UPDATE: 11:13 a.m.
A flood advisory is in effect for Oahu until 2:15 p.m. today due to flooding caused by excessive rainfall.
At 11:09 a.m., the radar showed heavy rain developing and traveling slowly eastward over Oahu.
“The heaviest rain is currently over the western half of the island, but is expected to fill in and move over the remainder of the island over the next few hours. Rain was falling at a rate of 0.5 to 2 inches per hour,” forecasters said.
Some locations that will experience flooding include Honolulu, Waipio, Mililani, Pearl City, Waikele, Wahiawa, Wheeler Field, Waipahu, Aiea, Kunia, Halawa, Waiahole, Waikane, Schofield Barracks, Salt Lake, Kahaluu, Moanalua, Ahuimanu, Iroquois Point and Ewa Beach.
Meanwhile, the flood advisories have been extended for Hawaii County and 1:45 p.m. and Maui County until 2:30 p.m.
At 10:30 a.m., the radar showed heavy rain moving over portions of the Puna and Kau coasts. Rain was falling at a rate of 1 to 2 inches per hour, with the heaviest rates of up to 3 inches per hour between Hawai‘i Volcanoes National Park and Pahoa, including portions of Pahoa Kalapana Road and Highway 11.
Some locations that will experience flooding include Hilo, Hawaii Volcanoes National Park, Volcano, Glenwood,
Mountain View, Wood Valley, Hawaiian Acres, Pahala, Orchidlands Estates, Keaau, Pahoa, Punaluu Beach, Kawa Flats, Papaikou, Naalehu, and Fern Forest.
At 11:04 a.m., the radar showed heavy rain over portions of eastern Maui. Rain was falling at a rate of 1 to 2 inches per hour with the highest rainfall rates in the upslope areas between Kaupo and Nahiku.
“While no significant impacts have been noted as of yet, additional rainfall over that area today is expected to produce more flooding concerns,” forecasters said.
The flood watch remains for all Hawaiian Islands.
EARLIER COVERAGE
A flood watch is in effect for all Hawaiian Islands today through Monday afternoon due to the possibility of flash flooding caused by excessive rainfall, according to the National Weather Service.
A deepening Kona low north of Kauai is expected to move southwest today and Monday before turning west. Thunderstorms and heavy showers will affect the region over the next couple days leading to the flash flood threat. Winds may strengthen to wind advisory levels Monday for lower elevations and high wind warnings on Hawaii island summits. Lingering moisture may keep rain over the state through the week.
>> Prepare for rainy weather as Kona low hits Hawaii
“Flood prone roads and other low lying areas may be closed due to elevated runoff and overflowing streams,” according to the forecast. “Urban areas may receive more significant flooding and property damage due to rapid runoff. Significant flooding may occur due to the overflow of streams and drainages. Landslides may also occur in areas with steep terrain.”
The greatest flood risk is along the southeastern mountain slopes of Maui and Hawaii counties as deep moisture spreads up the slopes.
The flood watch may be extended into Tuesday if weather conditions persist.
Flood advisories are also in effect for Hawaii County until 10:45 a.m. today, while Maui County will remain in effect until 11:30 a.m. today.
At 7:45 a.m. today, the Hawaii island radar indicated heavy rain traveling over portions of Puna and Kau coasts. Rain was falling at a rate of 1 to 2 inches per hour, with isolated heavier rainfall rates of 3 inches per hour between Pahala and Pahoa including areas of Pahoa Kalapana Road and Highway 11.
Some locations that will experience flooding include Hilo, Hawaii Volcanoes National Park, Volcano, Glenwood, Mountain View, Wood Valley, Hawaiian Acres, Pahala, Orchidlands Estates, Keaau, Pahoa, Punaluu Beach, Kawa Flats, Papaikou, Naalehu, and Fern Forest.
At 8:19 a.m. today, the Maui County radar showed heavy rain continuing to develop and move over the eastern portions of the island. Rain was falling at a rate of 1 to 2 inches per hour with the highest rates and totals found in the upslope areas between Kaupo and Nahiku.
Some locations that will experience flooding include Kipahulu, Kaupo, Hana, Haleakala National Park and Hamoa.