 On May 23, the National Oceanic and Atmospheric Administration released its annual forecast, predicting a 70% chance of a near- to above-average season in both the Eastern and Central Pacific basins, with a total of 15–22 named storms, 8–13 hurricanes, and 4–8 major hurricanes.The reason for their outlook was the forecast of an El Niño to continue through the season, which reduces vertical wind shear across the basin and increases sea surface temperatures, favoring increased tropical cyclone activity.In addition, many global computer models expected a positive Pacific decadal oscillation (PDO), a phase of a multi-decade cycle that favored much warmer than average sea surface temperatures that had been ongoing since 2014 to continue, in contrast to the 1995–2013 period, which generally featured below-normal activity.