Winter forecast: Warmer, wetter than normal for Southwest
Don't expect an end to the drought, though
KINGMAN - It looks like another warm winter in Arizona with above-average precipitation and a weaker-than-usual El Niño system, a national weather expert said Thursday.
The National Oceanic and Atmospheric Administration's Winter Outlook favors precipitation higher than normal from the southern half of California across the Southwest, South Central and Gulf states and along the eastern seaboard to Maine.
El Niño, the band of warm Pacific Ocean current that affects weather patterns in the southwest United States, should be developing over the next couple of months, said Mike Halpert, acting director of NOAA's Climate Prediction Center.
"While El Niño has yet to fully develop, it probably will start in the next week or so," Halpert said in a telephone conference with more than 20 reporters from all parts of the nation. "It will probably be weaker and persist into spring."
Every El Niño is different, and this one is "struggling to get going," he said.
Forecasters announced last week that the ocean and atmospheric coupling necessary to declare an El Niño has not yet happened. It has a 67 percent chance of developing by the end of the year.
Mohave County recorded between 6½ and 9½ inches of rain during a summer monsoon season that was wetter than usual. However, Halpert wouldn't even try to predict the amount of rain that Arizona could receive from El Niño.
"The entire Southwest is favored to have above-average precipitation. How much, we can't say. The monsoon was good with all of the cyclones and tropical storms forming on the Pacific," he said.
While drought conditions are expected to improve in some portions of the United States, California's record-setting drought will likely persist or intensify. Nearly 60 percent of California is suffering from "exceptional" drought - the worst category.
This year was a continuation of dry conditions from 2012, making it the driest three-year period on record, said Kevin Werner, NOAA's western regional climate services director.
Winter is the wet season in California, so mountainous snowfall will prove crucial for drought recovery. California's runoff period from winter snow was the shortest in a number of years, Werner noted, and the state's reservoirs are at 30 percent capacity.
Rainfall in the Northern Sierras this year was 31.3 inches, 63 percent of normal, while the central mountains in California received 20.3 inches, 50 percent of normal.
Turning to the Colorado River watershed, Werner reported that Lake Powell and Lake Mead are less than half full. In general, drought monitors are showing a downward trend in reservoir levels, with only four years above normal rainfall since 2000.
"It would take multiple years above average to get back to normal," Werner said. "Any one year is not going to fill those reservoirs, even if it is quite wet."
NOAA's temperature outlook favors warmer-than-average temperatures in the Western United States, extending from the West Coast through most of the Intermountain West and across the U.S.-Canadian border through New York and New England.
The rest of the country falls into the "equal chance" category, meaning there is not a strong enough climate signal in these areas to make a prediction, so they have an equal chance of being above, near or below normal temperatures.