Southwest Climate Outlook November 2009

Date issued

November Climate Summary
Drought– Drought conditions decreased in Arizona and increased in New Mexico during the last 30 days. More than 50 percent of Arizona and 69 percent of New Mexico remain drought free. The Four Corners region has been the hardest hit area.
Temperature– The water year continues to be warmer than average, in spite of a few cold snaps brought on by passing storms. Average temperatures in the last month also have been generally above average.
Precipitation– Storms that have passed through the Southwest since the water year began have wafted northeast, clipping only northwest Arizona. Most of Arizona and New Mexico have been drier than average in the last month and since the water year began.
ENSO– The La Niña event remained at moderate to strong strength during October. Cool water beneath the sea surface and enhanced trade winds from the east likely will help sustain the strength of the event through the end of the year. There is more than a 92 percent chance that La Niña will persist through the January–March period.
Climate Forecasts– Probabilities for warm and dry conditions in many parts of the Southwest are greater than 50 percent through the winter and early spring.
The Bottom Line– Warm and dry conditions prevailed during the last month and could be a harbinger for future months. Althought these conditions helped expand drought in New Mexico, most of the Southwest is drought free. The moderate to
strong La Niña event likely will grab future headlines, as it is projected to continue into the spring and these events often direct storms north of the Southwest, leaving the region dry. Many forecasts call for expanding drought conditions and below-average rain and snow. There is some indication that the La Niña event is nearing its peak strength, but it’s also possible that it will intensify. A dry winter could cause Lake Mead to drop below a critical water elevation and trigger additional releases from Lake Powell to temporarily stave water rationing in the Lower Colorado River Basin.

Published by the Climate Assessment for the Southwest (CLIMAS), with support from University of Arizona Cooperative Extension, the Arizona State Climate Office, and the New Mexico State Climate office.

Disclaimer. This packet contains official and non-official forecasts, as well as other information. While we make every effort to verify this information, please understand that we do not warrant the accuracy of any of these materials. The user assumes the entire risk related to the use of this data. CLIMAS, UA Cooperative Extension, and the State Climate Office at Arizona State University (ASU) disclaim any and all warranties, whether expressed or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will CLIMAS, UA Cooperative Extension, and the State Climate Office at ASU or The University of Arizona be liable to you or to any third party for any direct, indirect, incidental, consequential, special or exemplary damages or lost profit resulting from any use or misuse of this data.