Ice Storm — Western Mogollon Rim, Arizona

2010-12-17 to 2010-12-23 · Western Mogollon Rim, Arizona

Event narrative

Several days of low clouds, freezing temperatures, and steady winds produced large accumulations of rime ice on trees and radio towers above 8500 feet in the mountains around Flagstaff. Several hundred trees toppled at elevations of 9000 feet in the Kachina Peaks outside of Flagstaff. Radio equipment atop Mt Elden near Flagstaff also sustained damage. Several radio stations were knocked off the air including the NWR. There were 49 traffic accidents due to snowy and ice roads. There were 13 minor injuries. Eight inches of snow fell in Bellmont and 12 miles north of Parks and 6 inches fell at the Flagstaff Airport.

Wider weather episode

A southwest flow with a relatively shallow moist layer moved over northern Arizona for several days before a cold front swept across the state. The moist layer was below freezing however, the layer was not thick enough or cold enough to allow microphysical dendritical growth to occur. This caused periods of mist at the lower elevations and heavy accumulations of rime ice on trees and radio equipment above about 8500 feet. A cold front ushered in a much thicker layer of moisture, lift, and stronger winds. This brought accumulating snow. Hundreds of trees were brought down by the weight of the ice, snow, and winds.

Source: NOAA Storm Events Database, event_id 273174. Narrative written by the NWS forecast office that issued the report.