000 FXUS63 KABR 231716 AAA AFDABR AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE ABERDEEN SD 1116 AM CST MON NOV 23 2009 .UPDATE... ONLY MAJOR UPDATE TO THE FORECAST THIS MORNING WAS TO ADD IN THE MENTION OF FOG ACROSS A GOOD PORTION OF THE AREA. VSBYS VARYING FROM 1/2 MILE TO 5 MILES ACROSS ALL BUT THE FAR WESTERN CWA...SO FEEL IT WARRANTS A MENTION. NO CHANGES MADE TO WINDS OR TEMPERATURES. NEW AVIATION DISCUSSION BELOW. && .PREV DISCUSSION... .SHORT TERM...TODAY THROUGH WEDNESDAY CURRENT WATER VAPOR IMAGERY AND RUC ANALYSIS SHOWS MAIN 500MB TROUGH OVER THE NORTHERN ROCKIES. BROAD SURFACE LOW EXISTS ACROSS EASTERN COLORADO AND THIS LOW WILL DEEPEN TODAY AS UPPER TROUGH SHIFTS EAST INTO THE PLAINS. RUC ALSO SHOWING A LEAD 700MB WAVE MOVING NORTH ACROSS THE CWA WITH THE BEST LIFT ACROSS THE EASTERN CWA. SCT LIGHT SHOWERS HAVE BEEN ONGOING OVER THE PAST COUPLE HOURS EAST OF THE JAMES RIVER. FOR TODAY...INVERTED SFC TROUGH WILL BECOME BETTER DEFINED ALONG THE SD/MN BORDER WITH A WAVE OF ENERGY RIDING ALONG THIS TROUGH. WILL MAINTAIN 30-50 POPS ACROSS THE NORTHEASTERN CWA FOR TODAY. MAIN UPPER/SFC LOW WILL MOVE EAST ACROSS THE CENTRAL PLAINS TODAY THROUGH TUESDAY MORNING AND MODELS HAVE SHIFTED THESE FEATURES SOUTH A TAD. ONLY EXPECTING PRECIP TODAY NEAR THE INVERTED SFC TROUGH/WEAK UPPER WAVE COMBO...WHILE ANY PRECIP ASSOCIATED WITH THE MAIN SFC LOW WILL STAY SOUTH OF THE REGION. LATE TONIGHT INTO TUESDAY MORNING THERE IS A BIT OF UNCERTAINTY REGARDING IF/WHEN SFC LOW TAKES A JOG TO THE NORTHEAST AND POSSIBLY SPREAD PRECIP INTO THE FAR SOUTHEASTERN CWA. WILL KEEP CHANCE POPS ACROSS THE EASTERN CWA AND HAVE NOT GONE LIKELY AT THIS TIME. THERMAL PROFILES STILL SUPPORTING A MOSTLY RAIN EVENT. COULD BE A RAIN/SNOW MIX ALONG THE WESTERN EDGE OF PRECIP SHIELD LATE TONIGHT INTO TUESDAY MORNING BUT DO NOT EXPECT MUCH IN THE WAY OF ACCUMS. NEXT SHORTWAVE DROPS SOUTHEAST OVER THE AREA LATE TUESDAY NIGHT THROUGH WEDNESDAY. FAIRLY WOUND UP 500MB LOW LOOKS TO MOVE THROUGH WITH FAIRLY STEEP LAPSE RATES DUE TO THE COLD AIR ALOFT. POSSIBILITY EXISTS FOR ISO/SCT LIGHT SNOW SHOWERS AS THIS WAVE MOVES THROUGH AND WILL STICK WITH THE 20/30 POPS. COULD EVEN BE A LIGHT DUSTING OF SNOW ACROSS THE NORTHEASTERN CWA. WEDNESDAY WILL ALSO BE BREEZY/WINDY ACROSS THE ENTIRE CWA AS THIS QUICK MOVING WAVE MOVES THROUGH. .LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY THE 00Z MODELS MAINTAIN A PROGRESSIVE MID LEVEL FLOW SITUATION THROUGH THE LONG TERM...ALONG WITH OCCASIONAL SPLIT FLOW CHARACTERISTICS. MEANWHILE THE MAJORITY OF THE FORECAST PERIOD SHOULD BE DRY AS MID LEVEL RIDGING ASSERTS ITSELF ACROSS THE NORTHERN PLAINS THROUGH FRIDAY. AFTERWARD AN APPROACHING MID LEVEL TROF FOR THE LATTER PART OF THE WEEKEND COULD BRING SOME LIGHT PCPN...BUT FOR NOW CHANCES LOOK PRETTY MINIMAL BASED ON MODEL SOUNDINGS...THUS WILL MAINTAIN DRY FORECAST. TEMPERATURES SHOULD AVERAGE NEAR TO ABOVE NORMAL FOR MOST OF THE TIME PERIOD. AND BASED ON LATEST ECMWF/GFS PROGS...DID DECIDE TO BUMP UP TEMPS A TOUCH AHEAD OF ADVANCING FRONT NEXT WEEKEND. OTHERWISE NO MAJOR CHANGES WERE MADE TO THE FORECAST. && .AVIATION... 12Z TAF UPDATE FOR KABR...KATY...KPIR AND KMBG UNTIL THE AREA OF LOW PRESSURE OVER NORTHEASTERN WYOMING WORKS SOUTHEAST AWAY FROM THIS REGION...WILL BE DEALING WITH SOME LESS THAN IDEAL FLYING WEATHER CONDITIONS ACROSS THE FORECAST AREA TODAY...POSSIBLY INTO THIS EVENING. ONE BATCH OF LIGHT RAINFALL HAS LIFTED NORTHWARD OUT OF THIS AREA...WHILE ANOTHER AREA OF LIGHT RAIN IS TRYING TO ORGANIZE ACROSS NEBRASKA AND SOUTHERN SOUTH DAKOTA. MVFR TO IFR FLYING WEATHER CONDITIONS ARE OCCURRING AT EVERY TERMINAL THIS MORNING BUT KMBG. THEY ARE PROBABLY TOO FAR NORTH AND WEST OF ALL THIS LOW LEVEL MOISTURE TO JOIN THE FREY...AND WILL LIKELY REMAIN VFR OVER THE NEXT 24 HOURS. IT IS A DIFFERENT STORY ELSEWHERE AS LOW LEVEL MOISTURE HAS REACHED THE KPIR AND KABR TERMINALS WHERE CIGS AND VSBYS ARE DROPPING LIKE A ROCK. FLIGHT CATEGORY IS TEETERING ON THE BORDER OF VLIFR AND LIFR THERE...AND NOT EXPECTING CONDITIONS TO BEGIN SHOWING IMPROVEMENT AT THESE TWO TERMINALS UNTIL MUCH LATER THIS AFTERNOON. IFR CIG/VSBY CONDITIONS HAVE IMPROVED AT KATY THIS MORNING TO MVFR IN LIGHT FOG...AS AN AREA OF CLEARING HAS MOVED OVER THAT TERMINAL. HOWEVER...IFR CONDITIONS FROM LOW CIGS/FOG ARE EXPECTED TO RETURN TO THE KATY TERMINAL WITHIN THE NEXT FEW HOURS...AND STICK AROUND THROUGH AT LEAST THIS EVENING BEFORE WINDS SWITCH AROUND TO THE NORTHWEST AND IMPROVEMENT IN FLIGHT CATEGORY LATER TONIGHT CAN TAKE HOLD THERE. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...PARKIN SHORT TERM...TMT LONG TERM...TDK AVIATION...DORN WEATHER.GOV/ABERDEEN