 The National Oceanic and Atmospheric Administration (NOAA) currently defines the season as starting May 15 in the eastern Pacific and June 1 for the central Pacific and ending on November 30 for both regions in each calendar year.Occasionally, however, storms develop in late November and persist until December, such as Hurricane Nina of 1957.Few off-season tropical cyclones in the east Pacific have affected land, and none of them have made landfall.