Update: Flood watch continues as threat of heavy rain persists over windward Big Island

Update at 8:37 a.m. Nov. 5: All flash flood warnings for the Big Island have either elapsed or been canceled; however, a flood watch remains in effect through this afternoon.

The National Weather Service forecast office in Honolulu says deep tropical moisture associated with a trough of low pressure will stall over the Kauaʻi Channel today and dissipate by this evening.

This, combined with a passing disturbance aloft, will maintain the threat for heavy rain,
flash flooding and the potential for a few thunderstorms, especially over windward portions of the Big Island and Maui.

Already saturated ground as well as streams and rivers overflowing from heavy rainfall Monday will only add to flooding concerns.

Flood-prone roads and other low-lying areas could once again be closed because of elevated runoff and overflowing streams.

Urban areas also might receive more significant flooding and property damage because of rapid runoff.

To keep up to date with any road closures, shelter openings or other information related to severe weather, check the Hawai‘i County Civil Defense Hazard Impact Map.

All county emergency shelters have been closed.

Hawaiʻi Police Department also reported that the portion of Highway 11 in Kaʻū previously closed Monday afternoon because of flooding, between the 57 and 62 mile markers, is now open.

Kamehameha Avenue in Hilo, between Ponahawai and Bishop streets, which also was closed Monday afternoon because of flooding, also is now open.

No other road closures were listed on the hazard map.

Update at 8:02 p.m. Nov. 4: The Na‘alehu Community Center emergency center is open, in addition to the Ka‘u District/Robert N. Herkes Gym and Kea‘au Armory shelters, according to Civil Defense.

Update at 7:39 p.m. Nov. 4: The National Weather Service has extended its flash flood warning for the island of Hawai‘i through 10:45 p.m.

Radar and automated rain gauges at 7:39 p.m. indicated heavy rain over primarily windward, southeast and interior portions of Hawai‘i Island. Rain was falling at a rate of up to three inches per hour.

This is leading to significant rises in water levels in streams and rivers, with stream gauges at Honoliʻi Stream and Wailuku River exceeding the minor flood stage of 15 feet and 18 feet, respectively. Flash flooding is ongoing or expected to begin shortly.

Update at 5:53 p.m. Nov. 4: Big Island police report that Highway 11 in Kaʻū, between the 57 and 62 mile markers, is closed because of flooding. No alternate routes available.

Update at 5:23 p.m. Nov. 4: The National Weather Service has extended the flash flood warning for the Hawai‘i Island districts of Kaʻū, North Hilo, Puna and South Hilo through 7:30 p.m.

A flash flood warning means that flooding is imminent or occurring.

The Department of Transportation has closed Highway 11 between the 57 and 62 mile markers (Kawa Flats) due to water on the roadway. Additional road closures can be found on the Civil Defense Hazard Map or by calling Civil Defense at 808-935-0031.

The Kaʻū District/Robert N. Herkes Gym and Kea‘au Armory evacuation shelters are open.

Update at 4:58 p.m. Nov. 4: The National Weather Service has issued a new flash flood warning for a larger area of the Big Island in effect until 7:30 p.m.

Some locations that will experience flash flooding include those covered by the previous flash flood warning such as Hilo, Hawaiian Paradise Park, Glenwood, Hawaiʻi Volcanoes National Park, Wood Valley, Mountain View, Pahala, Hawaiian Acres, Keaʻau, Punaluʻu Black Sand Beach, Orchidland Estates, Pāpaʻikou, Pepeʻekeo and Honomū as well as others such as Volcano, Honokaʻa, Pōhakuloa Training Area, Pōhakuloa Camp and Kawa Flats.

Radar indicated heavy rain at 4:33 p.m. over primarily windward, southeast and interior portions of the Big Island. Rain was falling at a rate of up to 3 inches per hour, and up to 7 inches of rain had fallen since this morning in some areas.

This is leading to significant rises in water levels in streams and rivers. Flash flooding is ongoing or expected to begin shortly.

Flooding is possible in drainages, streams, rivers, roads, properties and other low-lying areas. Public road closures are possible in some areas. Landslides are also possible in steep terrain.

The public is advised to stay away from streams, rivers, drainage ditches and culverts, even if they are dry now.

Do not cross fast flowing or rising water in your vehicle, or on foot. Turn around, don’t drown.

Update at 4:19 p.m. Nov. 4: Big Island police report that heavy rain in Puna is causing water to run off and pond on roadways, primarily Highway 130 in Keaʻau and Highway 11 in Mountain View and Glenwood.

Motorists are urged to drive with extreme caution and avoid unnecessary travel until weather conditions improve.

Kamehameha Avenue, between Ponahawai and Bishop streets, in Hilo is also closed because of flooding.

The public should avoid the area and use alternate routes.

A flash flood warning continues for windward areas of the Big Island until 5 p.m. and a flood watch is in effect through tomorrow.

Update at 1:42 p.m. Nov. 4: The flash flood warning in effect for east and south areas of the Big Island has been extended until 5 p.m. as heavy rains are forecast to continue.

Radar indicated heavy rain at 1:34 p.m. over eastern Kaʻū, Puna and Sout Hilo, continuing to fall at a rate of up to 4 inches per hour and Honoliʻi Stream and Wailuku River on the rise.

Flash flooding is ongoing or expected to begin shortly in the warning areas.

The locations that will experience flash flooding are the same as in the previous alert message.

Update at 12: 22 p.m. Nov. 4: A flash flood warning is in effect until 2 p.m. for several east and south areas of the Big Island, replacing the previous flood advisory that was in effect.

Some locations that will experience flash flooding include Hilo, Hawaiian Paradise Park, Glenwood, Volcano, Mountain View, Hawaiian Acres, Hawaiʻi Volcanoes National Park, Keaʻau, Orchidland Estates, Pāhoa, Pāpaʻikou, Pepeʻekeo, Honomū, Wood Valley, Hakalau, Pāhala, Laupāhoehoe, Punaluʻu Black Sand Beach and ʻŌʻōkala.

Radar indicated heavy rain at 12:05 p.m. over eastern Kaʻū, Puna and South Hilo, falling at a rate of up to 4 inches per hour.

Honoliʻi Stream and Wailuku River continue to rise.

Flash flooding is ongoing or expected to begin shortly in drainages, streams, rivers, roads, properties and other low-lying areas.

Public road closures are possible in some areas. Landslides are possible in steep terrain.

The public is advised to stay away from streams, rivers, drainage ditches and culverts, even if they are currently dry. Do not cross fast-flowing or rising water in your vehicle or on
foot; turn around, don’t drown.

Original post at 10:22 a.m. Nov. 4: A flood advisory is in effect until 1 p.m. for several east and south areas of the Big Island because of heavy rainfall.

Some locations that will experience flooding include Hilo, Hawaiian Paradise Park, Glenwood, Volcano, Mountain View, Hawaiian Acres, Hawaiʻi Volcanoes National Park, Keaʻau, Orchidland Estates, Pāhoa, Pāpaʻikou, Pepeʻekeo, Honomū, Wood Valley, Hakalau, Pāhala, Laupāhoehoe, Punaluʻu Black Sand Beach and ʻŌʻōkala.

Minor flooding on roads and in poor drainage areas and streams can be expected.

National Weather Service radar indicated heavy rain at 9:48 a.m. falling at a rate of up to 2 inches per hour over south and east portions of the Big Island.

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