All Weather News

Eastern Pacific Hurricane Season Begins May 15

15 May 2021, 12:23 am


Although we have had our first named Tropical Storm (Andres) of the year in early May, May 15th marks the beginning of the Eastern Pacific hurricane season, which then lasts a full 200 days until the culmination on November 30th.

The average cumulative number of named storms (yellow) hurricanes (red) and major hurricanes (purple) in a calendar year for the Pacific Ocean. Credit: NOAA/NHC

Historically, the Eastern Pacific basin produces 15 named storms (winds 39 mph and greater) per year, of which 8 become hurricanes (74+ mph) and of which 4 become major hurricanes (111+ mph). You probably don’t hear much about most of these storms because history shows a majority of them form out to sea and remain out to sea. While the majority of these tropical cyclones form and remain over the open ocean, some bring impacts to land. Occasionally, southwest Mexico will experience torrential rain and mudslides from these storms. Sometimes a named storm will move through the Gulf of California (Sea of Cortez) and bring heavy rain to the Southwest United States. Lastly, a storm has been known to form in the eastern Pacific Ocean and travel west toward Hawaii (central Pacific Ocean) and then bring tropical impacts.

Historical tracks of tropical cyclones in the Atlantic and Pacific Ocean basins. Note: Most of the Pacific tropical cyclones remain out to sea, but some near land. Credit: NOAA/NHC

While the hurricane season begins on May 15 in the Pacific, the average first named occurs on June 10. The average first hurricane forms on June 26, according to satellite data used by the National Hurricane Center since the early 1970’s.

Climatology for Eastern Pacific tropical cyclones. Credit: NOAA/NHC

Last year, the Pacific hurricane season was about-average. There were 17 named storms, 4 hurricanes and 3 major hurricanes (average is 15, 8, 4 respectively).

About the author
Karissa is the Director of On-Air Operations at WeatherNation. Karissa grew up loving math and science, but really fell in love with Meteorology while attending the College of DuPage in Glen Ellyn, Illinois. After two summers of storm chasing in the central plains, she knew that it was the career path for her. Standing in front of a thunderstorm and feeling the cool outflow knock her over was an e... Load Morexperience she will never forget. After two years at COD, she transferred to Metropolitan State University of Denver. Karissa graduated Magna Cum Laude with a Bachelors of Science in Meteorology. Her high school and college speech and meteorology professors were extremely supportive and pushed her to succeed. Before joining the WeatherNation team, she previously worked as the Morning Meteorologist at KCAU-TV in Sioux City, Iowa and at WMBD-TV in Peoria, IL. She recently was part of a National Edward R. Murrow award winning team for breaking news for their coverage of the EF-4 tornado in Washington, Illinois. In her free time, Karissa enjoys cooking and trying new foods. She is a self proclaimed 'TV Junkie' who can get into just about any show. She is a die hard Chicago sports fan who loves attending professional sporting events.