000 FXUS63 KABR 080232 AFDABR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 832 PM CST SAT NOV 7 2009 .UPDATE... CIGS THIS EVENING HAVE BEEN AOA 12KFT...AND ANY ECHOS ON RADAR ARE UNLIKELY TO BE REACHING THE GROUND. HOWEVER...SOME LIMITED INSTABILITY BETWEEN 500/600 HPA...ABOUT 40J/KG CAPE...HAS ALLOWED FOR SOME OBSERVED LIGHTNING SOUTH OF THE WHITE RIVER. THEREFORE...AMENDED FORECAST FOR MENTION OF SHOWERS ACROSS THE SOUTHERN TIER OF THE CWA. ALL OTHER FORECAST ELEMENTS REMAIN UNCHANGED. NO CHANGES TO AVIATION DISCUSSION BELOW. && .PREV DISCUSSION... .SHORT TERM...TONIGHT AND SUNDAY. ZONAL FLOW ALOFT KEEPING TEMPS MILD ACROSS THE REGION THIS AFTERNOON THROUGH SUNDAY. A WEAK SHORTWAVE WILL APPROACH THE FORECAST AREA LATER TONIGHT AND MOVE THROUGH SUNDAY. THIS SYSTEM LOOKS TO ONLY BRING MID/HIGH LEVEL CLOUDS AND A CHANCE OF SPRINKLES AS IT MOVES ACROSS THE REGION. MADE FEW CHANGES TO GOING FORECAST. COOLER AIR WILL WORK IN BEHIND SYSTEM ON SUNDAY FOR SOMEWHAT COOLER TEMPS...BUT STILL VERY MILD. GFS/NAM MOSTLY DRY WITH SYSTEM ON SUNDAY. MID-TERM...SUNDAY NIGHT THROUGH WEDNESDAY NIGHT BASED MORE OFF THE 12Z GFS/NAM SOLUTIONS THAN THE 00Z ECMWF SOLUTION...SHOULD BE A RELATIVELY QUIET PERIOD WITH HIGH PRESSURE /EITHER ALOFT OR AT THE SURFACE/ IN PLACE FOR MOST OF THE PERIOD. IT APPEARS THAT THERE WILL BE A WEAK COLD FRONTAL PASSAGE WORKING SEWD THROUGH THE CWA SUNDAY NIGHT. HOWEVER...THE CAA FOLLOWING BEHIND THE COLD FRONTAL PASSAGE SUNDAY NIGHT INTO MONDAY APPEARS TO BE RATHER SHORT-LIVED...AS BY TUESDAY RETURN FLOW STARTS TO SET BACK UP ACROSS THE CWA...STARTING OUT WEST FIRST...AND THEN SPREADING FURTHER EAST TUESDAY NIGHT THROUGH WEDNESDAY. WITH SOUTHERLY 925HPA WINDS AROUND 25 TO 30 KNOTS AND 850HPA WINDS OF 30 TO 35 KNOTS...TUESDAY AND TUESDAY NIGHT SHOULD END UP BEING A RATHER BREEZY/WINDY PERIOD OF THE FORECAST. OVERALL...IT STILL APPEARS AS THOUGH PRETTY MUCH EVERY FORECAST PERIOD BETWEEN SUNDAY NIGHT AND WEDNESDAY NIGHT WILL SEE TEMPERATURES AT OR ABOVE NORMAL. .LONG TERM...THURSDAY THROUGH SATURDAY GFS AND ECMWF SHOW SOME DISAGREEMENT WITH SYSTEM SET TO MOVE THROUGH FRIDAY INTO SATURDAY. IN ADDITION...GFS ENSEMBLE MEMBERS DIVERGE QUITE A BIT BY THIS TIME AS WELL. THE MAIN PROBLEM WITH MODEL UNCERTAINTY IS THE LOW MOVING IN FROM THE PACIFIC NORTHWEST. GFS SEEMS FASTER WHILE ECMWF SEEMS DEEPER. THEREFORE...WENT WITH SLIGHT POPS THURSDAY THROUGH MUCH OF SATURDAY. AS MODELS GET A BETTER HANDLE ON THE SYSTEM OVER THE NEXT COUPLE DAYS...FORECAST CONFIDENCE SHOULD INCREASE. && .AVIATION... MID AND HIGH LEVEL CLOUDS WILL MOVE ACROSS THE REGION OVERNIGHT. HOWEVER EXPECT VFR CONDITIONS TO PREVAIL WITH ONLY A FEW LIGHT SHOWERS OR SPRINKLES POSSIBLE LATE TONIGHT OR EARLY SUNDAY MAINLY NORTH. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...CONNELLY SHORT TERM...SCARLETT LONG TERM...DORN AVIATION...CONNELLY WEATHER.GOV/ABERDEEN