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SALT LAKE CITY — There's been a lot of flash flooding in Utah lately, and weather data backs that up. The National Weather Service in Salt Lake City has issued a record number of flash flood warnings during the last two years.
When a flash flood warning is issued for your area, it means you need to get to higher ground quickly. Safety is the mission of the National Weather Service when it comes to those warnings, which have become more frequent.
"We've had a very active monsoon season now for two consecutive summers," Alex DeSmet, a National weather service meteorologist said.
Damaging and life-threatening flood waters have washed through several Utah communities in the lower 2/3 of the state in recent weeks, and neighboring states.
So far this year, the NWS in Salt Lake City has issued 77 flash flood warnings. That's second only to the record number of flash flood warnings last summer, which was 118 year to date. That comes after 2019 and 2020, which some meteorologists dubbed "non-soon" years.
"There was simply little to no monsoon activity across the southwestern part of the United States," DeSmet said. "That only worsened our drought conditions."
The meteorologist said new research suggests this could be a new pattern when La Niña is in place in Utah and the surrounding region.
"Some of that emerging research points toward ... if you have a combination of a La Niña and below average winter snowpack preceding a monsoon season, a combination of those two things could mean a more active monsoon season is on the horizon," DeSmet said.
That's what Utah has experienced each of the last two years. A third straight year would be bad news for drought recovery. La Niña typically delivers above average winter precipitation in northern Utah, and below average precipitation in Southern Utah. So, this is a change.
Even though La Niña patterns have had a certain influence in the past, it doesn't necessarily mean that they will repeat in the future.
–Alex DeSmet, NWS meteorologist
But, the meteorologist said, no two La Niña episodes produce a predictable, reliable result. There can be a lot of year-to-year variability, and variability within a particular season, much like we saw last winter with both active and quiet periods.
"Even though La Niña patterns have had a certain influence in the past, it doesn't necessarily mean that they will repeat in the future," DeSmet said.
So, it will take more years of analysis to determine whether this is a trend.
The meteorologist also pointed out that advancements in satellite and radar technology lead to better detection of flooding. There's also greater awareness in the public, and more people sharing their observations.
"Most people have cellphones. They can take video of ongoing flash flooding," he said. "So there's greater detection capability and greater awareness capability."
That also leads to more flood warnings.
"Our focus is on the protection of life and property, and our mission is keeping people safe," DeSmet said.
That's why it's critical to check the forecast if you're heading into an area sensitive for flooding. If you see waters rise, turn around don't drown. It only takes 6 inches of water to sweep you off your feet and only a foot to start carrying away your car.
