FXUS63 KUNR 070358 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 958 PM MDT Wed May 6 2026 .KEY MESSAGES... - Warming trend as we move towards the weekend. - Active northwest flow will bring chances for showers/storms, mainly Thursday and Saturday. && .UPDATE... Issued at 942 PM MDT Wed May 6 2026 Minor changes to the previous forecast. Storm track has shifted south some in forecast models for both Thur and Sat impulses. This has resulted in a SW shift in the higher pops, most noticeable in western SD. Dropped highs a couple degrees Thur and esp Fri as the cool front moves through faster. Still on track for a sig warm up next week with 80s and few 90s possible early next week. All else on track. && .DISCUSSION...(This Evening Through Wednesday) Issued at 1213 PM MDT Wed May 6 2026 Current Water Vapor and upper air models show northwest flow over the FA, as weak troughing sits over the Great Lakes region and upper ridge builds over the far western CONUS. 18Z Surface analysis has high pressure centered over eastern Wyoming this afternoon. Satellite shows some low-top CU development over the forecast area. Temperatures currently sit in the 40s and low 50s over the region, with winds out of the northwest. Upper ridge builds over the Rockies tonight and Thursday, resulting in warmer temperatures for the area. Highs Thursday will be in the upper 50s and 60s, while Friday will see widespread 70s. Main concern for Thursday will be the potential for showers/storms as a shortwave rides the northwest flow through the CWA. The better forcing region for precipitation potential looks to be from northeastern WY into the Black Hills and southwestern SD. Low CAPE values (200-400 j/Kg) and some low eff shear will be enough to spark some thunderstorms in the showery regions. Given the forecast thermal profiles, not expecting any severe storm potential, but some gusty winds 40-50mph may be possible near showers/storms. Dry conditions return Friday, but precipitation chances return Saturday as a weak wave moves thorugh WY into SD/NE. Upper ridge slides over the Rockies into the northern and central plains early next week, resulting in continued warmer temperatures and mostly dry conditions Sunday through middle of next week. && .AVIATION...(For the 06Z TAFS Through 06Z Thursday Night) Issued At 955 PM MDT Wed May 6 2026 VFR conditions will prevail overnight and into Thursday morning. Scattered rain showers and isolated thunderstorms are expected to develop across northeast Wyoming around 17Z, reaching southwestern South Dakota by 19Z. MVFR/IFR vis/cigs and gusty, erratic winds may be present near thunderstorms. Showers will persist through the remainder of the TAF period. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ UPDATE...JC DISCUSSION/KEY MESSAGES...Dye AVIATION...Schultz