Preparing house for monsoon threats
We’ve gotten a bit complacent lately about the monsoon in Arizona – probably because we haven’t had much serious rainfall over the past 10 years.
But no one should take our monsoon potential for lightning, dust storms, heavy rain and flooding for granted.
“It’s true that 2011 was a down year for monsoon rain, but a few areas were hit really hard, like Carefree and Cave Creek and Queen Creek and Apache Junction,” said Royal Norman, chief meteorologist for Channel 3 (KTVK) in Phoenix. “But it is true that we’ve had less rain than usual in eight of the last 10 years.”
That’s because we have been in the middle of a strong La Niña period with lower-than-normal surface temperatures on the Pacific Ocean, a development that causes drought in Arizona and the Southwest.
The National Weather Service at this point predicts dry weather from now through the end of July.
“But we’re moving slowly toward El Niño (with higher surface temperatures on the ocean) which could mean more rain, but the downside could be more flooding,” Norman said.
Officially, the monsoon will start June 15 and end Sept. 30. Using these dates is a relatively new system, adopted in 2008. But it’s not as much fun as the old days, when the monsoon “began” as soon as we had three consecutive days with a 55-degree average dew-point temperature.
Typically, the monsoon takes place in summer when prevailing winds change, coming out of the south or southeast. This allows moisture from the Gulf of California and the Gulf of Mexico to stream into Arizona, where it interacts with cooler air at the state’s upper elevations to produce monsoon storms.
The monsoon is vital to Arizona’s water supply.
“It produces 30 percent of our moisture here,” Norman said, “and 50 percent in Tucson. In Douglas and Bisbee, it creates two-thirds of their annual rain. Generally, the farther south you go in Arizona, the more monsoon rain there will be.”
Flash floods are common during the monsoon season
Whether big, wet storms hit us or not, here are a few ways to prepare for these monsoon-related conditions:











