AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 917 PM CDT THU JUL 7 2011 .UPDATE... LAST OF ISOLATED SHOWERS AND THUNDERSTORMS HAVE DISSIPATED OVER LAND WHILE A FEW SHOWERS APPROACH THE OUTERMOST EASTERN COASTAL WATERS. STABILIZED CONDITIONS OVER LAND SHOULD MEAN A VERY LOW /LESS THAN 10 PERCENT/ CHANCE OF RAIN THE REMAINDER OF THE NIGHT. AREAS OF MID/HIGH CLOUDS WRAPPING AROUND UPPER LOW WILL ALTERNATELY THICKEN AND THIN OVERNIGHT LEADING TO OVERALL PARTLY CLOUDY SKIES. MAINLY ISOLATED NOCTURNAL SHOWERS AND THUNDERSTORMS ARE EXPECTED AFTER MIDNIGHT ACROSS THE COASTAL WATERS...AND A FEW OF THESE COULD BRIEFLY IMPACT THE IMMEDIATE COASTAL AREAS. 22/TD && .SOUNDING DISCUSSION... OVERALL SOUNDING PROFILE IS NOT VERY SATURATED DESPITE THE 1.92 INCHES OF PRECIPITABLE WATER...AND THE MID LEVEL LAPSE RATES ARE RELATIVELY LOW. THIS EXPLAINS THE LACK OF COVERAGE AND INTENSITY OF THE SHOWERS AND THUNDERSTORMS TODAY. WINDS REMAIN FAIRLY WEAK...GENERALLY LESS THAN 10 KNOTS BELOW 500 MB...AND EASTERLY AROUND 30 KNOTS IN THE UPPER LEVELS. && .AVIATION... VFR CONDITIONS WILL PREVAIL THE REMAINDER OF TONIGHT AT MOST OF THE AIRPORTS. THERE IS A 20 TO 30 PERCENT CHANCE OF SHRA/TSRA MAINLY DURING THE AFTERNOON HOURS ON FRIDAY. HAVE A BRIEF PROB30 GROUP FOR NOW FOR A 2-3 HOUR PERIOD. 22/TD .PREV DISCUSSION... /ISSUED 354 PM CDT THU JUL 7 2011/ SHORT TERM... SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO DEVELOP AND DISSIPATE MAINLY ACROSS THE COASTAL PARISHES/COUNTIES. THINKING IS THAT EACH CELL IS DECEIVINGLY SMALL IN AREAL SIZE. PRECIPITAL WATER ON THE 12Z SOUNDING WAS AROUND 2 INCHES. WITH THAT MUCH MOISTURE IN THE COLUMN...RAIN EFFICIENCY IS LIKELY QUITE HIGH. WEAK WINDS ALOFT INDICATE SLOW MOVEMENT WILL CONTINUE. THUS...VERY HEAVY DOWNPOURS ARE LIKELY WITH STRONGER STORMS AND WATER COULD BEGIN COVERING FLOOD PRONE ROADS QUICKLY FOR A SHORT DURATION. THE GOOD NEWS ABOUT MORE MOISTURE IN THE SOUNDING IS THAT THERE LESS DRY AIR TO LEAD TO DAMAGING WIND GUSTS. THATS NOT TO SAY THERES NO POTENTIAL B/C PRECIP LOADING CAN LEAD TO WET MICROBURST. REGARDLESS...INLAND ACTIVITY IS MOSTLY DIURNALLY DRIVEN AND SHOULD DISSIPATE AROUND SUNSET. LONG TERM... SIMILAR CONDITIONS ARE EXPECTED AGAIN FRIDAY AND SATURDAY EXCEPT FOR POSSIBLY SLIGHTLY HIGHER COVERAGE. DID BUMP UP TEMPS A COUPLE DEGREES OVER THE WEEKEND. MAV HAS BEEN TRENDING UPWARDS ON THESE VALUES ON THE LAST FEW RUNS. NOT QUITE AS HOT FOR HIGHS BUT ONLY A DEGREE OR SO BELOW. KEPT BELOW DUE TO TRENDS LATELY. TROPICAL WAVE OVER THE EASTERN GULF OF MEXICO HAS CHANGED LITTLE IN ORGANIZATION OVER THE LAST 24 HOURS. THE PROBABILITY OF THIS WAVE DEVELOPING INTO ANYTHING ORGANIZED IS LOW. AN UPPER LOW SOUTH OF LOUISIANA IS PRODUCING HIGH WIND SHEAR ON THE SYSTEM AND THUS IMPEDING DEVELOPMENT. GFS COMPLETELY DISSIPATES THE WAVE TOMORROW WHILE ECMWF AND NHC/HPC BRING THE WAVE NORTHWARD INTO THE FLORIDA PANHANDLE TOWARDS A WEAKNESS ON THE EAST SIDE OF UPPER RIDGE OVER SOUTHERN HALF OF THE COUNTRY WITH NO ADDITIONAL DEVELOPMENT. ATTM...NO IMPACTS EXPECTED. WILL CONTINUE TO MONITOR. UPPER LEVEL RIDGE WILL BE SHIFTING EASTWARD FROM TODAY THROUGH EARLY NEXT WEEK. AS THE RIDGE NEARS...HEIGHTS WILL BE INCREASING AND THUS TEMPS TO RISE SLIGHTLY. AT THE SAME TIME...MODELS SUGGEST OVERALL MOISTURE LEVELS TO INCREASE...WITH SFC DEWPOINTS IN THE MID 70S BY MONDAY. THE COMBINATION WILL LEAD TO INCREASED HEAT INDICES AS WELL AS INCREASED CONVECTION. BASICALLY...IF NOT UNDER A THUNDERSTORM... EXPECT HEAT INDEX OVER 105. SO...HEAT ADVISORY NOT OUT OF THE QUESTION NEXT WEEK. MEFFER AVIATION... AS HAS BEEN THE CASE THE LAST FEW DAYS...VFR CONDITIONS WILL PERSIST OUTSIDE OF CONVECTION. SCT CU FROM 3-5K FT DEVELOPED OVER MUCH OF THE AREA LATE THIS MORNING BUT BY 20Z HAS ALREADY STARTED TO THIN OUT. CONVECTION HAS BEEN SLOW TO DEVELOP BUT IF IT IMPACTS THE TERMINALS LOOK FOR THE TYPICAL REDUCTIONS IN VISBIES AND LOWERED CIGS. GUSTY WINDS ARE ALSO LIKELY WITH ANY TSRA OR OUTFLOW INDUCED TSRA. ALL CONVECTION SHOULD QUICKLY COME TO AN END AROUND 1/2Z WITH MOST OF THE AREA UNDER SKC BY 3-4Z. LOOK FOR LIGHT SFC WINDS AND FEW-SCT CU AROUND 4-5K FT AGAIN TOMORROW BEGINNING AROUND 1530Z. /CAB/ MARINE... NO SIGNIFICANT CHANGES MADE TO THE COASTAL WATER FORECAST. SURFACE PRESSURE PATTERN WILL REMAIN FAIRLY WEAK THROUGH THE PERIOD. WINDS WILL REMAIN MOSTLY SOUTHWESTWARD AT 5 TO 10 KNOTS OR EVEN LESS. THIS MEANS SEAS GENERALLY AROUND A FOOT OR LESS TO BE EXPECTED. MEFFER && .PRELIMINARY POINT TEMPS/POPS... MCB 94 72 95 73 / 30 20 30 20 BTR 94 74 95 76 / 30 20 20 20 ASD 93 74 94 77 / 30 20 30 20 MSY 93 78 93 78 / 30 20 20 20 GPT 94 75 93 77 / 30 10 30 20 PQL 93 71 94 74 / 30 10 30 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$