Julie Parrish

Publication Date


Document Type


First Advisor

Changnon, David

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Geography


Drought forecasting--Middle West; Cyclones--Middle West--Climatic factors; Long-range weather forecasts--Middle West; Middle West--Climate


Winter surface cyclone characteristics, including cyclone frequency, central pressure, speed and direction, were examined from 1950-1990 to determine if a relationship existed to Midwestern hydrologic drought. Using twelve Midwestern 5° latitude equal-area circles, monthly and seasonal cyclone data were obtained for the analysis. Streamflow values were used to determine hydrologic droughts for 19 Midwestern basins based on several criteria including number of seasons the drought continued. Fifteen of the 19 basins experienced two or more hydrologic droughts between 1950-1990. Two analyses were performed, each dividing the study period of 1950-1990 into phases in order to determine if winter cyclone characteristics were statistically different for winters prior to the beginning of a drought and other non-drought periods through the use of the Student's t-test. The first analysis examined the relationship of a basin's hydrologic droughts to cyclone characteristics from individual circles, while the second analysis examined the relationship between a basin's hydrologic droughts to the cyclone information based on averaging all 12 Midwestern equal-area circles. Both analyses found statistically significant differences for cyclone frequency and the cyclone characteristics between the different periods. However, the results are limited and one analysis did not prove to be substantially more beneficial than the other.


Includes bibliographical references (pages [55]-57)


vii, 77 pages




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