FXUS63 KUNR 201716 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 1116 AM MDT Fri Mar 20 2026 .KEY MESSAGES... -Unseasonably warm with record highs expected Saturday -Cooler to start next week with some light precip possible Saturday night into Sunday -Mild and dry weather then returns mid next week before another cool down toward the end of next week && .DISCUSSION...(This Afternoon Through Thursday) Issued at 1113 AM MDT Fri Mar 20 2026 Mean western CONUS ridge will continue to support unseasonably warm weather through much of mid next week. A ridge topping impulse does cool things down Sunday and Monday, however things dry back out and warm up mid week as the ridge rebuilds. Warm and dry westerly flow is ongoing across the area. Thermal ridge will shift into the region with the warmest day for most areas expected to be Sat. A cool front will sag into the region Sat, with most guidance stalling this feature out INVOF of I90 until evening. Areas to the south of the front will definitely reach the low 90s, with areas along and just to the north potentially losing some mixing potential. Did adjust max temps for that. If things remain on track, record high temps will likely be set at many locations including Rapid City where the all time March highs (85 and 84 at downtown and the airport respectively) could be broken as highs are forecast to reach the upper 80s to low 90s there. Ridge topping impulse will move through Sat night with an associated cold front. A period of breezy NW winds are expected Sat evening behind the front. This system will bring a few showers to the region Sat night into Sunday, esp across NW SD. Upper ridge then rebuilds mid next week with warm and dry weather returning before another cool down occurs toward the end of the week per a strong upper trough in westerly flow, although forecast confidence late next week is low attm. && .AVIATION...(For the 12Z TAFS Through 12Z Saturday Morning) Issued At 459 AM MDT Fri Mar 20 2026 VFR conditions are expected through the forecast period. && .FIRE WEATHER... Issued At 1113 AM MDT Fri Mar 20 2026 Very dry, unseasonably warm, and breezy conditions will continue through Sat. In addition, a cold front will move through Sat evening, supporting gusty north winds for a period. Given poor recovery tonight with even warmer/drier conds Sat, have extended most of the current red flag warning into Sat evening. Left the northern edge of zones out for now as a trough will settle south into the area along/north of I90 and support slackening winds. To the south, breezy winds are expected with with west winds gusting over 25 mph. Did add south central SD to the red flag warning given very dry conds with breezy WSW winds expected by afternoon. Cooler Sunday and Monday, with elevated to critical fire weather conds expected to return by mid next week. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Red Flag Warning until 9 PM MDT this evening for SDZ323-324-327- 329-331. Red Flag Warning until 9 PM MDT Saturday for SDZ319>322-325-326- 332-333. Red Flag Warning from noon to 10 PM CDT Saturday for SDZ334-335. WY...Red Flag Warning until 9 PM MDT Saturday for WYZ314>318. && $$ DISCUSSION/KEY MESSAGES...JC AVIATION...Wong FIRE WEATHER...JC