Using climate regionalization to understand Climate Forecast System Version 2 (CFSv2) precipitation performance for the Conterminous United States (CONUS)

Abstract Dynamically based seasonal forecasts are prone to systematic spatial biases due to imperfections in the underlying global climate model (GCM). This can result in low‐forecast skill when the GCM misplaces teleconnections or fails to resolve geographic barriers, even if the prediction of larg...

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Bibliographic Details
Main Authors: Satish K. Regonda, Benjamin F. Zaitchik, Hamada S. Badr, Matthew Rodell
Format: Article
Language:English
Published: Wiley 2016-06-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1002/2016GL069150
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Summary:Abstract Dynamically based seasonal forecasts are prone to systematic spatial biases due to imperfections in the underlying global climate model (GCM). This can result in low‐forecast skill when the GCM misplaces teleconnections or fails to resolve geographic barriers, even if the prediction of large‐scale dynamics is accurate. To characterize and address this issue, this study applies objective climate regionalization to identify discrepancies between the Climate Forecast System Version 2 (CFSv2) and precipitation observations across the Contiguous United States (CONUS). Regionalization shows that CFSv2 1 month forecasts capture the general spatial character of warm season precipitation variability but that forecast regions systematically differ from observation in some transition zones. CFSv2 predictive skill for these misclassified areas is systematically reduced relative to correctly regionalized areas and CONUS as a whole. In these incorrectly regionalized areas, higher skill can be obtained by using a regional‐scale forecast in place of the local grid cell prediction.
ISSN:0094-8276
1944-8007