000 FXUS64 KLCH 241102 AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 502 AM CST TUE NOV 24 2009 .DISCUSSION... FOR 12Z TAF ISSUANCE. && .AVIATION... LATEST OBSERVATIONS SHOW PATCHY DENSE FOG ONGOING AROUND THE REGION WITH MANY SITES REPORTING VISIBILITIES LESS THAN 1SM. ACCORDINGLY MOST LOCATIONS ALSO SHOWING VLIFR CEILINGS. KARA IS THE MAIN OUTLIER THIS MORNING WITH CLEAR SKIES AND 10SM. INITIAL PROBLEM WITH THIS TAF PACKAGE IS THE HANDLING OF THE FOG/LOW CLOUDS. WITH THE EXCEPTIONS OF KARA AND KBPT EXPECT AT LEAST TEMPO 1/4SM FG VV001 THROUGH 14Z WITH A QUICK IMPROVEMENT TO P6SM BY 16Z ALTHOUGH WITH MVFR CEILINGS LIKELY TO REMAIN. AT KBPT CARRYING TEMPO 2SM AND 300 FEET THROUGH 14Z...WHILE AT KARA CARRYING TEMPO 2SM AND 1000 FEET BASED MAINLY ON THE LATE FOG FORMATION YESTERDAY MORNING. ONCE THE VISIBILITIES AND CEILINGS IMPROVE NEXT PROBLEM OF THE DAY WILL BE CONVECTION ASSOCIATED WITH SFC FRONT BEGINNING LATE THIS MORNING. REGIONAL 88DS SHOW SCATTERED SHOWERS/FEW STORMS ALREADY FORMING OFF THE MIDDLE TX COAST WHICH BOTH THE GFS/NAM SHOW REMAINING MOSTLY OFFSHORE. MODELS ARE FAIRLY SIMILAR IN THEIR TIMING WITH BRINGING PRECIP ALONG THE FRONT THROUGH THE REGION SO HAVE TIMED THIS SHOWER ACTIVITY WITHIN TEMPO GROUPS AHEAD/ALONG THE FRONT BEGINNING AT KBPT AT 16Z. WINDS SHIFT AROUND TO THE NORTH BEHIND THE FRONT AND SKIES SHOULD GRADUALLY CLEAR. 25 && .PREV DISCUSSION... /ISSUED 444 AM CST TUE NOV 24 2009/ SYNOPSIS... AT THE SFC...FOG HAS DEVELOPED AREAWIDE THIS MORNING AS A RESULT OF LIGHT WINDS AND MOSTLY CLEAR SKIES. FOG HAS BEEN DENSE IN A FEW AREAS WITH VISBYS OCCASIONALLY DOWN TO ONE QUARTER OF A MILE...BUT NOT WIDESPREAD ENOUGH TO REQUIRE A DENSE FOG ADVISORY AT THIS TIME. FOR THE MOST PART...VISBYS HAVE BEEN FLUCTUATING FROM ONE QUARTER TO ONE MILE IN LOCATIONS WITH THE DENSEST FOG. A SFC FRONT WAS LOCATED FROM NEAR FORT SMITH ARK TO NEAR BRYAN TX. AREA RADAR MOSAIC SHOWS SOME SHOWERS OVER ARK...WITH ONLY SOME FINE LINE RETURNS OVER TX. FURTHER SOUTH...SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OFF THE TX COAST NEAR MATAGORDA BAY IN RESPONSE TO A DISTURBANCE APPROACHING THE GULF OF MEXICO. IN THE UPPER LEVELS...A LOW IS NOTED ON WATER VAPOR IMAGERY SPINNING OVER KS...PLACING THE AREA UNDER SWRLY FLOW ALOFT. DEEPEST MOISTURE IS LOCATED FURTHER SOUTH OVER THE GULF. DISCUSSION... FOG IS EXPECTED TO BURN OFF BY MIDMORNING WITH PARTLY CLOUDY SKIES DEVELOPING BY LATE MORNING. THE COLD FRONT WILL MOVE THROUGH THE AREA TODAY AS THE UPPER LOW CURRENTLY OVER THE CNTRL PLAINS LIFTS NE TOWARD THE GREAT LAKES. MOISTURE AND INSTABILITY STILL LOOK FAIRLY LIMITED ACROSS THE AREA TODAY. KEPT A LOW END CHC FOR SHOWERS DURING THE AFTERNOON MAINLY ALONG THE FRONTAL BOUNDARY. COULD SEE A FEW ISOLATED THUNDERSTORMS OVER THE SWRN ZONES WHERE HIGHER DEWPOINTS AND BETTER INSTABILITY WILL BE LOCATED. AHEAD OF THE FRONT...TEMPERATURES ARE EXPECTED TO WARM INTO THE LOWER 70S. OVER THE NWRN ZONES...HIGHS WILL BE A LITTLE COOLER AS THE FROPA HERE IS EXPECTED BY LATE MORNING TO MIDDAY. RAIN CHANCES EXPECTED TO DROP OFF RATHER QUICKLY IN THE WAKE OF THE FRONT AS DRY HIGH PRESSURE BUILDS INTO THE REGION. TEMPERATURES WILL RUN NEAR SEASONAL VALUES TONIGHT INTO WEDNESDAY. IN THE WAKE OF THE FIRST LOW...ANOTHER SHORTWAVE WILL DROP OUT OF CANADA INTO THE CNTRL CONUS TROUGH WEDNESDAY INTO THURSDAY. THIS WILL PUSH A REINFORCEMENT OF COOL DRY AIR ACRS THE AREA. WITH HIGH PRESSURE AT THE SFC AND DRY NWRLY FLOW ALOFT...EXPECT NICE AND COOL WEATHER CONDITIONS FOR THE THANKSGIVING HOLIDAY INTO THE WEEKEND. TEMPERATURES WILL BE NEAR OR A BIT BELOW SEASONAL NORMS WITH LOWS GENERALLY IN THE 40S AND HIGHS IN THE 60S. THE COOLEST TEMPERATURES ARE EXPECTED THANKSGIVING NIGHT INTO FRIDAY MORNING WITH LOWS IN THE MID TO UPPER 30S MAINLY NORTH OF INTERSTATE 10. TEMPERATURES WILL BEGIN TO WARM BY LATE IN THE WEEKEND AS HIGH PRESSURE MOVES EAST AND RETURN FLOW SETS UP. ANOTHER SYSTEM WILL BE TAKING SHAPE OVER THE WRN US LATE NEXT WEEKEND WITH A CHANCE FOR SHOWERS RETURNING SUNDAY AFTN AHEAD OF THE NEXT FROPA ON MONDAY. MARINE... LIGHT SOUTHERLY WINDS WILL SHIFT EAST THEN NORTH TODAY AS A COLD FRONT MOVES ACROSS THE COASTAL WATERS. MODERATE TO STRONG OFFSHORE FLOW WILL DEVELOP BEHIND THE FRONT TONIGHT INTO EARLY WEDNESDAY WITH WINDS INCREASING TO 15 TO 20 KNOTS. SEAS ARE EXPECTED TO BUILD TO 4 TO 6 FEET TONIGHT...PRIMARILY FROM 20 TO 60 NM OFFSHORE. HAVE HELD OFF ON ISSUING SMALL CRAFT ADVISORY AT THIS TIME WITH CONDITIONS EXPECTED TO REMAIN BELOW CRITERIA...AND INSTEAD WENT WITH EXERCISE CAUTION FOR TONIGHT. MODERATE NORTHERLY FLOW WILL PERSIST THROUGH THE REMAINDER OF THE WEEK WITH HIGH PRESSURE REMAINING OVER THE AREA. && .PRELIMINARY POINT TEMPS/POPS... KLCH 73 48 68 42 66 / 40 10 0 0 0 KBPT 72 46 67 41 66 / 40 10 0 0 0 KAEX 70 44 65 38 63 / 30 10 0 0 0 KLFT 74 49 68 41 64 / 30 20 0 0 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$