La Niña will dominate weather by year's end

Producers across the U.S. are probably quite familiar with the terms El Niño and La Niña, as seemingly every summer, at least a portion of the weather discussion through June and July revolves around these phrases. But what do they mean, and why do they impact summer weather across the U.S?

To start, let’s dive into what these terms are describing. El Niño and La Niña are the extreme phases of the ENSO cycle. The ENSO cycle, or El Niño-Southern Oscillation, is a recurring climate pattern that involves the temperature changes in waters of the central and eastern tropical Pacific Ocean.

The cycle doesn't have a set time frame, but generally lasts three to seven years before changing. When the cycles change, waters near the equatorial Pacific warm or cool by anywhere from 1 to 3 degrees Celsius.

The oscillating warming/cooling pattern directly affects rainfall distribution in the tropics, which can lead to a strong influence on summer weather in the U.S.

Most recently, we have been under the influence of the El Niño phase of the ENSO cycle, as water temperatures in and around the equatorial Pacific have been above average.

This has led to summer temps that have been relatively mild and has been mostly favorable for Midwest crop development. But forecasters see this pattern shifting to the other end of the spectrum...