STORM WEEK: Flash flooding, drought concerns rising with warming climate

OMAHA, Neb. (WOWT) - Flooding is an often-overlooked aspect of storms.

According to the National Weather Service, flooding results in more deaths than any other kind of severe weather aside from heat.

The bad news is that flash flooding appears to be increasing as a threat.

“The biggest thing that I have noticed is that there is no time that you can’t get heavy rain anymore,” said Hydrologist David Pearson with the National Weather Service. “We’re seeing these heavy rains happen in months where they didn’t use to happen.”

A changing climate doesn’t only affect our temperatures. Pearson has seen precipitation impacted as well.

This is true both on the dry side of the scale that we have seen lately.

“It takes a long time to undo those extremes, especially on the dry side because it gets entrenched and becomes part of a larger scale pattern.”

Flooding — particularly flash flooding — is an issue that may be enhanced with the warming climate.

“As you get warmer, the idea is that that can enhance the amount of available moisture in the air.,” Pearson said. “So from a rainfall standpoint, when it does rain, you’ve got more moisture to work with and therefore, you can have those higher rainfall rates.”

One recent example cited by Pearson? The 2019 Heartland Floods.

A perfect storm of frozen ground, snow depth over a foot, a sudden surge in temperatures and a rainfall exceeding three inches led to widespread catastrophic flooding in our area.

“Moving forward, the thing to watch is those coincidental weather events could become more common because sort of, all bets are off now.”

Another example cited by Pearson was the Old Market flash flooding in 2021. On the evening of August 7th, thunderstorms dropped three to five inches of rain in just one hour over the metro. This caused a flash flood emergency downtown with water rescues and over $1 million in damage.

The carnage in the wake of this event’s heavy rainfall has even influenced how the National Weather Service approaches the lead up to future storms.

“If you are watching for heavy rain, then you are also thinking about that, okay, I’m watching for heavy rain but if it falls in downtown Omaha at the Old Market, this is what could happen.”

So as these extreme events increase - both for drought and flooding - the impacts will be felt by many. And it has already been felt by some.

This is why it is so important to know the meanings of different alerts, including those for flooding.

A flood watch is issued when conditions could become favorable for flooding to occur. You should use this time to plan on what you will do if flooding does happen.

A flood advisory is issued when minor flooding is happening that may be a significant inconvenience for you. This may involve high river levels or road closures. You should take action to avoid these areas.

A flash flood emergency refers to a life-threatening situation where action needs to be taken immediately. Heavy rainfall is leading to rapidly rising water; get to higher ground as soon as you can.

Use the 6 First Alert Weather App to get these types of alerts on your mobile device.

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