Winter Weather — Clay, Iowa
2019-12-28 to 2019-12-30 · Clay, Iowa
Event narrative
A brief period of light freezing rain produced a glaze of icing early on Saturday, December 28 before temperatures climbed above freezing. Light mixed precipitation returned and changed quickly to snow during the afternoon of December 29, then continued into December 30 producing hazardous travel. Snowfall totaled 2.6 inches 3 miles west northwest of Everly and 1.9 inches at Spencer. Wind gusts reached as high as 40 mph at Spencer by early Monday, December 30, resulting in blowing and drifting snow. Around 1100CST on December 30, a northbound semi-truck lost control on snow-covered U.S. Highway 71 approximately 2 miles south of Spencer. A fatality (indirect) occurred to the driver of a southbound minivan when the vehicle struck the semi-trailer extending across the highway.
Wider weather episode
A deep trough across the southwestern U.S. in the early morning of Saturday, December 28 pushed eastward through the day, allowing low pressure to organize near the Oklahoma and Texas Panhandles. The storm intensified as it moved into eastern Nebraska and western Iowa by 0600CST December 29. Strong warming aloft ahead of the system led to periods of light rain or light mixed precipitation, while heavy snow organized in the trowal over central and northeast South Dakota.
Impacts from the storm became significant as the storm closed off in the mid-levels and slowed movement, only reaching southern Minnesota by 0600CST December 30. Precipitation changed over to snow as colder air collapsed southward, and winds increased to a gusty 40 to 55 mph across southeast South Dakota and adjacent areas. Snowfall totals ranged from 10 to 18 inches from the James River Valley westward, to 1 to 3 inches across much of northeast Nebraska and northwest Iowa. A record daily precipitation of 1.38 inches was measured in Sioux City on December 28.
Source: NOAA Storm Events Database, event_id 870508. Narrative written by the NWS forecast office that issued the report.