Temperatures started off Thursday morning quite mild over Iowa, but a frontal boundary created a strong temperature gradient by the afternoon as shown by the featured map analysis valid 3 PM CDT (20 UTC). Far northwestern Iowa is shown near 40°F while far southeastern Iowa is into the 80s. This boundary helped to fire some late afternoon thunderstorms, but the majority of the storms were east of the state. The featured map is from the IEM Reanalysis project which attempts to provide weather variables consistently on a spatial grid.