UPDATE: Flood watch for Big Island extended, marine warnings issued

Update at 3:04 p.m. March 22, 2026: A flood watch has been extended until late tonight for Hawai‘i Island as rain from a Kona low storm leaves the Hawaiian Islands.

There are two marine warnings issued for the windward waters of the Big Island.

The first warning is for waters offshore of the Hāmākua Coast.

At 2:55 p.m., a severe thunderstorm capable of producing waterspouts was located just offshore of Pa‘auilo. The severe thunderstorm was moving northeast slowly, according to the National Weather Service in Honolulu.

The warning is in place until 4 p.m.

The second area is for waters offshore of the Ka‘ū coastline.

At 2:45 p.m., a severe thunderstorm capable of producing waterspouts was located near FAD Buoy RN, or near Pahala, moving east at 25 knots. This warning is in place until 4:45 p.m.

Update at 8:03 a.m. March 22, 2026: A flood advisory for Hawai‘i Island has been downgraded to a watch.

Radar shows that the heavy rain has diminished, according to the National Weather Service in Honolulu. The watch remains in effect until 6 p.m.

Stephen Parker, meteorologist with the National Weather Service, said rain is mostly over Maui County this morning, with the storm expected to slide southeast toward Hawai‘i Island later today, with rain starting tonight and lasting until Monday.

Update at 3:18 a.m. March 22, 2026: The flood advisory issued late Saturday night, March 21, for portions of the Big Island was extended and expanded as heavy showers lift north to cover the island.

The advisory is now in effect until 5:15 a.m. Sunday, March 22, and encompasses the entire Big Island.

National Weather Service radar indicated at 1:52 a.m. heavy showers around the island, with rain falling at 1 to 2 inches an hour. The heaviest rainfall is located over the southwest and southeast slopes of Mauna Loa.

Flooding of roads, poor drainage areas and streams because of excessive rainfall is expected.

The public is again advised to stay away from streams, drainage ditches and low-lying areas prone to flooding.

Story originally posted at 1:16 a.m. Sunday, March 22, 2026: A flood advisory is in effect for portions of the Big Island until 2:15 a.m. Sunday, March 22, because of flooding on roads and in poor drainage areas and streams expected cause by excessive rainfall.

National Weather Service radar indicated at 11:18 p.m. Saturday, March 21, that heavy rain was falling at 1 to 2 inches an hour over the southeast slopes of the Big Island, from Volcano to Nāʻālehu. Additional rainfall is also expected to move in over leeward Big Island from the west.

Some locations that will experience flooding include Hilo, Kailua-Kona, Hawaiian Paradise Park, Captain Cook, Waikōloa, Kapaʻau, Honokaʻa, Pōhakuloa Training Area, Pōhakuloa Camp, Volcano, Wood Valley, Glenwood, Hōnaunau, Hawaiʻi Volcanoes National Park, Honalo, Mountain View, Kāʻināliu, Kealakekua and Puʻu Anahulu.

The public is advised to stay away from streams, drainage ditches and low-lying areas prone to flooding.