Tropical Storm Rosa Reminds Arizona of Its History of Jaw-Dropping Flash Floods

Tropical Storm Rosa is striking fear into the heart of Arizonans who know the damage major flooding can deliver in the desert, but Valley of the Sun residents are breathing a small sigh of relief after weather reports downgraded what had been a Category 3 hurricane to a tropical storm.

People across Arizona are staying on weather watch because the storm’s remnants, now expected to move into the state Tuesday morning, still are expected to pummel much of the state with heavy rains.

As of Monday morning, National Hurricane Center forecasters expect a moderate chance of flash floods in the southwest corner of the state but the entire state and beyond has some risk of flash flooding. In central and southern Arizona, 2 to 4 inches of rain is expected with some areas in the mountains receiving 6 inches; that mountain rainfall is what could be a worry.

Images and videos of darkened skies, blustering dust storms, rain and flooding across Arizona already had begun circulating on social media Sunday afternoon.

Arizona has a history of major floods.

The most recent was in 2014 when the Phoenix area was inundated with record-setting rainfall that flooded at least 200 homes in the Phoenix suburb of Mesa and turned Interstate 10 into a lake.

Sept. 8, 2014

In 2014, a massive storm fueled by the monsoon and a lingering Pacific Ocean hurricane surprised the Valley with record rainfall of up to 5.5 inches. Dozens of cars were stranded on I-10 after the freeway flooded.

When a pump system failed to kick in, a Mesa neighborhood turned into a river. More than 10,000 homes were without power, prompting then-Gov. Jan Brewer to declare a statewide emergency.

Damage and clean-up costs exceeded $18 million.

Jan. 19, 1993

The usually dry Salt River transformed into a raging, destructive waterway after multiple days of heavy rainfall.

The storm washed away shoring from the under-construction Mill Avenue Bridge in Tempe and sent tons of garbage down the river as the water reached a landfill. Eight people were killed and 112 injured, according to Arizona Republic archives.