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Thunderstorms, heavy downpours could be in store for isles

Gordon Y.K. Pang
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DENNIS ODA / DODA@STARADVERTISER.COM

People protect themselves from the rain with umbrellas as they cross King Street in downtown Honolulu on Wednesday.

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NATIONAL WEATHER SERVICE

This composite radar image taken at 4:45 a.m. showed heavy rain over East Maui.

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CRAIG T. KOJIMA / CKOJIMA@STARADVERTISER.COM

Johan Tran, middle, and Lincoln Roshi walked down Pali Highway on their way to the YMCA Wednesday.

Update 4:30 p.m.

Forecasters say there is a chance for more wet weather over the islands through Friday as a flash flood watch remains in effect.

A moist airmass moving over the islands combined with a nearby upper level disturbance could bring thunderstorms with heavy downpours over the islands tonight and Friday.

A flash flood watch remains in effect for all islands, except Kauai, through Friday afternoon.

Update 8 a.m.

The flash flood warning for Oahu has been canceled.

Radar showed that heavy rains that had been soaking Oahu this morning have ceased, weather officials said.

A flash flood watch remains in effect for all islands, except for Kauai, through 6 p.m. Friday.

The city opened its emergency operating center at 6 a.m., but closed it at 7:55 a.m. after the National Weather Service canceled the flash flood warning.

The National Weather Service’s automated rain gauges reported at 7 a.m. the heaviest downpour occurred in Nuuanu and Manoa.

During a three-hour period beginning a 4 a.m., 2.82 inches fell at Manoa Lyon Arboretum, followed by 2.27 inches collected in upper Nuuanu.

Moanalua rain gauges reported 1.41 inches followed by 1.06 inches at Waiawa.

Since 7 a.m. Wednesday, 4.58 inches was recorded at the Lyon Arboretum rain gauge, followed by 3.54 inches in upper Nuuanu.

City Emergency Management and fire officials said no major problems were reported overnight.

Update 5:30 a.m.

Weather officials posted a flash flood warning and flood advisory for Oahu this morning.

Radar at 5:22 a.m. showed heavy rain across Honolulu and the crest of the Koolau mountains on East Oahu, according to the National Weather Service.

The warning is in effect though 8:15 a.m. and the advisory is in effect through 8:00 a.m.

Locations in the warning include, but are not limited to, Honolulu, Maunawili, Kailua, Waikane, Hawaii Kai, Salt Lake, Kaneohe, Waiahole, Moanalua, Halawa, Kaneohe Marine Base and Waimanalo.

The earlier flash flood warning for the island of Maui has expired.

Update 4:30 a.m.

A flash flood warning is in effect for the island of Maui through 5:30 a.m. this morning.

At 4:17 a.m., officials at the National Weather Service saw heavy rain gradually diminishing over portions of Maui. However, stream gauges showed a rapid rise in water levels over the last hour.

There is a landslide on Hana Highway between mile markers 14 and 15, according to Maui Civil Defense.

Locations in the flash flood warning include, but are not limited to, Windward East Maui between Nahiku and Kipahulu and Windward West Maui between Kahakuloa and Waiehu, including Honokohau, Pauwela, Huelo, Kaupo and Waiehu.

Flood advisories have been issued for Molokai and Hawaii island through 7:15 a.m. and 6:15 a.m., respectively.

An earlier flood watch for all islands, except Kauai, has been extended through Friday afternoon.

Update Thursday 1:37 a.m.

The National Weather Service issued a flood advisory for Maui until 4:15 a.m.

Radar at 1:17 a.m. showed heavy showers and thunderstorms rapidly developing over east Maui from Huelo to Kipahulu with additional showers and storms approaching from the east.

Rainfall rates greater than 2 inches per hour will fall over already saturated areas which will quickly develop runoffs, forecasters said.

Locations of the advisory include but aren’t limited to Haiku-Pauwela, Kaupo, Pauwela, Kipahulu, Huelo, Nahiku, Hana, Kailua, Wailua, Hamoa and Haleakala National Park.

Rainfall and runoff will also cause hazardous driving conditions due to ponding. Forecasters urge the public to stay away from streams, drainage ditches and low lying areas.

Update 10:15 p.m.

The National Weather Service canceled a flash flood warning for the Big Island, but a flash flood watch is still in effect until Thursday afternoon.

The flash flood watch includes Oahu, Kahoolawe, Lanai, Maui, Molokai and the Big Island.

Abundant tropical moisture will continue the threat of heavy rainfall and flooding, forecasters said.

Update 8:30 p.m.

Heavy rain continued across portions of Puna and Kau districts but has diminished across Hamakua and Hilo districts. A flash flood warning remains in effect for the Big Island until 10:15 p.m.

Rain continued to fall at a rate of up to 2 inches per hour near Volcano and Pahala. The areas of heavy rain are nearly stationary.

Locations in the warning include, but are not limited to, Hilo, Hawaiian Paradise Park, Keaau, Pahoa, Pahala, Glenwood, Hawaiian Acres, Kawa Flats, Mountain View, Volcano, Hawaii Volcanoes National Park and Orchidlands Estates.

Update 7:25 p.m.

A flash flood warning for the Big Island has been extended until 10:15 p.m.

Radar at 7:17 p.m. indicated heavy rain across numerous areas within Hamakua, Hilo, Puna and Kau districts.

Rain was falling at a rate of up to 2 inches per hour, and areas of heavy rain were nearly stationary.

Locations in the warning include, but are not limited to, Hilo, Hawaiian Paradise Park, Honokaa, Honomu, Keaau, Waimanu valley, Waipio valley, Pahoa, Pepeekeo, Pahala and Glenwood.

A flood advisory was also issued for Maui until 9:45 p.m.

Radar at 6:40 p.m. showed developing showers and thunderstorms over windward east Maui. Showers were especially heavy over Kaupo and Kipahulu, with other heavy showers affecting the Hana Coast between Hamoa and Haiku.

Rainfall rates were between 1 to 2 inches per hour with these slow-moving showers.

Locations in the advisory include, but are not limited to, Pauwela, Kipahulu, Huelo, Nahiku, Haiku-Pauwela, Kaupo, Makawao, Kula and Hana.

Update 5:15 p.m.

A flash flood warning was issued for the Big Island until 8 p.m.

Radar at 5:07 p.m. indicated heavy rain and thunderstorms along the Hamakua Coast. Rain fell at a rate of 3 to 4 inches per hour.

Locations in the warning include, but are not limited to, Honokaa, Honomu, Kukuihaele, Papaikou, Waimanu valley, Waipio valley, Ookala, Laupahoehoe and Paauilo.

Previous coverage

Despite a mid-afternoon lull from the steady showers that saturated the state in recent days, the National Weather Service’s flash flood watch remains in place for Oahu, Maui, Molokai, Lanai and Hawaii island through 6 p.m. Thursday.

“There’s still the potential, given the instability associated with the upper trough over the state, that things could fire back up,” said Matt Foster, weather service meteorologist. “I’m kind of surprised, given the time of day, that it did kind of weaken, but there’s still a lot of moisture upstream, there’s still tradewinds that are going to be coming in, pushing it over us. We’re going to at least keep it going tonight and see what happens.”

There continue to be several, isolated thunderstorms on Hawaii island this afternoon, Foster said.

In addition to the flood watch, the weather service issued a flood advisory for parts of Hawaii island until 7:30 p.m. Rain was falling at a rate of 2 to 3 inches per hour near Honokaa, and the advisory also covered Honomu, Kukuihaele, Papaikou, Waimanu valley, Waipio valley, Ookala, Laupahoehoe, Pepeekeo, Paauilo, Ninole and Hakalau.

The system is traveling toward the southwest from the northeast, he said. “It’s expected to linger over us tomorrow and then eventually move off to the west on Friday.”

On Tuesday night, the rain wreaked havoc on Maui, flooding highways, causing landslides and forcing some evacuations.

On Oahu, a house on Maunalaha Road in Makiki Heights sustained flood damage when a boulder and other debris clogged a culvert in a stream next to the house in the middle of the night, causing water to rush onto the property’s backyard, city officials said. Mud and debris also came down, city officials said.

The family received assistance from the American Red Cross.

Meanwhile, the Hawaii State Archives building was forced to shut down today after a leak to a section of the roof of the building caused rain to enter through a vent in the second-floor stacks area.

“The rain was limited to one small row of records, all of which were housed in archival quality cardboard boxes,” state Archivist Adam Jensen said, in a statement. The cardboard acted to “wick the water away from the records” contained within the boxes and, while some records were damp, they did not appear to sustain lasting damage, he said. The agency is expected to reopen to the public Thursday.

The city shut down West Loch Golf Course in Ewa this afternoon, and traffic was unusually heavy westbound on H-1 freeway earlier than standard afternoon rush-hour.

Meanwhile, Joint Base Pearl Harbor Hickam placed itself under a Thunderstorm Condition 2 from 1 to 10 p.m. today, urging military personnel to “take precautions for a state or readiness on short notice.”

Windward and mauka sections of Oahu are expected to experience occasional showers with a slight chance of thunderstorms this afternoon and through the evening. The Leeward area is anticipated to have scattered showers also with a slight chance of thunderstorms this afternoon and through the evening with a slight chance of thunderstorms and isolated showers after midnight.

Locally heavy rainfall is possible, NWS said.

4 responses to “Thunderstorms, heavy downpours could be in store for isles”

  1. saywhatyouthink says:

    All this hoopla with NWS alerts and warnings over what used to be just an ordinary rainy day.
    They need to justify the need for their jobs I guess, even though they’re wrong half the time. If they keep ringing alarm bells every time it rains a little, pretty soon no one will listen to their alerts when there really is a storm brewing. Guy Hagi seems to have learned his lesson after numerous false alarms, he hasn’t been sensationalizing the weather like he used to.
    Hard to keep that up when you’re always wrong.

  2. SCOOBYSNAKR808 says:

    Yesterday I sat there watching the forecast and said “betcha some dummy is saying that tomorrow will be a good day to go hiking” and then have to get themselves rescued. Watching today’s news sure enough there is another hiker that used no common sense and also looks like she went out alone. What a drain on our resources and also putting our first responders in jeopardy.

  3. wrightj says:

    We must take the warnings seriously; look what happened overnight.

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