most powerful low pressure in 140 years...

Wow---from the Weather Underground site:

The most powerful low pressure system in 140 years of record keeping swept through the Southwest U.S. yesterday, bringing deadly flooding, tornadoes, hail, hurricane force winds, and blizzard conditions. 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. Old records were broken by a wide margin in many locations, most notably in Los Angeles, where the old record of 29.25" set January 17, 1988, was shattered by .18" (6 mb). Bakersfield broke its record by .30" (10 mb). The record-setting low spawned an extremely intense cold front that rumbled thought the Southwest, and winds ahead of the cold front reached sustained speeds of hurricane force--74 mph--last night at one Arizona mountain location, Apache Junction, between Tucson and Phoenix. Wind gusts as high as 94 mph were recorded in Ajo, Arizona, and a Personal Weather Station in Summerhaven (on top of Mt. Lemmon next to Tucson) recorded sustained winds of 67 mph, gusting to 86 mph, before the power failed. Prescott recorded sustained winds at 52 mph, gusting to 67 as the cold front passed, and high winds plunged visibility to zero in blowing dust on I-10 connecting Phoenix and Tucson. The storm spawned one possible tornado in Arizona, which touched down at 8:32 pm MST in Phoenix near Desert Ridge Mall. No damage or injuries were reported. If verified, it would be only the 7th January tornado in Arizona since record keeping began in 1950.