HI-EMA urges public to prepare for Kona low storm

With high winds, high surf, thunderstorms and locally heavy rainfall expected to threaten the islands starting Sunday, the Hawai‘i Emergency Management Agency is urging members of the public to prepare.

The National Weather Service on Friday issued a special weather statement about the incoming “kona low” storm system expected to bring substantial hazards to the State. It described a “powerful low pressure system” that is expected to push across Hawai‘i on Monday, driving strong winds from the southwest, or kona, ahead of it.

“These strengthening winds may become damaging Sunday night and Monday. Impacts could include roof damage, downed trees, and power outages,” NWS reported. The incoming system also could generate thunderstorms with hail or locally heavy downpours, and snow, sleet or freezing rain is possible on the high mountain summits.
“A kona low system can bring strong gusty southerly winds across many areas that don’t usually experience them, and can easily damage roofs or send loose branches or other items flying,” said Luke Meyers, administrator of HI-EMA.

Big Island summits are expected to see Southwest to west winds of 45 to 55 mph, increasing to 70 to 100 mph Sunday night through Tuesday. Winds this strong can make driving and walking dangerous. The winds can forcefully open doors and damage hinges or slam doors shut, possibly causing injuries.

NWS also issued a winter weather watch for the summits above 12,500 feet, which could see heavy snow with accumulations of six inches. Gusty southwest winds of 70 to 100 mph are also anticipated.

Travel could be very difficult to impossible. Blowing snow will significantly reduce visibility at times, with periods of zero visibility.

A kona low system that struck the state in December 2021 caused millions of dollars in damage, including landslides on O’ahu and extensive flooding on Maui, and it may have contributed to a landslide that closed a road on Kaua‘i.

“With the holidays coming up, we encourage residents and visitors alike to plan any activities Sunday so they can be in a safe location by the time the storm’s effects start pushing ashore,” Meyers said.

While the storm appears relatively fast-moving and isn’t expected to cause widespread flooding, the locally heavy rain could cause localized flooding, road washouts or landslides, he noted. Residents should take steps to make sure loose items are stowed and branches that could damage property are trimmed before the high winds begin Sunday evening, and that nearby drainage culverts haven’t become clogged.

The weather system also is expected to push high swells onto north and west-facing shores from Sunday night through Tuesday, with waves affecting swimmers, boaters, and shoreline property. The swells could flood roads and coastal properties. HI-EMA will partially activate the State Emergency Operations Center on Sunday to monitor conditions as they evolve and to provide support to the counties and other partners if needed.

“We recommend that everyone in Hawai‘i take steps to prepare for the incoming system in case the impacts are significant, and at a minimum monitor reports as it gets closer to the State,” Meyers said.

Sources of reliable information include NOAA Weather radio and the emergency alert notification networks for each of Hawaii’s counties. Links to sign up for County alerts are available on the HI-EMA website at this link: https://dod.hawaii.gov/hiema/get-ready/