RSS FeedsIssued by NWS Aberdeen, SD
000 FXUS63 KABR 240937 AFDABR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 337 AM CST TUE NOV 24 2009 .SHORT TERM...THROUGH THURSDAY MAIN FOCUS IS ON NORTHWEST FLOW CLIPPER SYSTEM. THE QUICK MOVING SYSTEM PRESENTS WITH FAVORABLE JET COUPLING AND MID LEVEL ISENTROPIC ASCENT...SUGGEST POTENTIAL FOR BRIEF MODERATE INTENSITY PRECIPITATION LATE TUESDAY NIGHT INTO WEDNESDAY AM. PROFILE TEMPERATURES AND/OR WET BULB EFFECT SUPPORTIVE OF SNOW AS MAIN P TYPE. BEST PROBABILITY LIES IN THE EAST WHERE STRONGEST FORCING MEETS BETTER MOISTURE...WHILE THE WEST HAS STRONGEST FORCING DISLOCATED FROM DENDRITE GROWTH ZONE...ALL OVERTOP A DRY LAYER OF 15KFT...MORE FAVORABLE FOR FLURRIES. ONCE WARM ADVECTION/ISENTROPIC FORCING AREA PASSES EAST...GUIDANCE BRINGS A SECOND WAVE OF MID LEVEL ASCENT ASSOCIATED WITH THE CIRCULATION CENTER ACROSS THE EASTERN CWA DURING THE DAY WEDNESDAY. WILL INCREASE OVERALL POPS BUT DURATION OF EVENT DICTATES KEEPING ACCUMULATIONS LIGHT. HIGH PRESSURE BUILDING BEHIND SHORTWAVE LEADS TO COLD ADVECTION AND WIND DIRECTION PHASED UP TO A 90KT JET...ONLY CAVEAT IS THAT PRESSURE RISES ARE ONLY ON THE ORDER OF 3MB/6HRS...SO WINDS MORE THAN LIKELY TO REMAIN SUB ADVISORY. WARM ADVECTION BEGINS TO REESTABLISH LATE THURSDAY. .LONG TERM...THURSDAY NIGHT THROUGH MONDAY THE 00Z MODELS...ESPECIALLY THE ECMWF...REMAIN FAIRLY STABLE WITH THE LONG WAVE PATTERN AND ITS EVOLUTION. MID LEVEL RIDGING OVER THE PLAINS EARLY IN THE PERIOD SHOULD BE REPLACED BY POSITIVE TILT TROFFING. ALL MODELS SHOW SOME DEGREE OF SPLIT IN THE FLOW AS THAT TROF MOVES EAST INTO THE WESTERN/CENTRAL CONUS...WITH THE GFS SHOWING ITS TYPICAL FAST BIAS. SO...IT STILL APPEARS AS IF THE FIRST PART OF THE HOLIDAY WEEKEND WILL BE DRY...WITH SOME CHANCE OF LIGHT PCPN TOWARD THE END OF THE WEEKEND AS THE UPPER TROF DRAWS CLOSER. MEANWHILE...TEMPERATURES SHOULD BE NEAR TO MAYBE A COUPLE DEGREES ABOVE NORMAL THROUGH THE PERIOD...WITH THE STABLE ECMWF BEING THE WARMEST OF ALL DETERMINISTIC MODEL RUNS. && .AVIATION... IFR/MVFR CIGS/VSBYS WILL PREVAIL AT KATY INTO THE MID MORNING HOURS BEFORE FINALLY BREAKING UP. THE LOW CLOUDS AND FOG COULD BACK INTO KABR FOR A FAIRLY SHORT TERM...BUT CONFIDENCE IN THIS HAPPENING IS LOW. KPIR/KMBG SHOULD REMAIN VFR THROUGH TNT. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...CONNELLY LONG TERM...TDK AVIATION...TDK WEATHER.GOV/ABERDEEN
