000 FXUS64 KLIX 061926 AAA AFDLIX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE NEW ORLEANS LA 226 PM CDT MON JUL 6 2009 .AVIATION... VFR CONDITIONS WILL PREVAIL OUTSIDE OF SHRA/TSRA AREAS. MAIN CONCERNS ARE WITH TIMING THE CONVECTION. THE NEAR TERM PORTION OF THE FORECAST IS BASED MOSTLY ON RADAR TRENDS WHICH SHOW THE STRONGER TSRA SHIFTING SOUTH WITH A SURFACE TROUGH/THUNDERSTORM OUTFLOW BOUNDARY. LATER INTO TONIGHT AND TUESDAY...ADDITIONAL UPPER LEVEL DISTURBANCES WILL CAUSE SCATTERED SHRA/TSRA TO DEVELOP WHICH WILL BE HARD TO TIME IN THE TAFS. 22/TD && .PREV DISCUSSION... /ISSUED 928 AM CDT MON JUL 6 2009/ UPDATE... LARGE CLUSTER OF SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS CENTRAL LA/SOUTHERN MS AND INTO SERN LA. TEMPS HAVE BEEN SLOW TO RISE ALONG AND NORTH OF I-12...SO HAVE ADJUSTED EXPECTED HIGHS ACCORDING LING. SOUTH OF THE INTERSTATE WILL SEE MORE SCATTERED CONVECTION AND SHOULD WARM UP MORE TO PREVIOUS FORECAST. ALSO INCREASED POPS TO BETTER MIMIC CURRENT TRENDS. PREV DISCUSSION... /ISSUED 804 AM CDT MON JUL 6 2009/ UPDATE... .SOUNDING DISCUSSION... THE ATMOSPHERE IS VERY MOIST BUT RELATIVELY STABLE AT THIS POINT WITH A PRECIPITABLE WATER VALUE OF 2.13 INCHES AND A LIFTED INDEX VALUE OF 5.9. SPC HAS PUT THE CWA IN A SLIGHT RISK AREA WITH GUSTY WINDS BEING THE PRIMARY THREAT...SHOWERS ARE CURRENTLY AFFECTING THE NORTHERN PORTION OF THE CWA. THE ATMOSPHERE IS EXPECTED TO BECOME LESS STABLE AS DAYTIME HEATING OCCURS. WINDS ARE WESTERLY THROUGHOUT THE ATMOSPHERE PREV DISCUSSION... /ISSUED 326 AM CDT MON JUL 6 2009/ SYNOPSIS... WEAK LOW PRESSURE OVER NORTHERN MISSISSIPPI EARLY THIS MORNING WITH A TRAILING FRONT TO THE DFW METROPLEX. DYING MCS MOVING ACROSS SOUTHERN MISSISSIPPI. CLOUD COVER BLANKETS MOST OF THE AREA THIS MORNING...WITH TEMPERATURES REMAINING ABOVE NORMAL. SHORT TERM... RIDGE HAS BROKEN DOWN OVER THE AREA. WATER VAPOR LOOP SHOWS A STRING OF IMPULSES MOVING EAST-SOUTHEASTWARD TOWARD THE AREA. ONE IS MOVING JUST SOUTH OF JACKSON THIS MORNING...WITH THE NEXT NEAR THE DFW METROPLEX AND ANOTHER MOVING INTO THE TEXAS PANHANDLE. WITH A MOIST AIRMASS IN PLACE...THESE IMPULSES WILL AID IN THE DEVELOPMENT OF CONVECTION. EXPECT NEXT ROUND TO BE TRIGGERED MID TO LATE AFTERNOON...WITH ANOTHER ROUND POSSIBLE TUESDAY MORNING...AND A THIRD ROUND ON WEDNESDAY. DIURNAL HEATING WILL AID IN THE DEVELOPMENT AS WELL...WITH MOST SIGNIFICANT CONVECTION TO OCCUR IN THE AFTERNOON AND EVENING HOURS EACH DAY. CURRENTLY ENOUGH DRY AIR ALOFT TO PERMIT ISOLATED DOWNBURSTS...BUT WIDESPREAD SEVERE NOT ANTICIPATED. WILL CONTINUE WITH THE LIKELY POPS FOR TODAY...AND MAINLY CHANCE POPS BEYOND THAT. AS TIMING OF INDIVIDUAL IMPULSES GETS A LITTLE BETTER...ANOTHER PERIOD OF LIKELY POPS MAY END UP BEING NECESSARY AROUND WEDNESDAY. WITH CONSIDERABLY MORE CLOUD COVER THAN WHAT WE HAVE SEEN RECENTLY...AND BETTER AREAL COVERAGE OF PRECIPITATION...TEMPERATURES WILL RUN MUCH CLOSER TO NORMAL THAN HAS BEEN THE CASE FOR SEVERAL WEEKS. 35 LONG TERM... WEAKNESS IN UPPER PATTERN WILL CONTINUE THROUGH AT LEAST FRIDAY OR SATURDAY...WITH DIURNALLY BASED CONVECTION THE RULE FOR THOSE DAYS. MEDIUM RANGE MODELS NOW INDICATE RIDGE TO OUR WEST REBUILDING INTO THE AREA BY THE END OF THE WEEKEND. ECMWF WOULD INDICATE THAT THE RETURN OF THE RIDGE WILL BE TEMPORARY BEFORE RETREATING TO THE WEST AGAIN...WHILE THE GFS CENTERS IT MORE OVER THE AREA. THESE DIFFERENCES OCCUR BEYOND THE SCOPE OF THIS FORECAST. GENERALLY CHANCE POPS DURING THE DAY WITH LITTLE OR NO POPS AT NIGHT FOR THURSDAY THROUGH SATURDAY. WILL TRIM POPS SOMEWHAT FOR SUNDAY AND MONDAY...BUT NOT A DRY DAYTIME FORECAST QUITE YET. NEAR NORMAL TEMPERATURES WILL CONTINUE TIL ABOUT SUNDAY...THEN ABOVE NORMAL. SHOULD GFS SOLUTION VERIFY...TEMPS BY MIDWEEK NEXT WEEK COULD GET RATHER TOASTY AGAIN...ESPECIALLY IN AREAS THAT DO NOT GET SIGNIFICANT RAINFALL OVER THE NEXT FEW DAYS. 35 MARINE... OUR BNDRY IS ALREADY STALLING ACROSS THE REGION. THIS WILL KEEP WINDS OUT OF THE SW TO W THROUGH MID WEEK BEFORE ONSHORE FLOW RETURNS. WINDS HAVE BEEN IN EXERCISE CAUTION RANGE THROUGHOUT THE NIGHT OVER BOTH THE LAKES AND COASTAL WATERS AND IT LOOKS LIKE THEY WILL REMAIN IN THAT 15-20KT RANGE THROUGH TODAY. WITH THAT I HAVE EXTENDED THE EXERCISE CAUTION HEADLINE TILL 7PM AND ADDED THE TIDAL LAKES TO IT. SEAS HAVE ALSO INCREASED TO 3-4FT AND SHOULD RANGE FROM 3-5 THROUGH TONIGHT. WINDS WILL START TO SLACK OFF LATE TONIGHT/TOMORROW AS THE BNDRY BEGINS TO LOSE ITS IDENTITY CAUSING THE GRADIENT TO RELAX. AS FOR CONVECTION THINGS SHOULD REMAIN QUIET THROUGH THE MORNING BUT ANOTHER DISTURBANCE IS ON THE WAY AND THIS WILL LIKELY BRING SHRA AND TSRA OVER THE LAKES AND COASTAL WATERS LATE THIS AFTN/EARLY THIS EVN. THEN ANOTHER DISTURBANCE QUICKLY ON THE HEELS SHOULD BRING ANOTHER BAND OF CONVECTION DURING THE OVERNIGHT HRS. /CAB/ && .PRELIMINARY POINT TEMPS/POPS... MCB 78 70 86 70 / 100 50 50 30 BTR 88 76 89 72 / 70 70 60 40 MSY 90 78 89 76 / 70 70 70 40 GPT 85 75 87 74 / 80 60 70 40 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$