A long lasting snowstorm blanketed portions of northeastern Wyoming and western South Dakota. Below is a preliminary snowfall total map. The snow fell over a 48 hour period and considerable blowing and drifting snow was noted on Monday the 26th.
A strong upper level low pressure system gained strength across the central Rockies on Friday, November 23, and took aim for the northern plains. The storm exhibited many of the characteristics needed to produce significant snowfall across the region, including a very strong jet stream aloft, cold air, and ample atmospheric moisture. This prompted the National Weather Service to issue Winter Storm Watches, allowing time for residents of the Black Hills region to prepare for the sudden onset of winter weather.
Snow began to fall across the area during the early morning hours of Sunday, November 25. As the low pressure center at the surface tracked along the Kansas/Nebraska border, gusty northerly winds ushered cold Canadian air across the Black Hills region, the coldest air thus far this season. As snow increased in intensity Sunday night and Monday, considerable blowing and drifting snow significantly affected travel across the region. On Tuesday, the snow finally diminished across the area as the storm system moved into the upper Midwest; however, it's effect was still upon us. 16 inches of snow blanketed portions of the northern Black Hills, while most locations across the region received between 4 and 12 inches. With fresh snow on the ground and clearing skies Tuesday night, temperatures plunged to near and below the zero mark for the first time this winter season.