The National Weather Service has raised the potential for spring flooding across western and south central South Dakota. Minor to moderate flooding from melting snow in the northern Black Hills, northern foothills, and northwestern South Dakota is possible according to the revised Hydrologic Outlook. South central South Dakota may see minor to moderate flooding due to ice jams along rivers. The rest of western South Dakota and northeastern Wyoming has little potential for snowmelt flooding. Moderate flooding is defined as inundation of secondary roads, while minor flooding generally causes little or no property damage but possibly some inconvenience to landowners along the streams.
Heavy snow during the last week of February left over a foot of snow across northwestern South Dakota. Warmer temperatures at the beginning of March started to melt some of the snow, but a cooler weather pattern this weekend will cause some of the water to refreeze.
Above normal snowfall, heavy rain, or rapid snow melt would increase the flood potential, while below normal precipitation and gradually warming temperatures would decrease the magnitude of the current assessment. The Climate Prediction Center outlook through May indicates equal chances of normal, above normal, or below temperatures and precipitation for the Black Hills region.
Additional details can be found in the Hydrologic Outlook bulletin and the Advanced Hydrologic Prediction System web page.