giant dust storm in arizona

Phoenix residents love to talk about our weather. The extreme heat, scary-looking dust storms, and sudden downpours and floods make for great conversation starters and anecdotes. At least they do until someone uses the words “haboob” for a dust storm or “monsoon” for a rainstorm.

When someone utters these words, someone else inevitably jumps in to offer a correction. They will claim that those terms only apply to certain regions of the world and not Arizona.

Here’s where the confusion comes from.

The major dictionaries do describe haboobs and monsoons as being in Africa (the phrase “haboob” originated in Sudan) and India, respectively. However, those are the regions that most famously experience the events. The mechanisms behind the phenomena are universal.

Haboob

Per the National Weather Service, a haboob occurs when a thunderstorm suddenly collapses or creates a “downburst,” which violently blasts air downward and outward, pushing sand, dust and other debris in front of it in a vast, high wall.

That’s why a haboob can appear suddenly on an otherwise pleasant day. And, that’s exactly what happens sometimes in Arizona. It certainly was the origin of “the big one” back on July 5, 2011. Most Phoenix dust storm photos and videos you will see were shot on that day, incidentally.

By contrast, a more typical dust storm requires a windy day and results from strong winds stirring up dust and debris. So, in Arizona all haboobs are dust storms, but not all dust storms are haboobs.

Of course, some meteorologists we found online also classify dust storms based on visibility. In that system, our Southwest variety don’t get dense enough to qualify as a true “haboob.” So, the debate will probably continue.

Whatever you call it, learn how to avoid the dangers of blowing dust.

Monsoon

The term “monsoon” just means a seasonal shift in wind direction. For India, the wind shifts from north to southeast. Instead of dry land air, the wind brings wet ocean air.

In Phoenix, and the rest of the Southwest, our shift happens in June/July. Instead of blowing west over the dry desert, the wind blows from the east or southeast carrying water vapor from the Gulf of Mexico. In fact, the National Weather Service calls this shift the North American Monsoon System and created a website about it called Monsoon Safety.

That being said, not every storm that happens during our monsoon season — June 15 to September 30 — meets the technical definition of a “monsoon.” However, if you try to be that accurate when you talk about the weather, you’re going to run out of people who will talk to you.

Whether a monsoon or not, learn the dangers you need to avoid during heavy rain.

Bonus: Hot

Phoenix gets hot; no one will dispute that. However, if you use the word “hot” to describe the mild and pleasant temperatures below 100 degrees, someone will correct you. And they’ll be right.

– Justin Ferris, Phoenix.org

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