Precipitation

Precipitation since the water year began on October 1 ranges from more than 130 percent of average in the northwest corner of Arizona to less than 25 percent of average in the southeastern corner of New Mexico (Figures 1a–b). Most of Arizona and northwestern New Mexico have received 25–90 percent of average precipitation. The southeastern half of New Mexico, however, has received less than 50 percent, with the driest conditions occurring in the southeastern corner. The dry conditions began in the winter during the moderate to strong La Niña event that helped push storms to the north. For most of the Southwest, monsoon precipitation has been below average. The exceptions have been in southeastern Arizona and the Four Corners region where rainfall since June 15 has been above average (see page 12).

In the past 30 days many regions in New Mexico and Arizona have received more than 130 percent of average precipitation, though large dry areas stretch across the Southwest (Figures 2c–d). The copious precipitation came during a wet week, when a low pressure system helped create favorable conditions for widespread and heavy monsoon precipitation. The recent rainfall in southeastern Arizona and southwestern New Mexico has brought some relief from exceptional short-term drought in both states. However, as has been the story in the last year, the southeastern third of New Mexico generally has been dry, receiving between 5 and 50 percent of average precipitation.