Phoenix Dust Storm
16.4.2012 12:34 | Tornado
"A massive dust storm descended on the Phoenix area,
drastically reducing visibility and delaying flights as strong winds downed trees and left thousands of residents without power.
The dust cloud that moved across the Phoenix valley Tuesday night had formed in an afternoon storm in the Tucson area, and then rolled north across the desert before sweeping over the city like an enormous wave, said National Weather Service meteorologist Paul Iniguez.
Radar data showed the storm's towering dust wall had reached as high as 8,000 to 10,000 feet, or nearly 2 miles, he said.
"This was pretty significant," Iniguez told The Associated Press. "We heard from a lot of people who lived here for a number of storms and this was the worst they'd seen."
By the time the dust cloud neared the metropolitan area, it had started to dissolve but it still towered over the city with a wall of at least 5,000 feet, according to the weather service.
KSAZ-TV in Phoenix reported the storm appeared to be roughly wide in some spots. It briefly covered the city's downtown at around nightfall. The storm was part of the Arizona monsoon season, which typically starts in mid June and lasts through September.
The National Weather Service says strong winds with gusts of up to more than 60 mph in some places rapidly moved the dust cloud northwest through Phoenix and the surrounding cities of Avondale, Tempe and Scottsdale. More than a dozen communities in the area also were placed under a severe thunderstorm watch until 11 p.m. Some 8,000 Salt River Project utility customers were left without power, KNXV-TV reported late Tuesday.
The Federal Aviation Administration said on its website that because of low visibility in the area, no Phoenix-bound flights were allowed to leave Las Vegas or Los Angeles airports until 9 p.m., and flights at the airport were delayed for about an hour."
"The word "haboob" comes from the Arabic word habb, meaning "wind." A haboob is a wall of dust as a result of a microburst or downburst. The air forced downward is pushed forward by the front of a thunderstorm cell, dragging dust and debris with it, as it travels across the terrain.
Haboobs occur mostly during the summer months in Phoenix, but are not restricted to the monsoon period. These dust storms are much more serious than dust devils. The wind during a haboob is usually up to about 30 mph (TRY 80+MPH!! 07-07-2011) and dust can rise high into the air as it blows over the Valley. A haboob can last for up to three hours.
Phoenix experiences various degrees of dust storms, but the haboob is the largest and most dangerous. According to the National Weather Service, Phoenix experiences on average about 3 haboobs per year during the months of June through September."