Arizona drought conditions to deepen through winter
By Shaun McKinnon, The Arizona Republic
25 September 2011
A dry winter and a weak monsoon fueled record wildfires, record heat and a succession of dust storms that played like a broken record, pushing Arizona deeper into a drought that has persisted since 1999. Now, forecasters say La Niña, the ocean force responsible for the scant snowfall in Arizona’s high country last year, has returned for an encore and could set the stage for even drier conditions next year. The latest weekly survey by the National Drought Mitigation Center in Lincoln, Neb., shows all of Arizona in some degree of drought, from abnormally dry conditions in the state’s western third to pockets of extreme drought on the Navajo Reservation and extreme and exceptional drought in the southeastern corner of the state. A winter forecast, meanwhile, by the Climate Prediction Center suggests little will change on the survey’s drought map in the coming months. The odds favor drier, warmer weather over most of Arizona through December. Dry conditions have forced some ranchers to continue reducing livestock herds already decimated by more than a decade of poor range conditions. Brittle forests contributed to a record wildfire season this year that has charred more than 1 million acres and lingered into September. San Carlos Lake near Coolidge is nearly empty, leaving less water for farmers in Pinal and Gila counties. […] Many climate experts say Arizona never emerged from a drought that began in the late 1990s, even though depleted in-state reservoirs refilled during occasional wet winters. Now, some climatologists suggest there could be a link between this dry cycle and other extreme weather events. “We’re seeing drought from Arizona to Georgia, unprecedented drought, but the thing that’s made it the worst ever in places like Texas, New Mexico and Oklahoma hasn’t been the rainfall deficit,” said Jonathan Overpeck, founding co-director of the University of Arizona’s Institute for the Environment. “It’s been the heat. We just haven’t had the clouds or the rain to cool the heat.” […]
The monsoon has proved troublesome for weather forecasters and climate experts because of its uneven behavior. Storms have skipped across the state with spotty results, in part because the high-pressure system that controls the direction of storms settled farther east then usual. “It hasn’t helped recharge the aquifers, and it hasn’t helped the rangelands,” said Nancy Selover, an Arizona State University geography professor and the state climatologist. “It makes the accumulation of moisture deficits worse. It’s going to be a tough year if it gets drier.” The dry conditions have taken their steepest toll this year on ranchers and farmers who depend on rain or rain-fed creeks or aquifers. Many still feel the effects of the longer drought, which forced ranchers to sell livestock and, in some cases, produce fewer crops. For them, the drought never really ended. Along the San Pedro River near Redington in Pima County, Stefanie Smallhouse helps run a ranch with her husband, Andy. Since the start of the current dry period a decade ago, they have reduced their cattle herds by about one-half as grass and other feed dried up on the range. “We’ve been waiting out the drought for about 10 years now,” she said. “You just don’t know when it will break. You hope it doesn’t break you.” […] So far, the effects of the resurgent drought are most obvious on the rangelands and in the forests, but another poor winter-runoff season could begin to draw down water supplies. The situation at San Carlos Lake, an agricultural reservoir near Coolidge, is already dire. The lake has shrunk to its lowest level in more than 20 years and, with less than 4,000 acre-feet in storage, it is precariously close to the minimum level needed to avoid massive fish deaths.
Water deliveries were cut off earlier this month, forcing farmers to dip into wells or to try to buy water from other sources, such as the Central Arizona Project, which delivers Colorado River water. […] “Arizona is on the front end of climate change,” UA’s Overpeck said. “In no other part of the country outside of Alaska are we seeing it more clearly. It’s going to get hotter, and we’re going to get less moisture.”
