Aug 132014

By Tammy Gray

Despite some monsoon activity over the last month, drought conditions continue to worsen in Navajo County, with most of the region now classified as experiencing severe drought conditions.

The U.S. Department of Agriculture reported, “In northeastern Arizona, rain also continued to skirt much of the Navajo Nation and the Hopi Indian Reservation, leading to an increase in the coverage of severe drought.”

Although Navajo County is not alone in experiencing dryer overall conditions, much of the state has seen an improvement over the last month, with large portions of southern Arizona downgrading from severe to moderate drought between July and August.

Statewide, rangeland conditions have improved slightly, with 50 percent of rangelands and pastures categorized as being in poor to very poor condition at the beginning of August compared to 56 percent at the start of July.

The current drought has lasted nearly 15 years, making it the worst drought in the last 110 years that records for moisture conditions have been kept. According to the Smithsonian Institute, there is a chance the drought could continue for 20 or 30 more years. Researchers note that ancient tree rings indicate periods of drought that have lasted for decades, and even a century, at a time.

University of California paleoclimatologist B. Lynn Ingram believes that the conditions in the West are only unusual when compared to the 20th century. According to Ingram, conditions were milder and wetter than usual during most of the 20th century, which is also the period when the population exploded in the region. Ingram also warns, however, that moisture conditions can be unpredictable and the scales could just as easily tip toward sudden episodes of flooding as extended drought conditions.

As of Aug. 6, conditions throughout the state are slightly worse now than they were at this same time last year. In 2013, nearly 36 percent of the state was experiencing severe drought conditions. This year, that total is just under 59 percent. About 11 percent of the state is currently classified as experiencing extreme drought, while 28 percent is experiencing moderate drought, and two percent is abnormally dry.

In Navajo County, the only area that is not experiencing severe drought is a small southwestern section near Winslow. Previously, most of the southern portion of the county was classified as severe drought status, while the northern and western half had a moderate drought designation.

Conditions are expected to improve over the next three months, however, with the National Integrated Drought Information System (NIDIS) predicting improved conditions throughout most of Arizona by the end of October, including removal of drought designations in small portions of western Navajo County.

The Climate Assessment for the Southwest (CLIMAS) group reports improved conditions at most reservoirs and rainfall averages slightly above normal for the monsoon season.

“Many parts of Arizona received above-average precipitation last month thanks to monsoon rainfall,” a CLIMAS monsoon report notes. “The spotty nature of the monsoon, however, belies sweeping characterizations that apply to all regions because above and below-average rainfall is often experienced over short distances not captured by more sparsely located rain gauges.”

Weather stations in northern and central Navajo County reported rainfall between 50 percent and 75 percent of the average, while those in the southern portion of the county showed rainfall at around 25 percent to 50 percent above the average.