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A modeled scenario of U.S. West Coast winter storm events induced by the formation of Atmospheric Rivers (AR) and capable of causing massive and devastating flooding.
ARkStorm was the second full scenario after ShakeOut developed by the SAFRR team. ARkStorm addresses massive U.S. West Coast storms analogous to those that devastated California in 1861-62 and with magnitudes projected to become more frequent and intense as a result of climate change.
Experts were assembled from the National Oceanic and Atmospheric Administration (NOAA), USGS, Scripps Institute of Oceanography, the State of California, California Geological Survey, the University of Colorado, Federal Emergency Management Agency (FEMA), the National Center for Atmospheric Research (NCAR), California Department of Water Resources, California Emergency Management Agency (CalEMA) and other organizations to design the large, but scientifically plausible, hypothetical storm scenario that would provide emergency responders, resource managers, and the public a realistic assessment of what is historically possible.
The ARkStorm storm is patterned after the 1861-62 historical events but uses modern modeling methods and data from large storms in 1969 and 1986. The ARkStorm draws heat and moisture from the tropical Pacific, forming a series of Atmospheric Rivers (ARs) that approach the ferocity of hurricanes and then slam into the U.S. West Coast over several weeks. Atmospheric Rivers are relatively narrow regions in the atmosphere that are responsible for most of the horizontal transport of water vapor outside of the tropics.
Using sophisticated weather models and expert analysis, precipitation, snow lines, wind, and pressure data, the modelers characterize the resulting floods, landslides, and coastal erosion and inundation that translate into infrastructural, environmental, agricultural, social, and economic impacts. Consideration was given to catastrophic disruptions to water supplies resulting from impacts on groundwater pumping, seawater intrusion, water supply degradation, and land subsidence.
In contrast to the recent U.S. East and Gulf Coast hurricanes, only recently have scientific and technological advances documented the ferocity and strength of possible future West Coast storms. ARkStorm is intended to elevate the visibility of the very real threats to human life, property, and ecosystems posed by extreme storms on the U.S. West Coast. This enhanced visibility will help increase the preparedness of the emergency management community and the public to such storms.
The key findings from the full ARkStorm Scenario report are summarized below:
See This is ARkStorm video.
Below are publications associated with this project.