447 FXUS63 KUNR 110921 AFDUNR AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 321 AM MDT SUN OCT 11 2015 .SHORT TERM...TODAY THROUGH MONDAY NIGHT ISSUED AT 241 AM MDT SUN OCT 11 2015 UPPER LEVEL ANALYSIS HAS BROAD RIDGE ACROSS THE CENTRAL CONUS WITH SHORTWAVE TROF CROSSING THE NORTHERN ROCKIES. SKIES ARE MAINLY CLEAR ACROSS THE NORTHERN PLAINS. AT THE SURFACE...WEAK HIGH PRESSURE IS IN PLACE WITH WESTERLY BOUNDARY LAYER FLOW KEEPING TEMPERATURES VERY MILD...MAINLY IN THE 50S AND 60S. TODAY...UPPER RIDGE AXIS WILL SHIFT EAST OF THE REGION AS UPPER SHORTWAVE QUICKLY MOVES INTO THE NORTHERN PLAINS. A STRONG COLD FRONT WILL CROSS THE AREA TODAY...CLEARING SOUTH CENTRAL SD BY MID TO LATE AFTERNOON. NORTHWEST WINDS WILL DEVELOP BEHIND THE FRONT AND BECOMING STRONG ESPECIALLY ACROSS NORTHWEST SD. LOOKS LIKE WINDS WILL REACH WELL INTO ADVISORY CRITERIA OF 25 TO 35 MPH ACROSS MUCH OF THE WESTERN SD PLAINS EXCEPT FAR SOUTHWEST SD AND SOUTH CENTRAL SD. WINDS AROUND 40 MPH WILL BE POSSIBLE ACROSS FAR NORTHWEST SD...WHERE A HIGH WIND WARNING WILL BE IN PLACE. WINDS ACROSS MUCH OF THE AREA WILL SUBSIDE SHORTLY AFTER SUNSET...BUT THE PRESSURE GRADIENT WILL REMAIN TIGHT ACROSS FAR NORTHWEST SD WHERE THE HIGH WIND WARNING WILL EXTEND INTO TONIGHT. MAXIMUM TEMPERATURES WILL BE A LITTLE TRICKY GIVEN THE TIMING OF THE COLD FRONT...BUT GENERALLY BEHIND THE FRONT ACROSS NORTHEAST WY AND NORTHWEST SD...TEMPS WILL REACH THE LOW 70S...WHILE SOUTH CENTRAL SD WILL REACH THE UPPER 80S BEFORE THE FRONT MOVES THROUGH THERE. COOLER AIR WILL MOVE INTO THE AREA TONIGHT AS SURFACE HIGH PRESSURE MOVES INTO THE AREA. LOW TEMPERATURES WILL FALL INTO THE 30S AND 40S TONIGHT. THE MILDEST TEMPERATURES WILL BE FOUND IN AREAS WHERE THE WIND REMAINS BREEZY OVERNIGHT. WITH THE VERY WINDY CONDITIONS AND THE VERY DRY AIR MOVING IN...CRITICAL FIRE WEATHER CONDITIONS WILL BE IN PLACE ACROSS THE ENTIRE AREA FROM LATE MORNING THROUGH EARLY EVENING. A FIRE WEATHER DISCUSSION IS INCLUDED BELOW. MONDAY...QUICK MOVING UPPER TROF SHIFTS EAST WITH RIDGING BUILDING INTO THE AREA AGAIN. HIGH PRESSURE WILL REMAIN ACROSS WESTERN AREAS WITH A DECENT PRESSURE GRADIENT REMAINING ACROSS NORTHWESTERN SOUTH DAKOTA. THIS WILL KEEP WINDS BREEZY ACROSS NORTHWEST SOUTH DAKOTA THROUGH MUCH OF THE DAY. HIGH TEMPERATURES WILL BE MORE SEASONABLE...IN THE 60S. WINDS WILL SUBSIDE BY EVENING...WITH CLEAR SKIES EXPECTED. LOW TEMPERATURES WILL FALL INTO THE UPPER 30S TO MID 40S. .LONG TERM...TUESDAY THROUGH SATURDAY ISSUED AT 241 AM MDT SUN OCT 11 2015 AN UPPER LEVEL RIDGE BUILDING OVER THE WESTERN CONUS WILL LEAD TO DRY AND MILD WEATHER INTO NEXT WEEKEND. HIGH TEMPERATURES WILL BE 5 TO 10 DEGREES WARMER THAN AVERAGE FOR THIS TIME OF YEAR. && .AVIATION...FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING ISSUED AT 241 AM MDT SUN OCT 11 2015 VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT. VERY GUSTY NORTHWEST WINDS ARE EXPECTED TODAY BEHIND A STRONG COLD FRONT. && .FIRE WEATHER... ISSUED AT 241 AM MDT SUN OCT 11 2015 A STRONG COLD FRONT WILL MOVE THROUGH THE AREA TODAY...FOLLOWED BY GUSTY NORTHWEST WINDS OF 25 TO 40 MPH. GUSTS TO AROUND 55 MPH ARE POSSIBLE THIS AFTERNOON OVER PARTS OF WESTERN SOUTH DAKOTA. DRY AIR WILL MOVE IN BEHIND THE FRONT...PRODUCING LOW RELATIVE HUMIDITY READINGS OF 15 TO 25 PERCENT. THE COMBINATION OF LOW RELATIVE HUMIDITY AND GUSTY WINDS WILL PRODUCE CRITICAL FIRE WEATHER CONDITIONS THIS AFTERNOON INTO EARLY EVENING. THEREFORE A RED FLAG WARNING WILL BE IN PLACE FROM LATE THIS MORNING THROUGH EARLY THIS EVENING FOR ALL FIRE WEATHER ZONES. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...RED FLAG WARNING FROM 10 AM THIS MORNING TO 7 PM MDT THIS EVENING FOR SDZ260>266. WIND ADVISORY FROM 10 AM MDT /11 AM CDT/ THIS MORNING TO 7 PM MDT /8 PM CDT/ THIS EVENING FOR SDZ012>014-025-026-031-032- 043-046-072-073. HIGH WIND WARNING FROM 10 AM THIS MORNING TO 3 AM MDT MONDAY FOR SDZ001-002. WY...RED FLAG WARNING FROM 10 AM THIS MORNING TO 7 PM MDT THIS EVENING FOR WYZ259-297>299. && $$ SHORT TERM...15 LONG TERM...JOHNSON AVIATION...JOHNSON FIRE WEATHER...15