Surviving the Storm

California’s climate is famously volatile. While the state has averaged about 21 inches of precipitation per year since 1896, any given year can swing wildly from the mean, resulting in incidences of both devastating floods and remorseless drought.

Climate change is increasing the frequency and severity of such extreme weather events: 2014 was the record hottest year in state history, and according to tree-ring data, one of the driest in 500 years. At the same time, three of the wettest years in recorded California history have occurred since 1980. Along with sea level rise, extreme weather events are creating new risks to the world’s great coastal and delta regions, including the San Francisco- Silicon Valley-Oakland Bay Area. Against this backdrop, and with Hurricanes Sandy and Katrinastill in recent memory, what danger do extreme storms pose to the Bay Area economy today?

While the Bay Area is not exposed to hurricanes, it is vulnerable to prolonged periods of heavy rainfall, elevated tides and gale force winds known as “atmospheric rivers”. These “rivers,” so nicknamed for the long, ribbon-like bands of moisture that stretch across the Pacific Ocean, can be enormous. This report outlines the potential economic consequences of a hypothetical atmospheric river that contains the moisture equivalent of 10 Mississippi Rivers. In this storm event, daily life slows to a crawl as the region is pummeled by 12 inches of rain over seven days, causing widespread flooding and disruption to road and air travel.

Read the Full PDF Report on Surviving the Storm »