ASSESSING IMPACTS OF A CLIMATOLOGICALLY UNIQUE YEAR (1990) IN THE MIDWEST

Operations of a regional climate center in the Midwest during 1990 involved preparation of month-ending assessments of the regional weather conditions and their environmental and socioeconomic impacts. These assessments were analyzed to define the kinds of impact information that can be quickly gathered and why it is seen as useful. Major users were federal, state, and local government agencies that applied the information in measuring event severity and in making decisions about responses. Since 1990 was an anomalous weather year in the Midwest, being the warmest and wettest year on record, the impacts were noteworthy and relevant to the climate change issue. The excessive storminess of 1990 produced near record losses to property and in human lives. The excessive January-June wet conditions led to extensive flooding and delayed the growing season. Interestingly, May and October, which had below normal temperatures, did not experience late or early frosts that would have been devastating to the delayed growth stages of Midwestern crops. Many major weather impacts in the Midwest are caused by such events and the assessment of effects of a changed future climate will require that global climate models describe shifts in average dates of first and last freezes, the frequency of heavy rain events, and intensity of severe storms.