From the Cronkite News via Patch.com:
The U.S. Drought Monitor recently reported that, for the first time in its nearly 20-year history, none of the contiguous states was showing symptoms of severe or exceptional drought. That report includes Arizona, as this year’s abnormally wet May helped push the state out of a 10-year drought period.
According to the monitor’s weekly report for late last week, only 20.5% of Arizona was showing moderate drought or “abnormally dry” symptoms. Data for the same week in 2018 found 100% of the state in moderate drought or abnormally dry, with a majority of the state experiencing severe (97 percent) or extreme drought (73.2 percent).
Richard Heim, a meteorologist with the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information, said the change was tied to this year’s wet spring.
“Rain and snow have been falling in the areas that needed it, so the drought’s contracted a lot,” he said.
State climatologist Nancy Selover said the increased rain and snow came from winter storms over the Southwest that lingered longer and provided more moisture than in the past.
“Typically, that pattern stops in April, if we even get it,” Selover said. “Last year it was so dry, we never even got that pattern. … So it was really warmer than normal, really drier than normal. This year, we had what I would consider a more normal pattern.”
Heim said this kind of shift in drought status is normal for the desert. Although the U.S. Drought Monitor has been collecting data on drought since 2000, he said, such records as the Palmer Drought Index, with recorded data from as far back as the early 1900s, indicate that drought in Arizona ebbs and flows regularly.
Selover noted that the Drought Monitor’s map only reflects short-term drought, not long-term.
“In the western U.S., water resources is a long-term issue,” she said. “Reservoirs don’t fill in a year and aquifers don’t drain in a year or fill in a year. It takes multiple years that are dry or that are wet in order to change that.”