FXUS64 KLIX 100045 AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 745 PM CDT SAT MAY 9 2009 .UPDATE... ...SOUNDING DISCUSSION... THE ATMOSPHERE REMAINS UNSTABLE AND FAIRLY MOIST WITH A LIFTED INDEX VALUE OF -6.9 AND A PRECIPITABLE WATER VALUE OF 1.12 INCHES. CUMULUS CLOUDS HAVE BEEN PRESENT THROUGHOUT THE DAY BUT NO SIGNIFICANT VERTICAL CLOUD GROWTH HAS OCCURRED DUE TO AN INVERSION AND DRY AIR ABOVE 825 MILLIBARS. WINDS ARE OUT OF THE SOUTHWEST NEAR THE SURFACE AND OUT OF THE WEST ALOFT. && .PREV DISCUSSION... /ISSUED 332 PM CDT SAT MAY 9 2009/ DISCUSSION... LATEST SURFACE ANALYSIS CONTINUE TO SHOW A 1021MB HIGH OVER THE EAST GULF AND A 1012MB LOW OVER THE NORTHEAST TEXAS. A NEARLY STATIONARY FRONT WAS ALONG THE LOW TO THE NORTHEAST AND TO THE SOUTHWEST. DEWPOINT READINGS OF 65 TO 70F WERE COMMON ACROSS MISSISSIPPI AND LOUISIANA. LIX SOUNDING REVEALED A CAP ONLY SURFACE TEMPS IN THE MID 90S COULD BREAK. AS A RESULT...A CU FIELD COULD ONLY DEVELOP ACROSS THE CENTRAL GULF COAST THIS AFTERNOON. LURKING UP NORTH NEAR THE BOUNDARY CONVECTION CONTINUED ACROSS THE ARKLATEX REGION. INITIALIZED SOUNDINGS OFF OF NAM12 AND GFS STILL TOO COOL AT 12Z AND THIS HANDLE OF MID LAYER TEMPS PROMPTS OUR TO FORECASTERS TO THINK SUNDAY MAY STILL BE TOO WARM. SOME COOLING ALOFT MAY OCCUR WITH WINDS BECOMING MORE WEST ON SUNDAY...STILL WILL SHAVE RAIN CHANCES A TAD TO THURSDAY...ESPECIALLY ALONG THE LOUISIANA COAST. WILL MAINTAIN CHANCE POPS ACROSS THE NORTHERN ZONES AS THE SURFACE FRONTAL BOUNDARY SAGS SUNDAY. UPPER LEVEL DYNAMICS AND JET SHOULD REMAIN NORTH AND ONLY A VERY SLIGHT RISK OF SEVERE THUNDERSTORMS WITH STRONG WINDS ARE POSSIBLE ACROSS EXTREME SOUTHWEST MISSISSIPPI SUNDAY AND SUNDAY EVENING. FRONTAL BOUNDARY WILL REMAIN STATIONARY WEST/EAST JUST NORTH SUNDAY NIGHT BUT SAG SOUTH INTO THE FORECAST AREA MONDAY. UPPER LEVEL RIDGE WILL SLIGHT AMPLIFY OVER TEXAS AND UPPER LEVEL TROUGH DEEPENS OVER THE OHIO VALLEY WILL LEAD TO A NORTHWEST FLOW ALOFT WITH EMBEDDED DISTURBANCES MONDAY AFTERNOON. WITH FRONTAL FOCUS...SURFACE HEATING TO INCREASE INSTABILITY AND NORTHWEST WINDS ALOFT TO ENHANCE WIND PROFILES...BETTER CHANCE OF CONVECTION AND POSSIBLY STRONG TO MAYBE SEVERE CONVECTION ON MONDAY...WIND DAMAGE WILL BE THE MAIN THREAT. TUESDAY...FRONTAL BOUNDARY WILL PULL NORTH/POSSIBLY DISSIPATE. PRECIPITABLE WATER VALUES WILL REMAIN AROUND 1.5 TUESDAY INTO EARLY WEDNESDAY...WILL MAINTAIN SLIGHT CHANCES. GFS AND ECMWF BRING SOME DRY AIR FROM THE WEST GULF OVER THE WEST PARTS OF THE FORECAST AREA WEDNESDAY AND WEST ZONES CHANCE OF RAIN WILL BE SLIMMER THAN EAST ZONES WEDNESDAY AND THURSDAY. ANOTHER COLD FRONT APPROACH LATE THURSDAY WILL ALLOW MOISTURE TO RETURN OVER THE AREA AND MAINTAIN A CHANCE OF CONVECTION FOR NEXT WEEKEND. 18 AVIATION... PRETTY MUCH A PERSISTENCE FORECAST THROUGH 18Z SUNDAY. OCCASIONAL MVFR CIGS FOR A FEW HOURS AROUND SUNRISE AT SOME TERMINALS...OTHERWISE VFR CONDITIONS. FRONTAL BOUNDARY SAGGING DOWN FROM NORTH COULD CONCEIVABLY PRODUCE ISOLATED CONVECTION AT KBTR AND KMCB BY TOMORROW AFTERNOON...BUT PROBABILITIES/AREAL COVERAGE WILL NOT BE HIGH ENOUGH TO MENTION IN TAFS IN 00Z PACKAGE. 35 MARINE... WINDS ARE SOMEWHAT LIGHTER THIS AFTERNOON AS GRADIENT HAS WEAKENED. A WEAK SLOWLY MOVING TROUGH WILL STALL AND WEAKEN NEAR THE COAST MONDAY AND A FEW THUNDERSTORMS COULD DEVELOP NEAR SHORE. LARGE SCALE RIDGING WILL COMMENCE ONCE AGAIN OVER THE AREA FOR THE REMAINDER OF THE WEEK. WINDS GENERALLY WILL REMAIN UNDER 15 KNOTS AND SEAS GRADUALLY DROPPING INTO THE 1 TO 3 FOOT RANGE WHERE THEY HAVEN'T ALREADY FALLEN. 35 && .PRELIMINARY POINT TEMPS/POPS... MCB 68 88 67 82 / 10 30 20 40 BTR 69 89 69 86 / 10 20 10 30 MSY 71 88 71 86 / 10 20 10 30 GPT 71 83 70 83 / 10 20 10 30 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$