A Twenty-First-Century California Observing Network for Monitoring Extreme Weather Events

Abstract

During Northern Hemisphere winters, the West Coast of North America is battered by extratropical storms. The impact of these storms is of paramount concern to California, where aging water supply and flood protection infrastructures are challenged by increased standards for urban flood protection, an unusually variable weather regime, and projections of climate change. Additionally, there are inherent conflicts between releasing water to provide flood protection and storing water to meet requirements for the water supply, water quality, hydropower generation, water temperature and flow for at-risk species, and recreation. To improve reservoir management and meet the increasing demands on water, improved forecasts of precipitation, especially during extreme events, are required. Here, the authors describe how California is addressing their most important and costliest environmental issue-water management-in part, by installing a state-of-the-art observing system to better track the area's most severe wintertime storms.

Winter Snow Level Rise in the Northern Sierra Nevada from 2008 to 2017

“…Such changes will have negative implications for water availability. The hypothesis also emphasizes the importance of maintaining and expanding hydroclimatic monitoring in mountain environments [5,20,71].…”

“…The relatively low elevation of these basins makes them susceptible to changes in precipitation phase due to warming [18], which has significant implications for winter flooding [9,19] and warm season water availability [15]. Because of the importance of the northern Sierra Nevada for water resources and flood prevention in California and Nevada, a novel network of hydrometeorological measurements exist upstream of the Sierra Nevada [20] and offer a unique means to explore hydroclimatic change in this region. Snow level, or the elevation where snow melts to rain, is a primary control on the sensitivity of mountain snowpack accumulation to climate warming during precipitation events [21].…”

Contrasting Local and Long-Range Transported Warm Ice-Nucleating Particles During an Atmospheric River in Coastal California, USA

“…The coastal atmospheric river observatory (ARO) was developed by the National Oceanic and Atmospheric Administration (White et al, 2013). During the event described herein, both sites had a tipping bucket 10 raingauge, near-surface (10 m) anemometer, GPS receiver capable of estimating integrated water vapor by means of radio occultation, and a vertically oriented radar for vertical sensing of atmospheric properties.…”

Insights into mountain precipitation and snowpack from a basin‐scale wireless‐sensor network

“…It can enable use of new classes of spatially explicit hydrologicmodeling tools to produce quantitative assessments, influence hydrologic forecasting, probe system response to climate and land-cover perturbations, increase process understanding of basin-scale water cycles, and provide defensible scenarios for infrastructure planning over a scale currently not possible. These WSN clusters complement deployments by others to monitor extreme weather events for flood forecasting [White et al, 2013].…”