Every tornado, hail and damaging wind report logged for Dakotas since 1950, as recorded by the NOAA Storm Prediction Center. Hail and wind reports only begin in the mid-1950s and climb steeply with population, spotter networks and radar — so the modern end of these charts counts reports, not storms, and a rising line is not by itself a rising risk. Tornado counts carry the same caveat more gently.
This page is where the MRMS radar mosaic will sit — national reflectivity, rotation tracks and hail swaths over the same counties the reports above are counted in. The feed is still being built out across the network.
MRMS · in progressReports come from the NOAA Storm Prediction Center severe weather database, 1950 through —. Significant means a tornado rated EF2 or stronger, hail 2 inches or larger, or wind gusts of 65 knots or more. Ranks are among the 50 states and the District of Columbia. Counts are attributed to the state a report was logged in, which is the finest resolution this database publishes — county-level and metro-level breakdowns are not part of it, so the figures here describe whole states.