Phoenix got a rough reminder of how fast desert weather can turn last week. According to KTAR News, two late-night dust storms swept across the Phoenix area and both reached Category 5 on a severity scale developed by Arizona State University researchers.
That matters because Category 5 is the top end of the scale. Ryan Heintzman, an assistant teaching professor in ASU’s School of Geographical Sciences and Urban Planning who helped create the Phoenix Dust Storm Scale, told KTAR News 92.3 FM’s Outspoken with Bruce & Gaydos that the scale is based on dust concentration in the air. He said a five means five times as much dust in the air as a one, which helps explain why these storms can feel so overwhelming even when they pass quickly.
KTAR reports that the two haboobs were only the fifth and sixth storms in the past 16 years to reach Category 5. The first storm struck late last Monday, and the second followed early Thursday. Both brought wind speeds of about 50 mph and cut visibility to about a half-mile, leaving a brown haze hanging around the following mornings.
One of the storms also stood out for its length. KTAR says one of last week’s dust storms lasted a record 16 hours, according to Heintzman. That kind of staying power is part of what makes these events so memorable for people across the Valley: it is not just the wall of dust itself, but the way it can linger and keep the air looking and feeling unsettled well after the worst of it has moved on.
Haboobs form when strong downdrafts from thunderstorms stir up loose dust and dirt and push it ahead of an approaching storm cell, KTAR explains. They can create massive walls of dust that sharply reduce visibility, endanger drivers and cause health problems. In this case, KTAR notes that the late-night timing likely helped reduce the impact a bit, since fewer people were out on the roads when the storms hit.
For Phoenix, it was a striking stretch of weather in a single week — and a reminder that in the desert, the sky can change fast.
