HONOLULU (KHON2) – A lot of people will be paying special attention to the forecast for the next few days as many will be heading outside for graduation ceremonies, festivals, and Mother’s Day celebrations.
Weather officials said severe weather is coming and can happen quickly, the models are uncertain about when and where will see the most impacts.
The National Weather Service said this storm is unusually strong for this time of year.
“We have a fairly strong system that’s setting up and it’s unusual for May, usually we’re entering the dry season now,” explained NWS Honolulu meteorologist Derek Wroe. “So we have a particularly strong upper level disturbance that’s going to drop down, but the most important thing to keep in mind is that this is going to have the ability to create heavy showers and thunderstorms.”
He said flash flooding is likely, as the showers can be spotty and isolated.
“It could be sunny for a few hours, and then you could have heavy shower development over a relatively quick period of time,” he added.
People should avoid hiking in areas with stream beds in the coming days because rain could be falling up in the mountains, and flash flooding can occur even if it’s sunny in your area.
“And it doesn’t have to be raining where you are or for a thunderstorm to be on top of you, for you to be struck by lightning,” Wroe added.
He said this weather event is capable of producing hail.
“We don’t get a lot of situations where hail will make it down at the surface around here in Hawaii, but this does have the potential to see hail possibly up to an inch in size so that could do some damage,” Wroe added. “We’re still assessing that threat and can’t really pinpoint where it is right now.”
Experts said this type of storm system is more typical in the winter time, but the chance of severe weather is much greater because of it occurring in May.
“We get a little bit more daytime heating because the sun’s out earlier and it’s out longer, it’s a little bit more intense and that adds to the instability as well heats up that land and creates a little bit more instability,” Wroe said.
He said the thunderstorms can develop quickly too; going from no wind and sunny conditions to huge wind gusts and heavy downpours.
“It’ll be capable of producing strong wind gusts just before and right after that heavy shower,” Wroe said. “You can see wind gusts in excess of 50 miles per hour with a shower which is concerning since we know we have a lot of graduation activities going on.”
Honolulu and Leeward Community Colleges said outdoor graduation ceremonies will be rain or shine on Friday and umbrellas are allowed.
Leeward CC will have a tent for coverage.
The organizers for the Palm Tree Festival at Turtle Bay said they are monitoring weather conditions and will alert attendees via social media should there be any changes.
The weather service said models aren’t in agreement about who will see the most impacts but it’s likely anywhere from Oahu to Hawaii island.
“With these large events, there is the likelihood we will have significant impacts with driving safely on our roads,” said Hawaii Dept. of Transportation Director Ed Sniffen. “Go slowly, you might be late to some of these events, but you’re going to get there.”
Sniffen said contractors pulled all equipment from Wailua Stream Bridge on Kauai, they’ve also cleared debris from streams on Oahu and have crews posted along the Hamakua Coast should debris come down onto the roads.
“I think the main thing is, if there’s a severe thunderstorm watch or warning issued, seek shelter immediately to get inside,” said Hiro Toiya, Honolulu Dept. of Emergency Management director.
Power outages are also possible so people should plan ahead.