ARkStorm

The USGS Multi Hazards Demonstration Project (MHDP)’s second full scenario, called ARkStorm, addresses massive U.S. West Coast storms analogous to those that devastated California in 1861–62.

The ARkStorm is patterned after the 1861–1862 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.

HAZUS-MH was used extensively for the ARkStorm analysis.

MORE INFO: USGS Multi-Hazard West Coast Winter Storm Project

MORE INFO: Overview of the ARkStorm Scenario

The overview report summarizes a winter storm scenario called ARkStorm (for Atmospheric River 1,000). Experts have designed a large, scientifically realistic meteorological event followed by an examination of the secondary hazards (for example, landslides and flooding), physical damages to the built environment, and social and economic consequences. The hypothetical storm depicted here would strike the U.S. West Coast and be similar to the intense California winter storms of 1861 and 1862 that left the central valley of California impassible. The storm is estimated to produce precipitation that in many places exceeds levels only experienced on average once every 500 to 1,000 years.

Report: Overview of the ARkStorm Scenario (.pdf)...