Special thanks go to Dr. T. N. Krishnamurti. This work was inspired by his stimulating discussions. The first author also wishes to thank Drs. W. Han and H.S. Bedi for their helpful suggestions. The data used in this study was provided by Dr. T. N. Krishnamurti's lab.
The support provided by NSF grant ATM-9413050 managed by Dr. Pamela Stephens is gratefully acknowledged.
The computer facilities were provided by the Special SCD Grant 35111089 in NCAR and National Science Foundation 35111100. Additional computer support was provided by Supercomputer Computations Research Institute at Florida State University.