Abstract
Observations of thunderstorm events by mouth for the period 1948–77 at 106 stations in the central United States are used to examine persistent spatial patterns in thunderstorm occurrence. A principal components analysis reveals that nearly 55% of the variance is explained by the first four components. An oblique rotation was performed using the first four components, with distinct synoptic-scale patterns revealed. The synoptic environments of four months representative of the four rotated components arc briefly described. A regionalization is presented that was developed by assigning each grid point to the rotated component on which it has the highest loading.
