Home » February 2011 Southwest Climate Outlook
Published February 23, 2011
February 2011 Southwest Climate Outlook

Many prickly pear cacti around Tucson were nipped by frost in early February, severing many pads or causing the succulents to slump. Image source: Zack Guido, CLIMAS.

February 2011 Climate Summary

Drought– Exceptionally dry weather over the past 30 days has caused short-term drought conditions to expand and intensify across much of the Southwest. Drought conditions have intensified from moderate to severe levels across much of southeastern Arizona and southern New Mexico due to the continued dry spell.

Temperature– Several cold snaps have caused temperatures to be well below average in the past 30 days. Temperatures were 4–10 degrees F below average in eastern New Mexico and 0–4 degrees F below average in eastern and southern Arizona.

Precipitation– Scant precipitation fell in the Southwest between January 18 and February 16. The western half of Arizona and New Mexico generally saw less than 25 percent of average precipitation, with large swaths receiving less than 2 percent of average.

ENSO– The current La Niña event has shown some recent signs of weakening but still is at moderate strength. It is expected to continue impacting the winter weather pattern across the Southwest for the remainder of the winter season.

Climate Forecasts– Forecasts, largely influenced by recent warming trends and the expectation of a persisting La Niña event, call for warmer-than-average temperatures across the Southwest through the winter and spring and drier-than-average conditions into early spring.

The Bottom Line– The influence of the La Niña event is evident this month, as it has been since the winter began. January was a historically dry month for New Mexico, ranking as the driest January on record. As a result, drought conditions expanded across the region, with severe drought creeping into southern portions of both New Mexico and Arizona. Along with extremely dry conditions, a series of Arctic cold blasts sent temperatures plummeting below freezing, bursting water pipes, freezing vegetation, and wreaking havoc on other temperature-sensitive things. The La Niña event is expected to continue for the next few months, and as a result dry conditions are forecasted through the remainder of the winter. There are signs, however, that the La Niña event is weakening.

The Fifth IPCC Assessment Report off and Running

The Intergovernmental Panel on Climate Change (IPCC) is starting the preparation of the Fifth Assessment Report (AR5), which will be finalized in 2014. AR5, like its predecessors, is an international effort to synthesize peer-reviewed scientific studies. The current effort will draw on 831 climate experts who will summarize state-of-the-art climate science and climate change impacts, adaptation, and mitigation. New advances in science, including more realistic climate models, will introduce a whole new set of “what-if” scenarios of future climate projections, providing a more clear understanding of future climate in some cases while creating new uncertainties in others. Also new to the AR5 will be dedicated chapters on monsoons and El Niño–Southern Oscillation, as well as greater regional detail on climate change impacts, adaptation, and mitigation.

Previous reports have had important impacts in global and regional policy. AR1 in 1990 played a decisive role in leading to the United Nations Framework Convention on Climate Change. AR2 and AR3, issued in 1995 and 2001, respectively, helped lead to the Kyoto Protocol. AR4, published in 2007, was honored with the Nobel Peace Prize.