Where has Hurricane Season Already Begun?

Hurricane Marie, Eastern Pacific Ocean (August 2014), Source: NOAA

Although hurricane season doesn’t begin in the Atlantic Ocean until June 1, it is already underway in the Eastern Pacific Ocean.  The area of the Pacific Ocean known as the “Tropical Eastern Pacific” is located north of the Equator, west of Mexico and east of Hawaii.  Hurricane season there starts two weeks earlier on May 15 and ends on the same date as in the Atlantic on November 30.

The National Hurricane Center in Miami monitors both the Atlantic Ocean Basin and the Eastern Pacific Ocean for tropical development.  That’s because systems that develop in both areas can affect the United States.  The Gulf Stream is a warm ocean current that allows tropical systems to maintain their intensity as they trek along the East Coast.  A good example of that is Hurricane Fran in 1996 that made landfall in North Carolina as a Category 3 hurricane.

On the West Coast of the United States the California Current has the opposite track of the Gulf Stream.  It keeps cooler water from the northern Pacific running along the California coast, which often precludes any tropical systems from making it that far north.  Tropical storms and hurricanes that form off the West Coast of Mexico can affect the United States in other ways such as creating rough surf when an intense storm develops.

The Eastern Pacific Ocean averages 15 named tropical storms, 8 of which become hurricanes and 3 of those become “major” hurricanes.  That’s compared to average in the Atlantic which are 11 named storms, 6 hurricanes and 2 “major” hurricanes.  A “major” hurricane is defined as at least a Category 3 on the Saffir-Simpson Hurricane Intensity Scale with sustained winds of at least 111 mph.  Although no named storms have developed yet this year in the Eastern Pacific Ocean, the Atlantic Ocean has already seen its first named storm of 2015.  Tropical Storm Ana made landfall in South Carolina on May 10 and brought heavy rain and winds.  The first named storm in the Eastern Pacific will be Andres.

While 2014 was a quieter than average season in the Atlantic Ocean, the Eastern Pacific Ocean had a much busier than average season.  The Eastern Pacific had 22 named storms, including 16 hurricanes of which 9 became “major” hurricanes last year.  In fact, the 16 hurricanes tied the Eastern Pacific record for most to develop in a season.  The most damaging Eastern Pacific hurricane last year was Odile, which made landfall in Cabo San Lucas, Mexico.

Mexico’s national weather organization, the Servicio Meteorológico Nacional, is calling for a busier than average 2015 season with 19 named storms, 11 hurricanes and 4 “major” hurricanes.  On the other end, tropical meteorologists at Colorado State University are calling for a below average hurricane season in the Atlantic Ocean with only 7 named tropical storms, 3 hurricanes and 1 “major” hurricane.