Atmospheric River Researchers Tap OCWD Staff
Orange County Water District (the District; OCWD) staff will go to just about any lengths, or in this case heights, to bring abundant water to north and central Orange County. This was evidenced recently as Recharge Planning Manager Adam Hutchinson joined a mission to fly into an atmospheric river (AR) storm event to gather vital data to improve atmospheric river forecasts.
Led by Scripps Institution of Oceanography at UC San Diego, in partnership with the National Oceanic and Atmospheric Administration (NOAA), the National Weather Service, NOAA’s Office of Marine and Aviation Operations, and the U.S. Air Force Reserve 53rd Weather Reconnaissance Squadron “Hurricane Hunters,” the weather scouting flight was one of up to 12 storm missions scheduled between Jan. 23 and March 18.
Atmospheric rivers are storms that bring large amounts of precipitation. They can deliver up to half of California’s total annual precipitation and cause 90% of flooding in the state, according to Scripps Oceanography.
Adam’s 8-hour flight on a NOAA Gulfsteam IV aircraft took him into an atmospheric river event in the Pacific Ocean near Baja California. Thirty dropsondes were released into the path of the storm. Each dropsonde records and transmits data on humidity, temperature, wind speed, wind direction and location to the aircraft as it falls through the atmosphere. The retrieved data will be used in the National Weather Service’s operational weather forecast models, as well as other major global modeling centers.
Locally in Orange County, OCWD has been collaborating with the U.S. Army Corps of Engineers and the Center for Western Weather and Water Extremes at Scripps Institution of Oceanography to study atmospheric rivers. This research supports implementation of Forecast Informed Reservoir Operations (FIRO) at Prado Dam. FIRO is a management strategy to use modern weather forecasting, runoff modeling and watershed monitoring to help water managers selectively retain or release water from reservoirs in a manner that reflects current and forecasted conditions.
The ultimate goal of FIRO at Prado Dam is to update dam water conservation and flood control guidelines to improve water management and environmental outcomes without diminishing flood risk management or dam safety. This will allow OCWD to increase its capture of stormwater to be used to replenish the groundwater basin, which provides 77% of the region’s water needs.