El Niño is so 2015.
Order is restoring in the Pacific Ocean, after one of the strongest El Niño events ever recorded (regardless of impacts on Arizona). That order may be short lived, as there are signs the Pacific shifts from normal to La Niña. Instead of warmer than normal waters in the eastern Pacific, cooler sea surface temperatures (SST for short) prevail. In other words, it’s the opposite of El Niño.
So when could La Niña impact southern Arizona? Latest climate models hint at a slight La Niña flavor by late Fall into Winter. As far as what it means for rain & mountain snow, La Niña tends to bring less during that timeframe. Not a hard & fast rule, but it certainly increases the odds of a dry Fall/Winter.
That being said, it may not matter. At first glance, the potential developing La Niña looks to be weak, meaning SST’s are less than or equal to 0.5° below average. If the long range outlook verifies, La Niña could have little impact on our weather late in the year. As I always say with a forecast this far out, a lot can & probably will change. We’ll keep you posted.