CW3E Publication Notice

Better Subseasonal-to-Seasonal Forecasts for Water Management

June 25, 2021

CW3E researcher Dr. Mike DeFlorio, along with co-authors Dr. F. Martin Ralph (CW3E Director), Dr. Duane E. Waliser (NASA JPL/CalTech; Chief Scientist of the Earth Science and Technology Directorate), Jeanine Jones (California Department of Water Resources; Interstate Resources Manager) and Dr. Michael L. Anderson (California Department of Water Resources; State Climatologist) recently published an article in EOS titled “Better Subseasonal-to-Seasonal Forecasts for Water Management”. This effort is supported by the California Department of Water Resources Atmospheric River Program Phase II.

The purpose of this EOS article is to provide an overview of emerging methods in Subseasonal-to-Seasonal (S2S) prediction (2-week to 6-month lead time) that have the potential to support better water management in the western U.S. region. In addition, specific decisions and actions relevant to water resource management that could be affected by improved S2S prediction are identified as a function of lead time. Background context is also given in this article regarding: a) California’s uniquely high interannual variability of total precipitation, which presents a fundamental challenge for water management; b) historical attempts at skillful prediction of western U.S. precipitation, and how emerging methods have the potential to improve upon these previous efforts; and c) the collaboration between researchers at CW3E/JPL (and collaborating institutions) and stakeholders at DWR in designing S2S research methodologies and S2S experimental forecast products that can have more potential benefit to end users in the western U.S. region.

Figures 1 and 2 from the article are included below. They describe, respectively, the lead-time dependent decisions and physical processes related to S2S predictability of precipitation over the western U.S. region, and the quantities of interest and methods investigated at S2S lead times by the CW3E/JPL S2S team.

Figure 1: Overview of lead-time dependent water management decision support, along with physical processes that affect predictability of precipitation over the western United States.

Figure 2: Quantities of interest, methods, and lead times investigated by CW3E/JPL S2S team to benefit water management in the western United States.


DeFlorio, M. J., F. M. Ralph, D. E. Waliser, J. Jones, and M. L. Anderson (2021), Better subseasonal-to-seasonal forecasts for water management, EOS, 102,