The most powerful storm in recorded history for the region swept through the Southwestern United States last week, “bringing deadly flooding, tornadoes, hail, hurricane force winds, and blizzard conditions.” Rain dumped on Los Angeles, San Diego, and Phoenix, as mountains received up to four feet of snow. Wind gusts exceeding 90 miles per hour, tornadoes, and water spouts spun off the monster storm. Over 159,000 people lost power in the storm’s wake. Meteorologist Jeff Masters wrote on Friday that the storm was “truly epic”:
We expect to get powerful winter storms affecting the Southwest U.S. during strong El Niño events, but yesterday’s storm was truly epic in its size and intensity. The storm set all-time low pressure records over roughly 10–15% of the U.S. — over southern Oregon, and most of California, Nevada, Arizona, and Utah.
“California has been pounded by a series of winter storms and rains,” said Gov. Arnold Schwarzenegger during a news conference in Los Angeles. “The storms brought wind gusts of up to 80 miles [an hour] across the mountains and the canyons, major highways and roads were closed, flights have been grounded, thousands of homes and businesses lost power, more than 2,100 homes were evacuated. Sadly and unfortunately, some people lost their lives.”
However, this record storm is only a preview of what is to come in a warmer world. The USGS Multi Hazards Demonstration Project at the California Institute of Technology is developing the ARkStorm scenario to “tackle what would happen if a series of powerful storms lashed at the state for 23 days”:
In the scenario, the storm system forms in the Pacific and slams into the West Coast with hurricane-force winds, hitting Southern California the hardest. After more than a week of ferocious weather, the system stalls for a few days. Another storm brews offshore and this time pummels Northern California. Such a monster storm could unleash as much as 8 feet of rain over three weeks in some areas, said research meteorologist Martin Ralph with the National Oceanic and Atmospheric Administration, who is part of the project. It makes the latest Pacific storm system look like a drop in the bucket.
“Ironically, the team had scheduled meetings at Caltech to learn about the fictional storm’s impact to dams, sewage treatment plants, transportation and the electrical grid,” the Associated Press’s Alicia Chang writes. “About a dozen canceled due to the storms.”