Heavy rains diminish over East Hawaiʻi; flood threat shifts to west, north Big Isle

East Hawaiʻi finally got a reprieve — at least for now — from the threat of flooding after heavy rains diminished Friday night. Now, parts of the Big Island’s west and north sides are getting drenched.

A flash flood warning was in effect until 12:15 a.m. Saturday for portions of South Kohala, replacing an earlier flood advisory issued for the same area, when radar indicated just after 10:30 p.m. that heavy rain and thunderstorms were moving over the district.

Rain was falling at up to 3 inches per hour. Additional heavy rain was expected.

Areas that were to experience flooding included Waikōloa Village, Waimea, Puakō, Kawaihae, Puʻuanahulu, Kohala Ranch, Pōhakuloa Camp, Pōhakuloa Training Area, Waikii, Mauna Lani and Waikōloa Beach.

A flash flood warning was also in effect until 3 a.m. Saturday for locations in North Hawaiʻi after radar indicated at 11:48 p.m. Friday that heavy rain was falling over North and South Kohala and Hāmākua at a rate of up to 3 inches per hour.

The cluster of thunderstorms should be steadily moving northeastward.

Locations that will experience flooding include Kapaʻau, Honokaʻa, Waimea, Waipiʻo Valley, Waimanu Valley, Kukuihaele, Pololū Valley, Kawaihae, Kohala Ranch, Halaʻula, Paʻauilo, Hāwī, ʻŌʻōkala and Māhukona.

The West and North Hawaiʻi warnings were the latest to be issued Friday after heavy rains associated with a strong upper level disturbance drenched East Hawaiʻi earlier in the day.

Additional showers remained possible through Friday night.

A flood watch remains in effect for the entire state until 6 a.m. Saturday as heavy rain and strong to severe thunderstorms remain possible as the upper level disturbance continues to settle southward.

A winter storm warning also remains in effect until 6 a.m. Saturday for the summits of Mauna Kea and Mauna Loa on the Big Island, with heavy snow and very strong winds expected.

Total snow accumulation of up to 6 inches and winds gusting to more than 70 mph are forecast.

A high surf advisory for west and south shores of the island was also canceled at about the same time as the roughest of Friday afternoon’s weather struck.

A flood advisory for portions of Puna was canceled before rains moved into South and North Kohala, nearly 2 hours before it was set to expire at 10:15 p.m., after East Hawaiʻi was no longer threatened by flooding as heavy rains had diminished.

Locations that experienced flooding earlier in the day included Hilo, Hawaiian Paradise Park, Hawaiian Acres, Pāhoa, ʻŌʻōkala, Orchidland Estates, Volcano, Glenwood, Honomū, Hakalau, Nīnole, Laupāhoehoe, Hawaiʻi Volcanoes National Park, Eden Roc, Fern Acres, Kalapana, Fern Forest, ʻĀinaloa, Leilani Estates, Nānāwale Estates, Hawaiian Beaches, Isaac Hale Beach Park, Pepeʻekeo, Pāpaʻikou, Keaʻau, Wainaku, Paukaʻa, Kurtistown, Mountain View and Kapoho.

Parts of East Hawaiʻi were rattled Friday afternoon and nearly 6,000 Hawaiian Electric Co. customers, from Haihai Street to the Hilo Medical Center area in Hilo, lost power for about an hour as heavy rain and a strong thunderstorm bared down on the North and South Hilo and Puna districts.

Waiānuenue and Kamehameha avenues in Hilo were closed in both directions for a time because of flooding, and Hawaiʻi County Civil Defense warned other roads could be closed without notice.

The angry atmosphere calmed just before 5 p.m., with rain falling at a snail’s pace compared to just 2 hours earlier when 3 to 4 inches an hour soaked the Hilo area. The rain all but ceased about 30 minutes later.

Power was restored by about 4:50 p.m. to the majority of those in Hilo who lost it during the storm. At least one customer, however, continued to have issues even after getting their electricity back.

The Hele gas station and convenience store on Kaʻūmana Drive could only accept cash for transactions throughout the rest of its regular business hours Friday because of network issues caused by the outage.

The station’s ability to sell gas was also curtailed the rest of the day because none of its four gas pumps were able to reconnect to the network after power was restored.

A lone clap of thunder right before everything started to settle down gave you pause as to what might develop later in the evening. However, a flash flood warning was canceled after heavy rain moved offshore to the east of Hilo.

There was even sunlight shining through breaks in the gloomy, gray clouds still filling the sky at about 6:15 p.m.

The National Weather Service on Wednesday began issuing special weather statements about the storm system and the likelihood it would produce heavy rain and strong to severe thunderstorms as it settled into the islands from Thursday through Saturday.

The Big Island was forecast to see the brunt of the bad weather during the day and throughout the night Friday before the system is supposed to clear out Saturday.

A bunch of sunshine and bright blue skies shone through what you could still safely call mostly cloudy skies into the early afternoon in Hilo, making some people wonder if this would be one of those times when the weatherman might have gotten it wrong or the storm simply wasn’t going to be as bad as what meteorologists predicted.

It all started to change at about 2 p.m. or so as clouds thickened and the sunlight faded, replaced with a darker, more ominous hue.

Heavy rain began moving over the eastern slopes of the island at about 3 p.m., falling at 1 to 2 inches an hour in some places. That triggered a flood advisory for an area from ʻŌʻōkala to Hawaiʻi Volcanoes National Park.

The advisory was replaced with a flash flood warning about half an hour later as heavy rain intensified, falling at 3 to 4 inches an hour from Piʻihonua to downtown Hilo.

The strong thunderstorm dumped even more rain on Hilo starting by about 3:30 p.m., as Doppler radar tracked it moving northeast at 10 mph. It would stick around until just after 4 p.m., when it started moving toward Pepeʻekeo, Pāpaʻikou, Keaʻau, Wainaku, Paukaʻa and Kurtistown.

While it roared, the storm produced wind gusts of up to 50 mph, seemingly coming from every direction but south, and frequent cloud-to-ground lightning. It even shed half-inch hail.

Fortunately, no other issues caused by the bad weather had been reported as of late Friday night.

According to the National Weather Service Hawai’i Area Synopsis at 3:28 p.m. Friday, while the threat of thunderstorms decreases this weekend, plenty of lingering moisture combined with afternoon sea breezes and a broad surface trough nearby will support afternoon showers each day over interior and leeward areas of the islands.

The wet pattern could continue through the latter half of next week as another upper level disturbance approaches the state.