Dust Storm — Imperial County Except the Lower Colorado River Valley, California

2012-08-13 · Imperial County Except the Lower Colorado River Valley, California

Event narrative

Isolated thunderstorms developed to the south of the Mexican border, and they affected the southern portions of Imperial county during the afternoon hours on August 13th. Due to the excessive heat and dry conditions, the high based thunderstorms were able to generate strong gusty outflow winds estimated to be in excess of 50 mph. The winds spread to the north and picked up substantial amounts of dust and sand, creating dust storm conditions which affected towns such as Calexico and Seeley. At about 4 pm, a trained weather spotter 5 miles southwest of Seeley reported visibility at one quarter mile on Interstate 8, a result of the dense blowing dust. Another trained spotter in Calexico reported near zero visibility in a dust storm, at 410 pm. Finally, at 405 pm local emergency managers in Heber reported visibility near zero in a dust storm, and they estimated winds to be at least 50 mph.

Wider weather episode

Isolated thunderstorms developed to the south of the Mexican border during the afternoon hours on August 13th. The combination of excessive heat and dry conditions allowed the high based thunderstorms to produce strong and gusty outflow winds, estimated to be 50 mph or higher. The strong outflow winds spread to the north into the southern portions of Imperial county, and they generated dense blowing dust and sand, creating dust storm conditions in towns such as Calexico, Holtville and Seeley. The winds were strong enough to blow down a number of trees, some of which fell down and blocked roadways.

Source: NOAA Storm Events Database, event_id 397407. Narrative written by the NWS forecast office that issued the report.