Model surrogates of low-level rotation (such as updraft helicity) indicated 1-km forecasts yielded more accurate next-day tornado forecasts than 3-km forecasts. Furthermore, 1-km model climatologies of precipitation generally aligned better with those observed than 3-km climatologies. Regarding precipitation placement, during the cool season and spring, when large-scale forcing was strong and precipitation entities were large, 1-km precipitation forecasts were more skillful than 3-km forecasts. Conversely, during summertime, when synoptic-scale forcing was weak and precipitation entities were small, 3- and 1-km precipitation forecasts had similar skill.
These collective results differ substantially from previous work finding 4-km forecasts had comparable springtime skill as 1- or 2-km forecasts over the central–eastern CONUS, and hypotheses regarding this disparity will be provided.