEW DAYS. THE BERMUDA HIGH PRESSURE SYSTEM RIDGES WESTWARD THROUGH SOUTH FLORIDA AND INTO THE GULF OF MEXICO. FURTHER UP...A DOME OF HIGH PRESSURE ACROSS OLD MEXICO WILL DRIFT NORTHEAST OVER THE NEXT FEW DAYS. THIS SEMI-PERMANENT ANTICYCLONE WILL TAKE ON A POSITIVE TILT ON SATURDAY...WITH RIDGE AXIS EXTENDING THROUGH WEST TEXAS TO ILLINOIS. DISCUSSION... A LIFTING MECHANISM IS SETTING UP ACROSS THE WESTERN UPPER GULF COAST STATES. THE OUTER WESTERN PERIPHERY OF THE BERMUDA HIGH PRESSURE SYSTEM IS STEERING CARIBBEAN AIR THROUGH THE NORTHWEST GULF OF MEXICO. THE TRAVELING CARIBBEAN AIR ASCENDS UPON APPROACHING THE STATIONARY FRONT (TROUGH OF LOWER PRESSURE). FURTHER UP...THE GFS MODEL DEPICTS A VIGOROUS WESTERLY SHORTWAVE TRAVELING INTO WESTERN LOUISIANA THIS EVENING...BEFORE EXITING INTO MISSISSIPPI BY WEDNESDAY EVENING. THE INGREDIENTS FOR SHOWERS AND THUNDERSTORMS WILL IS IN PLACE TONIGHT. THE COMBINED LIFT WILL BE ADEQUATE. THE LIFT ATTENDING THE UPSLIDING CARIBBEAN AIR WILL GET AN ADDITIONAL BOOST FROM THE TRAVELING WESTERLY SHORTWAVE. MOISTURE WILL BE ADEQUATE AS WELL WITH PRECIPITABLE WATER RUNNING SLIGHTLY ABOVE 2 INCHES (ABOUT 2 STANDARD DEVIATIONS ABOVE THE MID-JUNE BENCHMARK NORMALS). INSTABILITY WILL BE ADEQUATE. THE K-INDEX WILL BE RUNNING IN THE MID TO UPPER 30'S (CELSIUS DEGREES). THE POTENTIAL CONVECTIVE INSTABILITY BE RUNNING AROUND 3000 J PER KG THIS EVENING. ISOLATED SEVERE WEATHER IS POSSIBLE (MICROBURSTS). HOWEVER...THE PRIMARY THREAT WILL BE LOCALIZED FLOODING RAIN. 21 && .PRELIMINARY POINT TEMPS/POPS... KLCH 74 89 75 91 75 / 60 50 10 30 10 KBPT 75 90 75 91 75 / 60 50 10 20 10 KAEX 71 88 71 91 72 / 60 50 10 30 10 KLFT 74 89 75 91 75 / 60 50 30 30 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$