Pacific Hurricane Season Intensifies Under Strong El Nino
The eastern Pacific has seen an unusual number of powerful storms, while the Atlantic has been remarkably quiet.
The Pacific Ocean is experiencing an intense hurricane season, fueled by El Nino conditions that have emerged this year and are projected to persist into 2027. The phenomenon has led to warmer ocean waters and a significant increase in tropical storm activity in the Pacific.
University of Miami hurricane expert Brian McNoldy stated that the current El Nino is shaping up to be one of the strongest on record. The eastern Pacific has already surpassed its typical number of hurricanes for a full season. As of this week, Hurricane Polo brought heavy rain to Mexico's Pacific coast, fluctuating between Category 4 and 5 strength. In Hawaii, Hurricane Nolo poses a threat of catastrophic flooding.
During an El Nino, the trade winds across the Pacific weaken or reverse. This alters the jet stream, contributing to record global heat, severe droughts, wildfires, and dwindling water supplies. While El Ninos occur every two to seven years on average, their intensity varies. McNoldy predicts the current El Nino will peak in the coming winter and continue into 2027.
Conversely, El Nino conditions typically suppress hurricane activity in the Atlantic Ocean, which has been unusually quiet this year. Matthew Rosencrans, lead hurricane season forecaster with NOAA's National Weather Service, noted that both the eastern and central Pacific have seen four more tropical storms than average to date, with over two months remaining in the season.
From 1991 to 2020, the eastern Pacific averaged 15 named storms per season, which runs from May 15 to November 30. Reaching the yearly average in September is considered a notable deviation. This season has also seen three Pacific hurricanes reach Category 5 strength, tying a record set in 2002, another strong El Nino year.
The most active eastern Pacific season on record was 1992 with 25 named storms. For the central Pacific, the record is 14 in 2015. In 2015, the eastern Pacific recorded nine major hurricanes (Category 3 or higher), but no reported deaths. During that El Nino, storms tracked westward over open ocean.
Historical data shows the potential impact of strong El Ninos. In 1997, Hurricane Pauline caused hundreds of deaths in Mexico. Tropical Storm Nora brought unusual rainfall to Arizona, and a December storm in Southern California led to flooding and evacuations.
Hawaii has been particularly affected this year. Hurricanes Lala and Lowell in August and early September, respectively, caused significant damage to homes and public infrastructure. Governor Josh Green described the year's weather events as unprecedented. Nolo is expected to be the third hurricane to significantly impact the islands this year, potentially bringing rainfall measured in feet.
Meteorologists have raised concerns about "preparedness fatigue" in communities repeatedly facing storm threats. However, in Hawaii, the weariness stems from actual damage and ongoing recovery efforts amidst new threats. Residents are increasingly aware of the risks and the importance of self-sufficiency and community support during severe weather events.