Southwest Climate Outlook April 2010

April Climate Summary
Drought– Drought conditions improved slightly again this month across the Southwest with much of southern Arizona and New Mexico classified as abnormally dry or drought-free.
Temperature– Cooler-than-average temperatures prevailed across much of Arizona and New Mexico again this month.
Precipitation– Very little precipitation was observed across much of the Southwest over the past 30 days as passing storms brought mostly wind and cooler temperatures.
ENSO– El Niño has dramatically weakened over the past month, with ENSO-neutral conditions expected to return later this spring or early summer.
Climate Forecasts– Seasonal climate outlooks point towards an increased chance of above-average temperatures across Arizona and New Mexico for much of this upcoming summer and a slightly increased chance of below-average precipitation fornorthern Arizona during the summer monsoon season.
The Bottom Line– El Niño weakened its grip on the weather pattern across the western U.S. this past month, letting storms track a bit farther north and with less sub-tropical moisture than was typical earlier this winter. This left much of Arizona
and New Mexico to contend with dry, breezy, and cool conditions as late-season winter storms tracked north of the region, ushering in cool air. Even with the recent dry spell, short-term drought conditions continue to improve and snowpack levels
remain high with the promise of delivering above-average streamflows to most basins in Arizona and New Mexico. Updated forecasts point towards a warm and possibly drier-than-average summer season, which may impact how fast and far short-
term drought conditions continue to improve, especially across drought-stricken portions of northern Arizona.