Southwest Climate Outlook September 2009

September Climate Summary
Drought– Last month was the fourth driest August in Arizona in the last 116 years. On September 15, 90 percent of the state was classified as abnormally or moderately dry. In New Mexico, 45 percent of the state was abnormally dry or worse.
Temperature– The dry monsoon has provided no relief to the extremely warm conditions across the Southwest.
Precipitation– Recent monsoon activity in western New Mexico and central and eastern Arizona brought flash floods but no drought relief.
ENSO– An ENSO Advisory declared by the NOAA-Climate Prediction Center remains in effect this month. Weak to moderate El Niño conditions are expected to persist through the fall and early winter.
Climate Forecasts– Temperature forecasts call for increased chances of above-average temperatures in the Southwest throughout the remainder of 2009; precipitation forecasts state equal chances for above-, below-, or average precipitation.
The Bottom Line– Although Hurricane Jimena pushed moisture-laden air into the Southwest in early September, it was too little, too late. With the monsoon season officially wrapping up on Sept. 30, rainfall in most of Arizona and New Mexico has been below average. Scant precipitation caused drought conditions to expand, and some fear that if fall and winter precipitation is not at least average, drought impacts may become severe. Fortunately, El Niño conditions—which are forecast for fall and winter—typically bring above-average precipitation to the region.