191 FXUS63 KUNR 310518 AFDUNR AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 1118 PM MDT FRI OCT 30 2015 .SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT ISSUED AT 233 PM MDT FRI OCT 30 2015 UPPER LEVEL ANALYSIS HAS HIGH AMPLITUDE TROF SHIFTING EAST OF THE AREA WITH WESTERN RIDGE BUILDING INTO THE ROCKIES AND NORTHERN PLAINS. SKIES ARE MOSTLY SUNNY ACROSS THE FORECAST AREA WITH HIGH CLOUDS STREAMING IN ACROSS MONTANA. AT THE SURFACE...HIGH PRESSURE RESIDES ACROSS THE GREAT BASIN WITH LEE TROF ACROSS CENTRAL MONTANA AND WYOMING. BOUNDARY LAYER WINDS ARE OUT OF THE WEST WITH 3PM TEMPERATURES IN THE 50S TO AROUND 60 DEGREES. TONIGHT...CLOUD COVER WILL BE ON THE INCREASE OVERNIGHT AS MID AND HIGH LEVEL CLOUDS SPILL OVER THE WESTERN RIDGE. WINDS WILL PREDOMINATELY BE OUT OF THE WEST WITH TEMPERATURES FALLING INTO THE 30S TO AROUND 40 DEGREES. SATURDAY...WARMER AIR WILL CONTINUE TO BUILD INTO THE AREA...WITH HIGHS IN THE 60S ACROSS THE PLAINS...50S OVER THE HIGHER BLACK HILLS. BRISK WEST TO NORTHWEST WINDS WILL DEVELOP INTO THE AFTERNOON...ESPECIALLY ACROSS NORTHWEST SD...AS SOME STRONGER WINDS ALOFT MIX DOWN THROUGH THE BOUNDARY LAYER. SKIES WILL BE PARTLY CLOUDY IN MOST AREAS...WITH THE MOST SUN EXPECTED SOUTH AND EAST OF THE BLACK HILLS. HALLOWEEN EVENING LOOKS RATHER PLEASANT WITH WINDS QUICKLY DIMINISHING AROUND SUNSET AND TEMPS DROPPING FROM THE 50S TO THE 40S THROUGH THE EVENING. CLOUD COVER WILL INCREASE AGAIN...MAINLY ACROSS THE NORTH...AS A WEAK WEATHER SYSTEM SLIDES ACROSS NORTH DAKOTA. LOW TEMPERATURES SATURDAY NIGHT WILL FALL INTO THE 30S TO LOWER 40S. .LONG TERM...SUNDAY THROUGH FRIDAY ISSUED AT 233 PM MDT FRI OCT 30 2015 WESTERLY DOWNSLOPE FLOW WILL CREATE MILD FALL WEATHER FOR SUNDAY WITH HIGH TEMPERATURES RANGING FROM 5-15F WARMER THAN THE AVERAGE FOR THIS TIME OF YEAR. AN UPPER LEVEL TROUGH WILL DEEPEN OVER THE WESTERN CONUS ON MONDAY AND TUESDAY CREATING SOUTHWESTERLY FLOW ALOFT OVER THE NORTHERN PLAIN. A FEW SHORTWAVES WILL CROSS THE FORECAST AREA CREATING CHANCES FOR PRECIPITATION. TEMPERATURES MAY BE COLD ENOUGH AT NIGHT FOR SOME SNOW TO MIX IN WITH THE RAIN IN SOME LOCATIONS. CONFIDENCE REMAINS LOW WITH THE EVENTUAL EVOLUTION OF THE UPPER TROUGH AS IT MOVES EAST DURING THE SECOND HALF OF NEXT WEEK. GFS CONTINUES TO BRING A MORE DISTINCT UPPER LOW ACROSS THE CENTRAL PLAINS WHILE THE ECMWF INDICATES A TREND TOWARD SPLIT FLOW WITH SOME ENERGY MOVING INTO THE DAKOTAS AND ANOTHER FROM THE CENTRAL PLAINS INTO THE MIDWEST. MAY BE BE SOME -RASN AROUND AS COLDER AIR SINKS IN BEHIND A SERIES OF COLD FRONTS BUT MODEL SOLUTIONS REMAIN INCONSISTENT IN HANDLING THE TRACK...STRENGTH AND TIMING OF THE UPPER TROUGH/LOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1115 PM MDT FRI OCT 30 2015 A POCKET OF MVFR/IFR CONDS CAN BE EXPECTED THROUGH EARLY MORNING AROUND KICR AND SE. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH SATURDAY MOST PLACES. A TROUGH WILL PROGRESS THROUGH THE AREA EARLY SAT MORNING...WITH GUSTY NW WINDS EXPECTED BEHIND THE TROUGH. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...15 LONG TERM...10 AVIATION...JC