News

Arizona Gets Ready for Another...Hurricane?

TERRY TANG

09/16/2014

PHOENIX (AP) — In a sign of just how unusual this summer's weather has become, Phoenix residents lined up Tuesday to fill sandbags in anticipation of potential flooding brought on by the remnants of a powerful Pacific storm.

It's the second time in two weeks that the desert is getting hit with the aftermath of a hurricane.

The forecast calls for the remnants of Tropical Storm Odile, which has been downgraded from a Category 3 hurricane, to strike hardest in the Tucson area over the next two days — although the Phoenix area expects to get lashed with rain and gusty wind, too.

Residents flocked to fire stations around Phoenix to get sandbags to place them around their homes as protection against floodwaters. Many experienced flooding last week after a storm dumped more than 5 inches of rain on parts of the state's largest city and turned two main freeways into rivers.

"It flooded my whole property, my horse pens, and my garage was under about 2 feet of water," said Roger Fuller, 72, who spent the morning loading up about 60 sandbags. "This time around, we're trying to keep the water off the property. Hopefully, it will work."

So what is going on to produce so much odd weather and cause people in Phoenix, of all places, to deal with the effects of back-to-back hurricanes? Here are answers to some key questions:

Q: ARE CONSECUTIVE HURRICANES IN SEPTEMBER UNUSUAL?

A: Yes. Jonathan Overpeck of the Institute of the Environment at the University of Arizona in Tucson said it's rare to have back-to-back events like this, and he noted that a third one could be brewing out in the Pacific. It's too soon to determine what factors have shaped this hurricane season. Scientists wait until the season is over in November before determining the causes of activity.

Q: IS CLIMATE CHANGE A FACTOR?

A: It's difficult to say whether climate change is a factor in one storm or one season of storms. But Overpeck said he would be amazed if climate change wasn't having some influence. Climate change can dramatically affect sea surface temperature and the atmosphere's capacity to hold moisture, creating ripe conditions for volatile storms. And Overpeck noted that large storms that dump record amounts of rain in a day or a few days are often a byproduct of climate change.

Q: ARE PACIFIC HURRICANES CAUSING MORE DAMAGE THAN THOSE IN THE ATLANTIC THIS SUMMER?

Yes. The Eastern Pacific season has 50 percent more active than usual, while the Atlantic is 50 percent less active. The result has been fierce storms striking Mexico in recent weeks, while the Atlantic had its first major hurricane — Edouard — form just this week.

Q: WILL ALL THIS RAIN HELP WITH ARIZONA'S DROUGHT?

Rain alone will not help refill reservoirs on the Colorado River. The current drought is drawing down Colorado River storage — in Lake Mead and Lake Powell in particular — to dangerous levels, Overpeck said. What is needed is a big snowpack in Colorado's Rocky Mountains. The snowmelt from snowpack is what fills reservoirs that supply drinking water. So, the upcoming winter, not hurricane season, is a crucial weather period.

Q: IS AN EL NINO PREDICTED THIS YEAR?

There will likely be an El Nino this year, albeit a weak one. An El Nino is a warming of the central Pacific once every few years, from a combination of wind and waves in the tropics. It shakes things up around the world, changing rain and temperature patterns. According to Overpeck, an El Nino will come in fall or winter but will be a moderate warming at the most. Climate observers were hoping for a stronger one to help with drought.