Southwest Climate Outlook January 2009

January Climate Summary
Drought – A swath of abnormally dry conditions persists in the north and central parts of Arizona, while drought conditions are no longer present in west-central parts of the state. Most of eastern New Mexico is now classified as abnormally dry.
Temperature – Western Arizona has been mostly 4–6 degrees F colder than average, while eastern New Mexico has been mostly 2–4 degrees F warmer than average.
Precipitation – A series of winter storms moved across Arizona and northwestern New Mexico in the past 30 days. While most of Arizona received 100–400 percent of average precipitation, most of New Mexico received less than 50 percent of average.
ENSO – Sea surface temperatures cooled across much of the equatorial Pacific Ocean through December and early January, causing NOAA-CPC to declare a La Niña event.
Snow – Winter storms in December covered the higher elevations in many watersheds in Arizona and New Mexico with snow. On January 1, major river basins in Arizona had snow water equivalent (SWE) ranging between 131 and 334 percent of average; northern New Mexico had values of 100 to 175 percent of average.
Climate Forecasts – Forecasts show increased chances of above-average temperatures for much of the Southwest through June, and slightly increased chances of below-average precipitation for Arizona and New Mexico through May.
The Bottom Line – Recent winter storms should improve short-term drought conditions in Arizona and will be reflected in the February Southwest Climate Outlook. The recent development of a La Niña event suggests the total winter precipitation will be below average. These conditions likely contributed to near-average streamflow forecasts for the spring-summer despite the above-average early-season snowfall accumulations.