749 FXUS63 KUNR 301958 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 1258 PM MST Tue Dec 30 2025 .KEY MESSAGES... - Mild and dry conditions will persist through the weekend && .DISCUSSION...(This Evening Through Tuesday) Issued at 1236 PM MST Tue Dec 30 2025 20Z upper level analysis has a cutoff low off the southern California coast, broad ridge over the western CONUS, and a broad trof across the eastern CONUS. Fast northwest flow is in place across the Northern Plains, with mostly clear skies and high clouds streaming through at times. At the surface, broad high pressure is in place across much of the western United States, with the forecast area on the eastern periphery. Temperatures across the forecast area at 2pm are in the 40s to lower 50s, with breezy northwest winds across the SD plains. Western upper ridge will remain nearly stationary through the end of the week. Mild and dry conditions will persist for the next several days, with breezy west to northwest winds at times. Temperatures will range from the upper 30s in far northwest and central SD areas, to the mid 50s further south and west. Weak baroclinic zone will wiggle a little further west on Friday, allowing the cooler 30s to cover more of the western SD plains, with 40s elsewhere. As the western upper ridge shifts into the northern Rockies and Plains for the weekend, the baroclinic zone wiggles back east, with widespread 40s and 50s expected across the area again. Upper ridge stands pat over the central CONUS into early next week, with dry and mild conditions continuing across the area. Temperatures remain well above average into the middle of next week. && .AVIATION...(For the 18Z TAFS Through 18Z Wednesday) Issued At 1006 AM MST Tue Dec 30 2025 VFR conditions are expected through the period. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...15 AVIATION...SE