Precipitation: May and June historically are the driest months in the Southwest, and in the last 30 days rainfall in most of Arizona was nil. However, a storm wafting in from the Gulf of Mexico delivered copious rain in parts of eastern New Mexico. Since mid-December, precipitation in most of Arizona and New Mexico has been less than 50 percent of average.
Temperature: In the last 30 days, temperatures were above average in nearly all of Arizona and New Mexico. Anomalies were highest in southern Arizona and New Mexico. In southern Arizona, temperatures were 4–8 degrees F warmer than average. Temperature anomalies at night (i.e., the daily low temperature) were slightly higher than day anomalies, likely because of increases in humidity in recent weeks.
Water Supply: Total water stored in Arizona and New Mexico reservoirs increased in May. In Arizona, storage in Lake Powell increased by about 1.1 million acre-feet (AF), while Lake Mead declined by about 600,000 AF. In New Mexico, total reservoir storage is at about 25 percent of capacity, and storage in Elephant Butte is at 17 percent of capacity. Due to the low levels, water allocated to irrigators in the Elephant Butte Irrigation District will receive only 6 inches of water per acre, 30 inches below a full allocation.
Drought: About 76 and 85 percent of Arizona and New Mexico, respectively, are experiencing at least severe drought. In the last four weeks, drought largely remained the same in Arizona but improved in northeastern New Mexico. Drought intensity remains relatively unchanged in Arizona and less intense in New Mexico compared to one year ago.
ENSO: Although ENSO-neutral conditions continue, there is a 70 percent chance an El Niño event will develop during the summer. The ultimate strength of the event is still uncertain, but several indicators of an El Niño have weakened in recent weeks, suggesting that a strong event may not be materialize.
Precipitation Forecasts: Numerous climate models forecast an increased chance for wetter-than-average conditions during the monsoon for Arizona and New Mexico. This forecast may reflect increased chances for East Pacific tropical storm activity, which can inject moisture into the Southwest.
Temperature Forecasts: Precipitation in the summer can suppress temperatures by increasing evaporative cooling and cloud cover. With elevated chances for above-average precipitation, forecasts call for equal probabilities for above-, below-, and near-average temperatures.
Fire Forecasts: The number of acres burned this year has been above average in Arizona and below average in New Mexico. For the next month, fire risk is above normal in most of both states; fire activity in the Southwest is highest in June and July.