Interesting item to note when analyzing PHS forecast CAPE over western South Dakota. This may be terrain induced, but the sharp gradient of CAPE values noted up and and down the western border of South Dakota.  This correlated fairly well with a strong storm or two in the western UNR CWA.

PHS CAPE sharpening gradient in the top left panel.

Wide view of storms in the area using PSv3.

Close in view of several storms on or near that boundary.

David Spritz