This research was supported by the National Science Foundation under Grants ATM-9618684 and ATM-9812384. The authors thank three anonymous reviewers and Michael Montgomery for their comments and suggestions. The nonhydrostatic simulations were carried out using the Advanced Regional Prediction System (ARPS) developed by the Center for Analysis and Prediction of Storms (CAPS), University of Oklahoma. CAPS is supported by the National Science Foundation and the Federal Aviation Administration through combined Grant ATM92-20009.
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