Hurricane Nolo could cause “catastrophic” flooding in Hawaii, forecasters warn

Hurricane Nolo strengthened into a Category 2 storm as it approaches Hawaii as a potential “catastrophic” rainmaker, the National Hurricane Center said, and is expected to grow stronger throughout the weekend. 

The storm was nearly stationary on Saturday morning, the NHC said. It is forecast to move westward with increasing speed later Saturday and Sunday. It is expected to strengthen into a major hurricane later Saturday or early Sunday before weakening on Monday.

A hurricane watch is in effect for Hawaii County due to the storm, which could dump up to 3 feet of rain on Hawaii’s Big Island. Catastrophic and life-threatening flash flooding is possible on the Big Island into this weekend, forecasters warn. 

President Trump on Friday approved an emergency declaration for Hawaii that will provide federal resources and assistance to the state in its recovery from Nolo, Hawaiian Gov. Josh Green said.

“Don’t venture out if you don’t have to into the dangerous flooding environment, but also high winds. We can have trees and power lines down,” Michael Brennan, director of the National Hurricane Center, said Friday.

The center of the storm was hundreds of miles from Hawaii as of Saturday morning and is expected to stay “well south and southwest” of the main Hawaiian Islands. But hurricane-force winds were extending outward up to 45 miles from Nolo’s core and tropical storm-force winds extended outward up to 140 miles.

Nolo had maximum sustained winds near 100 mph, making it a Category 2 hurricane. The Miami-based hurricane center said it is expected to keep strengthening and become a major hurricane this weekend, which is defined as a Category 3 hurricane or stronger.

A tropical storm warning is in effect for Hawaii County (in addition to the hurricane watch there), and a tropical storm watch is in effect for Maui County. 

The Big Island began to experience tropical storm conditions Friday night, forecasters said, with hurricane conditions possible for the island Saturday, especially in areas with steep terrain.  

Nolo could bring up to 25 inches of rain to the eastern and southern portions of the Big Island. That much rain could trigger “catastrophic life-threatening flooding and mudslides, especially in areas of steep terrain,” the hurricane center warned Friday.

The Big Island’s western areas could see 2 to 4 inches of rain and 8 at most. For Maui, 4 to 6 inches is possible with as much as 10 inches in some spots. The rest of Hawaii is likely to get 1 to 3 inches and 5 at most, enough to set off isolated flooding, forecasters said.

All state parks on the Big Island and on Maui will be closed because of the storm, the state’s Department of Land and Natural Resources said. 

Nolo formed as another storm, Hurricane Polo, continued to swirl in the Pacific, off Mexico’s southwestern coast.

The latest storms add to an unusually active season in the Pacific. Earlier this month, Hurricane Lowell brought damaging winds and heavy rain to the western Hawaiian islands of Kauai and Niihau, bringing down trees, damaging roads and knocking out power for thousands.

Last month, Hurricane Lala washed away about 100 homes, triggered landslides and caused widespread power outages as it brushed past Hawaii.