A weather system moving across the state Tuesday brought “some pretty impressive rainfall totals” to the Big Island, especially in East Hawaii.
“A lot of places have been getting 2 to 3 inches of rain in the last 12 hours, but it’s been falling at a fairly steady rate,” said National Weather Service forecaster Derek Wroe late Tuesday afternoon.
In an abundance of caution, the weather service extended a flash flood watch until 6 a.m. today.
In the 24-hour period ending at 4 p.m. Tuesday, the Waiakea Experimental Station in Hilo received 5.94 inches of rain. Other rainfall totals in East Hawaii for that time period include: Piihonua, 5.74 inches; Glenwood, 5.48 inches; Pahoa, 4.81 inches; and Hilo International Airport, 4.57 inches.
“We’ve had some reports from Civil Defense officials that there’s been some ponding in the roadways around Hilo, but other than that, we haven’t seen any problems,” Wroe said. “The streams we have sights on on the Big Island haven’t been showing anything significant. Most of the rain has been sort of slow and steady.”
Tuesday’s rainfall apparently did cause some snarled traffic, however.
State Rep. Joy San Buenaventura of Puna took to Facebook on Tuesday morning to post about bumper-to-bumper traffic on Highway 130 between Hawaiian Paradise Park and Keaau.
“Never saw it this bad before. 1/2 hour just to get out of HPP,” San Buenaventura wrote. Despite her concerns about making a flight to Honolulu, she managed to board on time, because of Transportation Security Administration pre-check.
“Be careful out there. It’s wet; rainy and lots of traffic,” she warned.
All main roads, including Hilo Bayfront Highway, were open as of 5:30 p.m. Tuesday.
The drier leeward side of the island also received significant rainfall, with Kealakomo getting 4.52 inches in the 24-hour period ending 4 p.m. Tuesday. Reports from other leeward gauges include: Kapapala Ranch, 2.44 inches; Pahala, 2.03 inches; Kahuku Ranch, 1.8 inches; Honaunau, 1.42 inches; and Kealakekua, 1.18 inches.
A severe thunderstorm just offshore from the Puna coastline caused forecasters to post a special marine warning at about 2:30 p.m. Tuesday, warning mariners about lightning and possible waterspouts. That warning has since expired.
“It was just past Pohoiki, and it went out just past Kapoho to the tip of Cape Kumukahi and then went just offshore and weakened,” Wroe said. “It never went onshore, but it had a significant radar signature when it was over the water just a few miles out. We have not had any confirmation that there was a waterspout in there, but it was certainly capable of producing a strong waterspout.”
Wroe said that while the rain will diminish starting today, “You’ll see some continued showers for the next, at least, several days, but not steady and persistent like we have seen over the last 24 hours.”
A winter storm warning for Big Island summits also was extended until 6 a.m. today. Winds of more than 50 mph were predicted for the summits of Maunakea and Mauna Loa, and Wroe said the summits were receiving what he called a “slushy rain/snow mix.”
The Maunakea Access Road was closed to the summit late Tuesday afternoon. At 5:30 p.m., the summit temperature was 34 degrees with winds from the south at 30 mph.
Email John Burnett at jburnett@hawaiitribune-herald.com.