Having been put through the wringer last week with daily multiple flash-flood warnings, watches and advisories, the islands are still sopping wet and the flooding may not be over yet.
The National Weather Service said heavy rains from a weakening cold front remain a threat before a slow drying trend begins and the tradewinds return Tuesday, gradually increasing through the end of the week. A flash-flood watch was in effect for all islands until 6 a.m. today.
“We’re looking for a drying trend by the middle of the week,” National Weather Service lead forecaster Tom Birchard said cautiously on Saturday, adding, “Grain of salt with that, for sure.”
Despite the forecast for improving conditions, the weakening weather system will keep things unstable, with the potential for more rain, he said.
“Kauai and Oahu could be coming under the gun again,” Birchard said, since the ground is already saturated and “most of the rain is turning into runoff. It takes less rainfall than normal to cause flooding
impacts.”
He called weather conditions up and down the island chain over the past week “one of the more impactful rainfall events in a couple of years … It’s one of the longer-lived events as far as statewide impacts, with serious events on Maui, Oahu and Kauai.”
The weather pattern began March 6, prompting an initial flash-flood watch issued for Kauai. On March 7, the National Weather Service, with moisture expected from the southeast, issued a flash-flood watch for Hawaii island.
A watch for the rest of the islands came on Monday. That’s when Maui was pounded by heavy rains. Peahi Bridge and other
sections of roadway in Haiku were washed out
and 150 homes were evacuated as Kaupakalua Reservoir swelled and topped its earthen dam.
On Tuesday, Haleiwa on Oahu’s North Shore experienced large-scale flooding
after more than 16 inches of rain were measured in the Koolaus. The Weather Service sounded a warning a few hours ahead of the impending flash-flooding of Opaeula Stream and the town was evacuated.
Then on Thursday, a massive landslide in Hanalei on Kauai’s Kuhio Highway cut off vehicular access to the island’s north shore, trapping residents and visitors. It will likely take at least three months to clear and safely restore the highway for public use, according to the state Department of Transportation.
In the six-day period ending at noon Saturday, Kauai’s Mount Waialeale topped the state’s rainfall totals at
37.52 inches; followed by Oahu’s Poamoho Rain Gauge No. 1, which led to the Haleiwa flooding, with 26.5 inches; Punaluu Stream on Oahu with 24.63 inches; and North Wailua Ditch on Kauai with 24.4 inches.
Other areas that got a drenching included Kilohana on Kauai, with
22.88 inches of rain over that period; West Wailuaiki on Maui with 21.38 inches; and Pahoa on Hawaii island with 19.95 inches.
On Saturday, Maui was the only place to see significant flooding. Heavy showers locked over the south-
east slopes of Haleakala overnight Friday into Saturday for eight to 10 hours, Birchard said. Although most of the areas experiencing flooding were sparsely populated, the road in remote Kaupo was damaged.
Haleakala National Park’s Kipahulu District was temporarily closed Saturday due to severe weather and road closures; however, the Summit District remained open.
On Hawaii island, police closed Highway 11 in Kau at the 60-mile marker for a few hours Saturday near Honuapo due to flooding. Police said there are no alternate routes.
Kauai’s Hanalei River was rising Saturday, prompting a warning with no significant impacts, officials said.
