A second cloud of yellow in less than a week overwhelmed suburban Phoenix on Sunday, mixing with torrential rains and gusty winds that wreaked havoc on midday traffic in the area. The thick wall of dust, known as a haboob, which is Arabic for 'strong wind,' was seen making its way through the town of Laveen about eight miles southwest of downtown Phoenix. The greater Phoenix area and northwest and north central Pinal County were under a dust storm warning that expired at 7pm on Sunday.
This comes just days after an enormous dust cloud measuring around 2,000 feet tall and almost 100km wide swept over the city, traveling at 35mph. The dust cut power to some 9,000 homes and caused disruptions at the local airport.
Caused by Arizona's monsoon season which begins in early June and runs through till the end of September, haboob's only occur in Africa, the Middle East, Australia and Phoenix, Arizona.
Known as the granddaddy of dust storms, the haboob is a rare event and is caused by loose dust being blown upwards in the absence of rain and collecting skywards where it is then propelled by another more distant thunderstorm brewing behind it.
Despite some of the 1.5 million residents of Phoenix objecting to the term haboob being used, meteorologists in the city confirmed that they have been using the Arabic word to describe the massive dust storms for over 30 years.
'I think what's going on is that we've had a higher frequency of stronger dust storms over the last couple of years and the term has been in play much more because of that,' said Ken Waters of the Phoenix National Weather Service office to KPHO
Blowing gusts of up to 50 mph at Phoenix Sky Harbor Airport, the haboob is destructive because of the fine dust particles that manage to permeate everywhere during the storm.
'The dust gets into everything ... It gets into electronics, it gets into every nook and cranny,' said Penn State University meterologist Fred Gadomski to NPR.
Familiar to millions of movie-goers from films such as The Mummy
, the Haboob was witnessed by Phoenix New Times
freelance photographer Andrew Pielage, who watched the storm unfold from a mountain viewpoint.
'It is one thing to see it from the ground, but when you are on top of a mountain and you still have to look up to see the top of it you really start to grasp the size and magnitude of the haboob,' said Pielage to the Examiner.com.
An Arizona researcher who studies haboobs said there could be hidden health impacts for millions of people living in the state's dust zone.
According to William Sprigg, of the University of Arizona's Institute of Atmospheric Physics, dust storms carry a noxious mix of fungi, heavy metals from pollutants, chemicals and bacteria that could lead to cardiovascular and eye disease, and other illnesses.
'We already know the cost of these storms in general,' he told the Arizona Republic
. 'I would like to see a much more thorough examination of the effects of the dust on the region.'