The Hawaiian Islands could face "catastrophic flooding" this week from a storm system moving over the archipelago, the National Weather Service in Honolulu said.
In an update Sunday, the weather service said a "kona low," a type of seasonal cyclone in the Hawaiian Islands, would linger just west of Kauai with a slow westward drift until Wednesday.
It warned that the storm could bring "widespread heavy rainfall...capable of producing catastrophic flooding, and strong southwest winds."
The weather service said early Monday that flash flood warnings continued for a number of areas, including Kaunakakai, Ualapu’e and Mauna Loa.
Meanwhile, a flash flood warning was extended for Maui, where video posted to social media Sunday night showed heavy rain.
A high wind warning was in effect for the summits of Mauna Kea and Mauna Loa on the Big Island through Monday morning, as well as over Haleakala on Maui. National Park Service employees observed winds of nearly 90 mph Monday on Haleakala.
A blizzard warning also remained in effect for the highest summits of Mauna Kea and Mauna Loa.
As residents across the islands braced for the storm, Hawaii County Mayor Mitchell Roth declared a state of emergency Sunday "due to the threat of imminent disaster."
Maui County public schools canceled classes Monday, and Kamehameha Schools, a private school system, said it would close its Hawaii Island and Maui campuses, preschools and offices.
In a Twitter thread Sunday, Gov. David Ige said preparations were underway for emergency officials to respond to any impacts.
"This storm has the potential to cause major flooding, landslides, road closures and damage to homes," Ige warned. "Now is the time to make sure you have an emergency plan in place and supplies ready should you need to move away from rising water."
He said residents should also "make sure that your neighbors have what they need as well, adding, “Our community is always stronger when we work together to ensure that we’re all protected."
The weather service said conditions were expected to start improving by late Tuesday, with drier air spreading into the western islands Wednesday.