000 FXUS63 KILX 300729 AFDILX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 229 AM CDT SAT AUG 30 2008 .DISCUSSION... ISSUED 229 AM CDT SAT AUG 30 2008 EARLY MORNING SFC MAP SHOWED HIGH PRESSURE STRETCHING FROM THE GREAT LAKES BACK INTO THE CENTRAL PLAINS. CLEAR SKIES...CALM WINDS AND DEWPOINTS IN THE MID 50S WERE COMMON UNDER THIS RIDGE. ALOFT...A BROAD FLAT RIDGE EXTENDED WEST-EAST ACROSS THE SOUTHERN HALF OF THE U.S. WITH THE MAIN BELT OF WESTERLIES ALONG THE CANADIAN BORDER. QUIET WEATHER WILL CONTINUE TO DOMINATE FOR THE NEXT SEVERAL DAYS...WITH THE NEXT LOW RAIN CHANCE COMING AROUND MID-WEEK WITH A COLD FRONT. SHORT TERM...SATURDAY THROUGH SUNDAY HIGH PRESSURE RIDGE WILL DOMINATE THE AREA THROUGH THE WEEKEND. THIS WILL BRING A CONTINUATION OF SEASONABLE TEMPERATURES...LIGHT WINDS...AND CLEAR SKIES. FCST SOUNDINGS...MEAN LAYER RH PROGS...AND CU RULE ALL SUGGEST MOTHER NATURE WILL HAVE A HARD TIME GENERATING ANY CLOUDS INTO SUNDAY AS WE REMAIN UNDER A DRY AND SUBSIDING AIRMASS. TEMPERATURES MAY WARM A DEGREE OR TWO EACH DAY WITH HIGHS GENERALLY IN THE MID TO UPPER 80S AND LOWS IN THE MID 50S TO LOWER 60S. LONG TERM...MONDAY THROUGH FRIDAY THE SFC RIDGE WILL SHIFT EAST INTO THE APPALACHIANS BY MONDAY NIGHT...ALLOWING SOUTHERLY FLOW TO DEVELOP ACROSS THE REGION. THIS WILL BRING SLIGHTLY WARMER AND MORE HUMID AIR IN...WITH HIGHS REACHING AROUND 90/LOWER 90S FOR MON/TUE. THE MID LEVEL RIDGE WILL ALSO PUSH OFF TO THE EAST IN RESPONSE TO A DEVELOPING TROUGH OVER THE ROCKIES. ON THE LEADING EDGE OF THIS TROUGH...A SFC LOW AND COLD FRONT ARE EXPECTED TO DEVELOP ACROSS THE PLAINS EARLY TUESDAY. THE MAIN SHORTWAVE WITH THIS SYSTEM LOOKS TO PASS WELL NORTH...THROUGH THE UPPER LAKES...AS THE MID LEVEL RIDGE HOLDS STRONG TO OUR EAST. THE TRAILING COLD FRONT IS PROGGED TO MOVE THROUGH ON WEDNESDAY...IN A WEAKENING FASHION AS IT HEADS INTO THE RIDGE...ACCORDING TO THE GFS. FOR NOW HAVE ONLY SLGT CHC POPS IN DUE TO THE WEAK APPEARANCE OF THE FRONT AND TIMING ISSUES. LATEST ECMWF WASHES THE FRONT OUT BEFORE IT REACHES THE AREA. THE MAIN WEATHER FEATURE IN THE MID TO LATE WEEK PERIOD WILL BE HOW/IF THE REMNANTS OF GUSTAV ARE DRAWN NORTH INTO THE WESTERLIES. MAJOR DIFFERENCES BETWEEN MEDIUM RANGE MODELS HANDLING THIS FEATURE...WITH GFS STALLING SYSTEM NEAR TX/LA...WHILE ECMWF DRIVES IT NNE INTO CENTRAL MO BY THU AM WITH HEAVY RAIN AFFECTING THE WESTERN HALF OF THE CWA. MEANWHILE HANNAH APPROACHES THE SE U.S. BY THE END OF THE WEEK FURTHER COMPLICATING THE PATTERN. WITH THESE POTENTIALLY STRONG TROPICAL SYSTEMS AFFECTING THE FLOW ACROSS THE COUNTRY...LATE PERIOD FORECAST CONFIDENCE IS LOW...AND NO CHANGES HAVE BEEN MADE TO THE FORECAST BEYOND WED. SCHAFFER && .AVIATION... ISSUED 1135 PM CDT FRI AUG 29 2008...FOR THE 06Z TAFS FORECAST SOUNDINGS INDICATE PLENTY OF DRY AIR THROUGH ALL LAYERS OF THE ATMOSPHERE WILL BE IN PLACE OVER THE NEXT 24 HOURS...AT LEAST. THE RIDGE AXIS WILL MAINTAIN JUST NORTH AND WEST OF OUR CWA...SO THE EXPECTED WIND FLOW SHOULD REMAIN EAST TO SE. WILL NOT PUT ANY CLOUDS IN THE FORECAST...AS RH LEVELS REMAIN LESS THAN 40% AT ALL LEVELS. CU RULES ALSO SHOWING CLEAR SKIES. FOG NOT EXPECTED TONIGHT EITHER. THAT SHOULD REMAIN MUCH FARTHER SOUTH CLOSER TO THE HIGHER DEWPOINTS AND THE STALLED FRONTAL BOUNDARY IN S MO/FAR S IL/KY. SHIMON && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$