Microbursts: Here's what to know about the destructive weather phenomenon that damaged Tempe

PHOENIX - Various parts of the Valley are cleaning up once again, after a severe storm moved across the Phoenix area on Oct. 13.

The storm managed to cause some damage, with officials with the National Weather Service's Phoenix office saying that a microburst moved through parts of the East Valley.

Here's what to know about microbursts, and why they can cause such damage.

What happened?

Local perspective:

On Oct. 13, a powerful microburst hit parts of Tempe, and left over 22,000 residents without power, and over 130 residents are deemed displaced as a result of their apartment unit being damaged by the severe conditions.

"About 1:30 a sudden flash storm came through. It maybe lasted about 10 minutes, and it was a ridiculous amount of rain and the only reason I was aware of it [was] I heard the wind inside the house and saw one of our trees fall onto our house, and then we looked outside and, oh my goodness, it was ridiculous," Myriam Nema said on Oct. 13. "10 minutes later, we came out, and we saw all the trees have fallen down."

The microburst also ravaged a mobile home park near Kyrene and Baseline roads.

"The covers were flying everywhere. A lot of AC units were falling off the houses," said one person.

"I thought I was in a tornado. [There are] no tornados in Arizona," said another person.

As of 2 p.m. on Oct. 14, roughly 200 Arizona Public Service (APS) and 200 Salt River Project (SRP) customers are still without power.

"I've lived here for over 22 years, I can definitely say I've seen some storms during my time, but this is absolutely the most extreme one that I've seen during my time here in Tempe or in Arizona," said Tempe Mayor Corey Woods.

Mayor Woods also said 70 businesses were impacted by the microburst, with about 63 of them located at Baseline Industrial Center.

"I was on a job, and we have some other fellow tenants here, and in a matter of minutes, I heard we need to go check on the warehouse," said Brian Trujillo.

Trujillo later found the roof of another building was peeled away by strong winds.

"It's a little unbelievable. [I was] born and raised in Arizona my whole life, so I hadn't really seen a storm cause that much damage before," Trujillo said. 

One day after the microburst, the city has gone from emergency response to recovery efforts. Meanwhile, some of the people affected by the microburst have sought refuge at the emergency shelter, looking for resources or a place to stay.

"This is going to be a while," said Terry Babcock, who lives in a Tempe apartment complex that was damaged during the microburst. "It's going to take more than just a day or two to fix this."

"We urge patience, though," said Mayor Woods. "Tempe is obviously over 40 square miles and totally landlocked, but at the same time, there was a record amount of damage that actually took place yesterday. So it's going to take some bit of time to really make sure that we can get all of this cleaned up and get everything restored."

What's a microburst?

Big picture view:

The NWS, on its website, defines microbursts as downdrafts, or sinking air, in a thunderstorm that is less than 2.5 miles (~4.02 km) in scale.

"Although microbursts are not as widely recognized as tornadoes, they can cause comparable, and in some cases, worse damage than some tornadoes produce," the website reads. "In fact, wind speeds as high as 150 mph are possible in extreme microburst cases."

Per the NOAA National Severe Storms Laboratory's website, there are two types of microbursts: wet microbursts, which comes with heavy precipitation at the surface, or dry microbursts, which comes with little to no precipitation reaching the ground level.

Why is it called "microburst"?

The backstory:

In an article published by the University of Chicago in October 2020, the term "microburst" was coined by a professor named Tetsuya Theodore "Ted" Fujita, the same man who is the namesake of a scale that is used to classify tornado strength.

Per the article, Fujita coined the term amid an investigation into a plane crash that killed 122 people in New York City in 1975. While other meteorologists were were initially skeptical, Fujita and his students traveled to various parts of the U.S. to collect evidence of the phenomenon, which helped establish that microbursts exists.

Where do microbursts form?

What they're saying:

The website pilotinstitute.com states that people are likely to encounter dry microbursts in western U.S. and the Great Plains region, while wet microbursts are common in the south, Midwest, and in the East.

Can meteorologists forecast microbursts?

What we know:

Depending on who you ask, the answer can be different.

Officials with NWS say forecasting for microbursts can be done, and they are typically done within six to 12 hours before microbursts are expected to develop.

The other side:

Conversely, officials with Gleim Aviation said microbursts are "impossible to forecast and difficult to detect."

"Since microbursts are so short-lived, they are difficult to detect as they may occur between radar scans. Although this system is helpful at times, microbursts can still occur with no warning at all," read a portion of their website.

Are microbursts dangerous?

Dig deeper:

Per NWS, microbursts can present danger to people, as wind speeds in microbursts can reach 100 mph (~160.93 km/h) or higher.

"Winds this high can cause major damage to homes and other structures and level hundreds of trees," officials wrote.

What should I do to stay safe when a microburst hits?

What you can do:

On their website, SRP officials said a very effective way to prevent power outage during a microburet is to keep trees clear of all power lines.

In addition, SRP officials advise that people should tie down loose items in their yard, or bring them inside as a way to minimize a microburst's impact on a home.