A BLUEPRINT FOR THE USE OF NOAA/CPC PRECIPITATION CLIMATE FORECASTS IN AGRICULTURAL APPLICATIONS

Authors: Schneider, Jeanne; Garbrecht, Jurgen

Submitted to: American Meterological Society Preprint on Special Symposium on Hydrology
Publication Type: Proceedings
Publication Acceptance Date: 8/2/2001
Publication Date: 12/15/2001
Citation: SCHNEIDER, J.M., GARBRECHT, J.D. A BLUEPRINT FOR THE USE OF NOAA/CPC PRECIPITATION CLIMATE FORECASTS IN AGRICULTURAL APPLICATIONS. PROCEEDINGS OF THE AMERICAN METEROLOGICAL SOCIETY. 2001. p. J71-J77.

Interpretive Summary: Seasonal forecasts of precipitation are issued by NOAA's Climate Prediction Center and provide potentially useful information to support planning and management in agriculture and resource conservation. Climate forecast performance has been improving over time, but despite these improvements they may or may not be currently useful for all applications at all locations within the United States. Due to the technical and broad nature of the forecasts, they need to be evaluated, interpreted, and assessed with respect to their ability to meet the needs of a particular application. While such forecast analysis is best performed with a specific application in mind, our research has identified four generally applicable assessments of forecast characteristics, intended to provide guidance for managers or producers who are first time users of the forecasts. The four categories are: forecast content; degree of difference between forecast conditions and dnoraml conditions; forecast reliability; and a check to determine ehether he forecast needs to be modified before use at a particular location. The assessments address both general and location specific considerations. For example, the forecasts have been shown to vary in usefulness and dependability with region. This paper is a compilation of the four assessments that can be used to obtain an initial evaluation of the forecasts' ability to meet the needs of a particular application.

Technical Abstract: Experimental precipitation climate forecasts are now routinely available from the National Oceanic and Atmospheric Administration. These forecasts specify the probabilities for total precipitation relative to climatological distributions, for 13 overlapping 3-month periods covering the coming year, for each of 102 forecast divisions covering the contiguous sUnited States. The forecasts are a rich source of potentially useful information, but are complex, and must be interpreted for a particular application and location. This blueprint presents a general initial evaluation procedure for managers or producers who are considering using experimental precipitation climate forecasts in agricultural management. Assessments of forecast characteristics are organized into four broad categories, presented in the expected order of importance to a manager or producer. The assessment categories are forecast content, forecast departures from climatology, forecast reliability, and comparison of forecast division climatology to local climatology. A procedure for spatially downscaling division forecasts is outlined for situations where the fourth assessment reveals a need for adjustment to local conditions. Forecast departures from climatology have been more frequent in the Desert Southwest, the Pacific Northwest, and along the Gulf Coast. Forecast reliability(in terms related to their success in predicting the variability of precipitation), measured over all seasons, varied significantly with region. Differences between forecast division and local climatologies can be large enough to require location-specific adjustments before use of the forecasts. The experimental precipitation climate forecasts may or may not be currently useful for all applications at all locations.