Odds of El Nino forming this summer increase – West Hawaii Today

An El Nino cycle is expected to begin this summer, though the strength of that cycle — and how it will impact Hawaii — is still up for debate.

El Nino cycles are defined by warming sea-surface temperatures in the central and eastern Pacific Ocean and weak tradewinds that push warm water east toward the U.S. West Coast and can change global weather patterns. Meteorologists have been warning of a possible El Nino, and “super El Nino,” in recent months, but climate modeling can only forecast so far ahead.

According to the latest update from NOAA’s Climate Prediction Center on Thursday, an El Nino cycle had an 82% chance of emerging between May and July and a 96% chance of continuing through December to February.

El Nino cycles don’t necessarily mean certain weather will happen, but it tips the scales of probability.

For Hawaii’s hurricane season, which lasts from June through November, El Nino cycles can make it more likely to have increased and more intense storms in the Central Pacific region. That likelihood only increases with stronger El Nino cycles characterized by even warmer surface water temperatures.

“Stronger events do not always mean bigger weather and climate impacts,” the Prediction Center clarified. “Stronger events can make it more likely that certain impacts could occur.”

As of Thursday, the Climate Prediction Center’s data showed it’s more likely for the majority Hawaii’s hurricane season to coincide with a more than 50% chance of weak El Nino conditions between May and August and a 24% chance of moderate El Nino conditions, or water temperatures between 1 and 1-1/2 degrees Celsius warmer than usual from June through August.

The El Nino cycle’s likelihood of strengthening increases through the winter, the prediction showed, with the three months at the tail end of hurricane season — September, October and November — having a 20% chance of being weak, a 31% chance of being moderate, a 26% chance of being strong with water temperatures between 1-1/2 and 2 degrees Celsius warmer than usual, and a 15% chance of being very strong with water temperatures more than 2 degrees warmer than usual.

In the three months leading to January, however, the strength of the El Nino cycle is a tossup, with a 15% chance of it being weak, a 26% chance of it being moderate or strong, and a 25% chance of it being very strong.

A stronger El Nino season in the winter and spring could mean even warmer and drier conditions are likely, Hawaii State Climatologist Pao-Shin Chu told the Honolulu Star-Advertiser, which can increase wildfire risk.

The August 2023 Lahaina wildfire was preceded by a strong shift from a La Nina cycle, which is characterized by cooler than usual surface sea temperatures in the Pacific, to a strong El Nino in July. Winds from a nearby hurricane exacerbated the fire’s reach in the arid area, killing 102 people and destroying more than 2,200 structures.

In the meantime, state and county emergency officials are encouraging all residents to be prepared for natural disasters. While an El Nino cycle doesn’t mean Hawaii will be hit with hurricanes or wildfires, it only takes one disaster to have catastrophic consequences.

The state Department of Commerce and Consumer Affairs Insurance Division is advising consumers to evaluate their insurance policies before hurricane season begins June 1, adding that most standard homeowners and renters insurance policies do not cover hurricane or flood damage.

Emergency officials said residents should have a plan of action, as most shelters across the state cannot withstand hurricanes beyond a Category 1 storm, which can generate sustained winds of 74 to 94 miles per hour.

Only three state buildings have completed or are undergoing hurricane retrofitting for up to a Category 3 storm with sustained winds of 111 to 129 miles per hour, Hawaii Emergency Management Agency information specialist Patrick Daley confirmed. Those are located in the Waialua High School gym on Oahu, the Molokai High School gym and the band room at Laupahoehoe Community Public Charter School, formerly Laupahoehoe High and Elementary School, on Hawaii Island.

Emergency officials said shelters should be a last resort and urged residents to retrofit their homes or seek refuge at another resident’s retrofitted home. Concrete buildings will be a safer option compared to wood buildings and residents should also have a two-week supply of necessities ready in the event of a disaster.

The University of Hawaii Sea Grant program offers a free handbook to help homeowners prepare for natural disasters on its website. The handbook also covers several retrofit measures to protect homes from hurricanes.