Improving Sub-seasonal to Seasonal (S2S) Precipitation Forecasting to Support Water Management Decision-making

The Western States Water Council and the California Department of Water Resources cosponsored workshop in a recurring series continuing a dialogue among western states and the National Oceanic and Atmospheric Administration (NOAA), and the research community on improving sub-seasonal to seasonal (S2S) precipitation forecasting to support water management decision-making.  The agenda included topics addressing progress being made in forecasting atmospheric river storms beyond a two-week weather model time scale, assimilation of new research observations into NOAA’s weather models, scoping a pilot project for improving S2S precipitation forecasting to support Colorado River Basin drought contingency planning, and the new forecast-informed reservoir operations (FIRO) pilot project on the Santa Ana River.

The workshop was held in San Diego, California on May 14-16, 2018 at the Doubletree San Diego Downtown.  It included an optional field trip on May 17 to the Orange County Water District’s groundwater recharge facilities, which constitute part of the Santa Ana River (FIRO) pilot project.

AGENDAS2S Workshop Agenda


May 14, 2018

Workshop Background – Jeanine Jones, California Department of Water Resources (CDWR)
Advancing NOAA’s Subseasonal and Seasonal Prediction in Support of the Weather Act of 2017 (PL115-25, 201) – Dave DeWitt, National Weather Service, Climate Prediction Center
Reaping the Benefits of California’s Investment in Observations & Research – Mike Anderson, CDWR
Incorporating Satellite Data into Weather, Climate and other Predictive Models – Stephanie Granger, National Atmospheric and Space Administration, Jet Propulsion Laboratory (NASA JPL)
Reclamation’s Sub-Seasonal Climate Forecast Rodeo, Participants’ Performance to Date – Dave Raff, Bureau of Reclamation
June 2018 International Atmospheric Rivers Conference – Anna Wilson, Scripps Institution of Oceanography

May 15, 2018

Sub-seasonal to Seasonal Forecasting and Predictive Needs in Texas – Nelun Fernando, Texas Water Development Board (by phone
Improving 1-4 week NOAA Precipitation Forecasts for California – Tom Hamill, NOAA Earth Systems Research Lab & Mike Anderson, CDWR
Oregon Applications for S2S Forecasting and Atmospheric River Information – Keith Mills, Oregon Water Resources Department
Experimental S2S Forecasts for California: Wet/AR and Dry/Ridging Conditions – Duane Waliser, NASA JPL
Scripps Atmospheric River Activities including This Winter’s Observations in the Pacific Northwest – Marty Ralph, Scripps Institution of Oceanography
Seasonal Prediction of Western United States Snowpack – Sarah Kapnick, NOAA Geophysical Fluid Dynamics Lab
Importance of Seasonal Forecasting in the Colorado River Basin – Colby Pellegrino, Southern Nevada Water Authority
S2S Prediction Research at Colorado State University – Cory Baggett, Colorado State University

May 16, 2018

Closed/Cut-Off Low Pressure Systems – What They Are and Forecasting Challenges – Roger Pierce, WestFAST & National Weather Service (NWS)
Mechanisms Contributing to Cool-Season Precipitation in the Upper Colorado River Basin – Pending Work for CDWR – Ben Hatchett, Western Regional Climate Center
Follow-up Potential for Prior Reclamation-Funded Research on Inland-Penetrating Atmospheric Rivers – Kelly Mahoney, NOAA Earth Systems Research Lab
Forecasting Challenges in Upper Colorado River Basin – John Lhotak, Colorado Basin River Forecast Center (by phone)
This Winter’s Southern California Forecasting Challenges – Alex Tardy, NWS San Diego
Status of Research Pilot Projects on Forecast-Informed Reservoir Operations – Jay Jasperse, Sonoma County Water Agency (Lake Mendocino)
Replenishing Groundwater for Sustainability –Adam Hutchinson, Orange County Water District

Story in Earth Magazine
Rivers in the sky: Improving predictions of atmospheric rivers to reduce risk 
by Steve Murray