The biggest threat the Big Island faces from Tropical Storm Niala is flash flooding, according to authorities. ADVERTISING The biggest threat the Big Island faces from Tropical Storm Niala is flash flooding, according to authorities. As of 5 p.m. Friday,
The biggest threat the Big Island faces from Tropical Storm Niala is flash flooding, according to authorities.
As of 5 p.m. Friday, the storm was about 375 miles southeast of Hilo packing maximum sustained winds of 50 mph with locally higher gusts. The storm was moving northwest at 7 mph.
“Right now, the track takes it over a hundred miles south of the Big Island,” NWS forecaster Derek Wroe said at about 5 p.m. Friday. “But due to the uncertainty of track forecasting, even though the threat passes, you can still get some effects. And we’re forecasting it to be weakening from later (Saturday) onward. The threat from flash flooding what we’re really trying to hammer home, because there’s a threat of a flash flood no matter how weak or strong the system is.”
An open-ended tropical storm watch is in effect for the Big Island and a flash flood watch remains in effect until Monday.
“The Big Island will be seeing the southeast swell building up off Niala (on Saturday),” Wroe said. “In places such as the Puna and Ka‘u coasts, the southeast facing shores, you can see waves up to about 12 feet when it starts to peak out later Saturday.”
Hawaii County Civil Defense Administrator Darryl Oliveira said late Friday afternoon that local authorities are gearing up for the possibility of floods.
“We could see the surf picking up on the southeast-facing shoreline, so we’re reviewing things with the Kapoho community, getting reports from our ocean safety people throughout the next couple of days to see if things change, especially during peak high tides, and, obviously, monitoring what flooding conditions could occur because of the rain,” he said.
“We’re not expecting a lot of wind with this event, although it’s possible tropical storm force winds could affect the Big Island. We’re showing sustained winds in the 50-mile-per-hour range with some higher gusts. But the storm is expected to stay far enough south we may not see significant winds. We’re definitely preparing for heavy rain showers and possibly some surf.”
About 10,000 or so revelers are expected to crowd the streets of downtown Hilo Saturday night for the KWXX Hoolaulea, and both the authorities and the event’s organizers are keeping a close watch on the weather.
“We’ve made sure the weather service is aware of that event, especially the concerns about any sort of electrical storm, in addition to the rain and the flooding,” Oliveira said. “They’ve got a lot of stages and scaffolding down there. So we’re definitely concerned, and we’ve been working with Chris Leonard, the event organizer, as well as with the weather service. … We’re definitely asking the weather service if they see any sort of electrical storm activity near the coast, to let us know.”
Leonard, the radio station’s owner, said the event is a go, but he’s monitoring weather forecasts and keeping in touch with authorities.
“At this point, we know there’s a chance we’re going to get a little bit of rain. And it wouldn’t be the first time it’s rained on us,” he said. “In years past, we’ve had significant amounts of rain. We’re fairly well prepared for that and I think the Hilo crowd is fairly well prepared for that.”
“We’re also keeping a very close eye on the potential for any wind. We’ve brought in additional counterweights for all of our staging. And we’ll keep a close eye for thunderstorms. We don’t know how that will play out and … we’ll be watching each successive update and continue to talk to Hawaii County Civil Defense and the National Weather Service.”
Wroe said when a tropical cyclone passes as closely as Niala is forecast “there’s always a risk” of a thunderstorm.
“If you can hear the thunder, then you’re definitely at risk for a lightning strike,” he said. “But that would be an isolated occurrence, the risk for thunderstorms. There are going to be some heavy showers and possibly thunderstorms developing over the Big Island as you get later into the day on Saturday and Saturday night. But the main threat were looking at with the system we’re looking at right now would be the threat for flash flooding.”
Oliveira advised residents to monitor media accounts and to be prepared, especially for flooding.
“In flood-prone areas, anytime there’s a break between these systems, they should do what they can to correct anything that’s correctable,” he said. “Simple things like clearing drainages on their property, checking the downspouts and seeing where the water’s running off to. If they are vulnerable to flooding, if there’s an opportunity to either acquire sandbags or do some basic preventive actions, that would be good.
“For boat owners, if they’re moored in the coastal areas on the east side, they should make sure their moorings are secure, because once the surf starts pick up or if there’s any kind of surge, that’s a problem.”
“Residents in the coastal areas should anticipate the possible high surf and surge issues and take whatever actions they feel are necessary, including leaving the area, if they need to.”
Email John Burnett at jburnett@hawaiitribune-herald.com.
