Dust Storm Shrouds Phoenix in Zero Visibility

(METEOROLOGYNEWS.COM)  A spectacular dust storm blanketed Phoenix, Arizona on Tuesday evening, reducing visibility to a quarter-mile or less in some areas.

Such strong dust storms — sometimes referred to as a haboob — is a visually-impressive weather phenomena that is common in arid regions such as the desert Southwest.  Dust storms frequently begin when a gust front or other strong wind loosens sand and dust from the Earth’s surface.  The particles are transported by the strong winds and are scraped along the ground, loosening more particles.

This dust storm was the result of a long-standing drought in the region that has been compounded by recent record heat.  As the heat builds and less precipitation falls, the ground dries out and a feedback cycle exacerbates the conditions over time.  When the summer monsoon winds build over the dry air, they dislodge the lose particles of dust and sand from the ground.

As these particles begin to shift and skip across the ground, they dislodge more particles and the smallest particles begin to remain suspended in the air.  The situation compounds over time, creating blankets of dust sometimes hundreds of feet thick.  This still image captured from the video of a local media reveals the depth of the storm as well as the magnitude, as shown against the backdrop of downtown Phoenix.

Even the interior of Sky Harbor Airport was not immune to the fine dust particles that seemed to infiltrate any open door, window, or gap in buildings in the region.

While weather radar is traditionally used to detect precipitation, it has also been used to detect many other phenomena.  Now we can add dust storms to the list.  Imagery from the evening revealed the sheer volume of dust elevated into the atmosphere, rising thousands of feet — perhaps as high as a mile — into the sky.  As the dust drifted over Phoenix from the south-southwest, the radar station based in Phoenix was able to detect it.

A visible satellite image of the region reveals widespread thunderstorms blossoming throughout the region.  While the thunderstorms provided hope for widespread rain, many of the storms were relatively dry:  the rain that fell from the bases of the storms often failed to reach the ground, providing instead only the strong outflow of air that resulted in the dust storm that blanketed Phoenix.  However, some areas reported brief downpours following the dust storm, resulting in wet layers of mud coating all outdoor surfaces.