Crop-Hail Intensities in Central and Northwest United States

Abstract

Information on hail intensity is not readily available on a national or local scale. As a result, a study was made to obtain general estimates of the mean areal patterns of hail intensity in the central and northwestern continental United States. Although the results of the study are based on indirect measures of hail intensity developed from crop-insurance data, the results provide useful estimates of a phenomenon heretofore unmeasured. Intensity measures derived from crop-insurance data available for 19 states revealed that summer hailfalls at points in the lee of the Rocky Mountains were 5 to 15 times more intense than those in the Middle West. A good correlation was found for the mean intensity indices of states and the mean hailday frequencies, suggesting that the widely available climatological data on hail frequency could provide useful estimates of hail intensity in other states.