Phoenix Dust Storm a "100-Year Event"
The biggest dust storm in living memory rolls into Phoenix on July 5, 2011, reducing visibility to zero.
Flash in a Haboob
A flash of lightning accentuates a thick blanket of dust over Gilbert, Arizona, on Thursday—the third major dust storm to hit the Phoenix metropolitan area (map) since early July.
The
billowing cloud of dust was about a half mile (0.8 kilometer) high and
50 to 55 miles (80 to 88 kilometers) wide. The storm rolled across
Arizona's Pinal County last night with winds reaching 30 to 40 miles (48
to 64 kilometers) an hour, the
Arizona Republic reported.
Dust
storms are relatively common between June and September in parts of the
U.S. Southwest. Severe dust storms are also called haboobs—Arabic for
"violent wind"—since they often appear in northern Africa and the Middle
East.
Hovering Dust
Huge dust storm, or haboob, yellows the skies over Queen Creek, Arizona.
The
giant walls of dust form in conjunction with thunderstorms. Warm air
flowing over the storm clouds becomes cooler and heavier as it interacts
with moisture. The heavier air is forced downward and then gets pushed
by the front of the thunderstorm cell, dragging dust and debris along
with it.
In the recent Arizona storm, the fine dust particles were blown off agricultural fields as storms moved across the region.
Dusty Roads
Traffic rolls through an intersection in Phoenix, Arizona, as a dust storm looms on August 18.
According to the
Arizona Republic,
the Pinal County sheriff's office received several reports of power
poles falling on moving vehicles—including a school bus—during the
storm, although no major injuries were reported.
Deep in Dust
A pedestrian dashes across Central Avenue in Phoenix, Arizona, during the August 18 dust storm.
Although
the storm dissipated Thursday night, it left hundreds of residents
without power and coated the region in a fine layer of dust that now
needs to be swept away.
Dust from such storms "will end up in your
pool, on your car, it will coat your windows. It's a sediment deposit
that covers everything," Valerie Meyers, of the National Weather Service in Phoenix, told the
Los Angeles Times