Forecasters at NOAA announced Thursday that an El Niño has formed in the tropical Pacific Ocean.
The El Niño, which scientists for months have anticipated would arrive this summer, is predicted to reach a moderate or strong level this fall and a strong or very strong level in the winter.
El Niño is a natural cyclical warming of parts of the central Pacific and is declared by NOAA when temperatures are 0.5 degrees Celsius (0.9 degrees Fahrenheit) above average for several months. The ocean-warming phenomenon comes after the West Coast experienced a severe marine heat wave over the winter and spring, which has contributed to extremely high temperatures downstream across the United States and concerned scientists about disruptions to marine habitat conditions.
This summer, a majority of the U.S. will likely experience above-average temperatures, according to the Climate Prediction Center’s outlook for June to August. The greatest likelihood for hotter weather is in the Pacific Northwest through the Rockies, said a National Weather Service meteorologist and NOAA spokesperson.
