SEASONAL CLIMATE FORECASTS: SUMMARY OF CURRENT OPPORTUNITIES ACROSS THE CONTIGUOUS UNITED STATES

Authors: Schneider, Jeanne; Garbrecht, Jurgen; Steiner, Jean

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/2005
Publication Date: 11/6/2005
Citation: Schneider, J.M., Garbrecht, J.D., Steiner, J.L. 2005. Seasonal climate forecasts: summary of current opportunities across the contiguous United States [abstract]. ASA-CSSA-SSSA International Annual Meeting, November 6-10, 2005, Salt Lake City, Utah. 2005 CDROM.

Interpretive Summary: Seasonal climate forecasts are issued monthly for subsequent overlapping 3-month periods, out to a full year ahead, by NOAA's Climate Prediction Center (CPC). These probabilistic forecasts represent shifts in odds relative to a 30-year climatology. Opportunities to augment agricultural decision support systems with seasonal climate forecasts are expected to be more numerous in regions with frequent forecasts for climate departures that depart significantly from climatology. A measure of forecast utility was developed to identify such regions; to examine any variation of utility with forecast direction (warmer vs. cooler, or wetter vs. drier, than average); and to assess forecast reliability. The results indicate that forecasts for warmer than average conditions are frequent and reliable for much of the U.S., especially in the Desert Southwest, Pacific Northwest, and Gulf Coast and Southeast regions. Cooler than average forecasts are rare and generally not reliable. Wetter than average forecasts occur more frequently and are reliable in the Desert Southwest, the coastal Pacific Northwest, and along the Gulf Coast through Florida. Drier than average forecasts are frequent and reliable in southern California, Arizona, southwest New Mexico, southwest and southern Texas, Florida, and the coastal Carolinas.

Technical Abstract: Seasonal climate forecasts have been issued operationally since December 1994 by NOAA's Climate Prediction Center (CPC) for the contiguous United States. These probabilistic forecasts predict total precipitation and average air temperature, covering overlapping 3-month periods out to a full year ahead. Reliable forecasts present opportunities for better planning and management in response to seasonal climate variations. Unfortunately, forecast skill scores offered by CPC combine the performance of all forecasts issued at a particular time across the contiguous United States. This makes it impossible to determine the reliabiity of the forecasts for a particular region, or to determine if the reliability differs with direction (wet versus dry, or warm versus cool). A measure of forecast utility has been developed and applied to individual forecast divisions (each approximately 90000 sq. km.), making it possible to examine the utility of forecasts by region and forecast direction. This utility measure identifies the "where and which direction" of current opportunities for agricultural decision support offered by CPC's seasonal climate forecasts.