United States streamflow probabilities and uncertainties based on anticipated El Niño, water year 2003

Experimental Long-Lead Forecast Bulletin
By: , and 


  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS | Dublin Core


During the course of spring and summer 2002, tropical sea-surface temperatures in the eastern Pacific Ocean have warmed and the wind and pressure fields have shifted, so that by August, there was considerable confidence that water year (October–September) 2003 will be characterized by a weak to mild El Niño climate ( At the same time, the Pacific Decadal Oscillation pattern of sea-surface temperatures in the North Pacific (Mantua et al., 1997) has shifted towards a more neutral state than in the past several years and will not be considered in detail here. Previous studies of the connections between El Niños and streamflow in the United States by the authors (e.g., Redmond and Koch, 1991; Cayan and Webb, 1992; Cayan et al., 1999; Dettinger et al., 2001) indicate that El Niño conditions influence historical streamflow distributions to varying extents. These conclusions, along with those of other researchers, suggest that foreknowledge of El Niño conditions can inform seasonal outlooks for streamflows throughout the Americas and elsewhere. For example, Dettinger et al. (2001), as distilled here into Fig. 1, showed that historical annual streamflow totals have correlated negatively with the Southern Oscillation Index (SOI, which is negatively associated with El Niños) in the U.S. Southwest as well as in the subtropics of South America, and correlate positively in the U.S. Northwest, in much of tropical South America, and, perhaps, in southernmost South America. These interhemispheric bands of El Niño influence are a matter of considerable concern for water- and land-managers throughout the Americas, and expand upon results from previous studies in the western United States (e.g., Redmond and Koch, 1991; Cayan and Webb, 1992), including a recent analysis by Pizarro and Lall (2002), where water availability and hydrologic extremes are particularly pressing issues.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title United States streamflow probabilities and uncertainties based on anticipated El Niño, water year 2003
Series title Experimental Long-Lead Forecast Bulletin
Volume 11
Issue 3
Year Published 2002
Language English
Contributing office(s) San Francisco Bay-Delta, Pacific Regional Director's Office
Description 7 p.
First page 46
Last page 52
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page