Much-Needed Monsoon Rains Arrive in the Southwest

By Samantha Kramer, AccuWeather.com Staff Writer
August 01, 2012; 8:46 PM
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August monsoons are expected to bring above-average rainfall to the state of Arizona. (Photo courtesy of Photos.com)

The annual southwest monsoons that can bring half of the region's annual rainfall with them have returned.

High temperatures, strong winds and high moisture have hit Arizona especially hard, and have also brought heavy rains to southeastern California and Nevada.

The rain provides relief for areas like Palm Springs, Calif., which received its first measurable rainfall, or more than 0.01 inch of rain, in more than three months on Tuesday.

But the rain that hits normally dry desert locations can also produce flash flooding. These flash floods have transformed San Bernardino, Calif., roadways into 6-inch-high streams and washed up mud and small rocks onto roads in southern Nevada.

"They can cause a lot of damage and are of concerns for just about anyone that lives near washes or streams or in poor drainage areas," said AccuWeather.com Expert Senior Meteorologist Ken Clark. "Water can come fast and furious and not even necessarily where it is currently raining."

Monsoon season in the Southwest usually begins in late June or early July, though the last two years have been a disappointment - sporadic, and not bringing the amount of rain that it should, Clark said. With El Niño developing this summer, however, this year could be different. The monsoon season is usually more active during El Niño than La Niña, he said.

The storms come as a double-edged sword, bringing much-needed relief to areas experiencing severe drought, but strong winds and dangerous lightning along with them. Currently, 94 percent of Arizona is experiencing severe to extreme drought conditions.

Thunderstorms can create strong downbursts and produce haboobs in dry areas. Phoenix, Ariz., has had seven haboobs - dust storms with dangerously high winds - so far this year, according to Severe Weather Expert Henry Margusity.

Arizona is experiencing severe drought conditions in 94 percent of the state. Last year at this time, only 37 percent of the state was in a severe drought. (Courtesy of the U.S. Drought Monitor)

August is expected to bring above-average rainfall to Arizona, according to AccuWeather forecasts, which will be much-needed relief for the state that was declared a natural disaster area to help farmers cope with damaged crops.

Yuma, Ariz., which usually only gathers 3 inches of rain per year, has already gotten almost 2 inches of rain for the month, which is 689 percent of the norm for July.

One flash flood in San Tan Valley, Ariz., claimed the life of a 2-year-old boy Sunday night.

Along with flash floods, the near-daily thunderstorms have also brought strong winds and lightning that have taken down power lines and trees in counties like La Paz, Ariz.

Clark said over the next few days, heavy rain will affect southeast California, western and northern Arizona, southern Nevada and parts of Utah, as well. He added residents should be on the lookout for flash flooding, strong winds and lightning that these thunderstorms can bring.

"Lives have been lost when people try to drive through water, and also people camping near usually-dry washes that fill quickly," he said.

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