000 FXUS64 KHUN 301136 AAA AFDHUN AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE HUNTSVILLE AL 635 AM CDT SAT AUG 30 2008 .UPDATE...FOR 12Z TAFS/AVIATION DISCUSSION && .AVIATION...PATCHY FOG THIS MORNING HAS NOT BEEN AS DENSE OR WIDESPREAD AS THE PREVIOUS FEW MORNING...MAINLY DUE TO SOME DRY AIR INTRUSION ON THE BACKSIDE OF THE SWD MOVING SFC FRONT. ANY FOG THAT IS AROUND SHOULD LIFT SHORTLY AFTER 8 AM. OTHERWISE...VFR CONDITIONS SHOULD PREVAIL THROUGH TODAY AND INTO TONIGHT. ISOLATED TSTMS THIS AFTERNOON MAY BRIEFLY LOWER CRITERIA TO MVFR FOR TERMINALS NEAR ANY CONVECTION...BUT COVERAGE IS XPCTED TO BE LOW ENOUGH TO NOT WARRANT ANY TEMPO/PROB30 GROUPS IN THE 12Z TAF PACKAGE. && .DISCUSSION... QUIET WEATHER PREVAILED ACROSS THIS PART OF THE TENNESSEE VALLEY. SHOWER ACTIVITY THAT OCCURRED DURING FRIDAY AND CURRENT OVERNIGHT COOLING HAS HELPED PATCHY FOG DEVELOP ACROSS THE AREA. FOG COVERAGE IS EVEN MORE SPOTTY THAN THE PAST FEW DAYS...HOWEVER SOME OF IT WAS LOCALLY DENSE. A COLD FRONT WAS OVER PARTS OF THE AREA AS OF THIS WRITING...EXTENDING ROUGHLY FROM AROUND THE MUSCLE SHOALS AREA AND TULLAHOMA AND NNE ALONG THE CUMBERLAND PLATEAU TO EASTERN OHIO. UPPER RIDGING WAS CENTERED OVER THE SW CONUS WITH A MORE ACTIVE WESTERLY FLOW FROM THE PACIFIC NW TO QUEBEC. THE INFRARED SATELLITE VIEW NOTED AN AREA OF THIN CIRRUS OVER THE REGION...WITH MID LEVEL CLOUDS GENERALLY DISSIPATING AS THEY MOVE TO THE SOUTH. FOG WAS NOTED FROM SW OF CHATTANOOGA TO SCOTTSBORO. WEATHER IN THE TROPICS IS BECOMING MORE ACTIVITY...WITH HURRICANE GUSTAV CHURNING UP THE CARIBBEAN NORTH OF GRAND CAYMAN. IT WAS SHOWING A VISIBLE EYE VIA THE INFRARED SATELLITE VIEW...A SIGN IT IS STRENGTHENING FURTHER. TROPICAL STORM HANNA CONTINUES IT DEVELOPMENT ABOUT 400 MILES EAST OF THE BAHAMAS. FOR THE SHORTER TERM...LIFT PROVIDED BY A FRONTAL BOUNDARY LURKING OVER THE REGION ALONG WITH PLENTY OF MOISTURE AND INSTABILITY FROM DAYTIME HEATING WILL RESULT IN A SLIGHT CHANCE OF SHOWERS AND T-STORMS THIS AFTERNOON. HAVE DECREASED ODDS OF MEASURABLE RAINS TO ISOLATED POPS FOR THE EVENING. WARM TO HOT HIGH TEMPERATURES ARE ONCE AGAIN EXPECTED...WITH HIGHS WARMING INTO THE UPPER 80S AND LOWER 90S. MORE OF THE SAME IS EXPECTED FOR THE LAST DAY OF AUGUST OR SUNDAY...WITH ISOLATED SHOWERS/THUNDERSTORMS DURING THE AFTERNOON. OUR ATTENTION BECOMES MORE FOCUSED ON THE WHEN AND WHERE HURRICANE GUSTAV MAKES LANDFALL. THE 00Z NAM/GFS AND 12Z ECMWF WERE IN RATHER GOOD AGREEMENT WITH THE TIMING OF THE STORM NEARING LANDFALL TUESDAY MORNING. THE NAM AND ITS DGEX EXTENDED RUN DURING TUESDAY MORNING TAKE GUSTAV AND BY THURSDAY MORNING MERGE IT WITH HANNA OVER THE FLORIDA KEYS...A QUITE UNLIKELY SOLUTION. THE 00Z ECMWF HAS SHIFTED THE PATH A TAD MORE TO THE WEST...AND HAS SPED UP THE TIMING BY ABOUT 12 HRS. IN THE GFS OR ECMWF VIEW...DIRECT EFFECTS FROM GUSTAV WILL BE MINIMAL FOR THIS AREA. HOWEVER ITS EXTENSIVE CLOUD SHIELD AND THIS AREA BEING ON THE EAST SIDE OF ITS CIRCULATION IS GOOD ENOUGH TO KEEP A LOW CHANCE OF MAINLY SHOWERS AND EMBEDDED T-STORMS IN THE FORECAST. THE EVENTUAL PATH OF HANNA IS EVEN MORE UNCERTAIN. THE PREVIOUS 12Z ECMWF MOVED THIS STORM FROM FAR WESTERN FLORIDA ACROSS THE TENNESSEE VALLEY AND FURTHER NORTHWARD LATE NEXT WEEK...SIMILAR TO THE 18Z GFS. THE 00Z GFS WAS FAR MORE EASTWARD IN ITS PREDICTED PATH OF HANNA...WITH THE 00Z ECMWF FOLLOWING SUIT BY NOT QUITE AS FAR. HAVE LEFT A SLIGHT CHANCE OF SHOWERS IN THE FORECAST FOR MY LAST PERIOD FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... HUNTSVILLE 91 68 92 70 89 / 20 10 10 10 30 SHOALS 92 69 92 70 89 / 20 10 10 10 30 CULLMAN 93 70 93 70 89 / 20 10 10 10 30 FAYETTEVILLE 90 69 89 69 87 / 20 10 10 10 30 ALBERTVILLE 92 70 92 72 89 / 20 10 10 10 30 FORT PAYNE 89 67 90 68 87 / 20 10 10 10 30 && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ AVIATION: 09 DISCUSSION: RSB