Heavy rain and gusty wind across the state Sun- day produced flooding, caused power outages, prompted the closure of some attractions and contributed to strong turbulence that required 36 people aboard a Hawaiian Airlines flight from Phoenix to Honolulu to receive medical treatment.

A total of 20, including passengers and crew, were taken to three Honolulu-area hospitals. Eleven of them were in serious condition, and nine had minor injuries.

A flood watch was in effect until 6 a.m. today for the state, according to the Honolulu National Weather Service.

Numerous showers and thunderstorms will continue through today, with severe storms being capable of producing strong wind and hail, NWS said.

Strong and damaging southwest, or Kona, wind also will continue through today. Periods of heavy rain during this period could result in areas of flash flooding. Weather will gradually improve Tuesday with fair weather and much lighter wind expected by Wednesday.

The Honolulu Zoo was closed Sunday due to the storm.

The city closed its lights displays inside Honolulu Hale and Kapolei Hale at 4 p.m. in anticipation of severe weather including a high-wind advisory, the Mayor’s Office of Culture and the Arts and Department of Parks and Recreation said.

The East-West Center also announced that Sunday’s planned script reading of “Tamoree,” written by Kaonohiokalaealohilohinei “Kala” Muller, was canceled and that it hoped to reschedule the event for a later date.

A flood advisory was in effect for Hawaii island until 7:45 p.m. Sunday as a result of excessive rainfall. At 4:46 p.m. the radar indicated heavy rain falling at a rate of 1 to 2 inches per hour over portions of north and south Kona, and north and south Kohala and Hamakua districts.

“Residents along Western and Northern coastlines are encouraged to prepare for sustained winds of 20-40 mph, with gusts up to 60 mph. Heavy rain and thunderstorms are anticipated for the whole island,” Hawaii County Mayor Mitch Roth’s office said. “The Flash Flood and High Wind Warning issued by the National Weather Service is in effect through Monday evening.”

Waipio Valley Access Road was closed as of 3 p.m. Sunday until further notice.

A winter storm warning was in effect through 6 a.m. Tuesday for the Big Island summits.

The warning means significant amounts of snow, sleet and ice are expected or occurring with the possibility for strong winds that make travel very hazardous or impossible, officials said. “Any travel plans to the summit should be postponed until the threat diminishes,” officials said.

On Kauai, Ocean Bureau Safety personnel temporarily shut down the lifeguard towers at Poipu Beach Park, Salt Pond Beach Park and Kekaha Beach Park due to the inclement weather.

On Maui the summit of Haleakala National Park and the Pipiwai Trail in the Kipahulu District was temporarily closed due to severe weather at 4 p.m. Sunday, and all sunrise reservations for today were canceled.

A flash flood warning was in effect until 4:30 p.m. Sunday for Maui.

At 2:32 p.m. the radar showed heavy showers falling at a rate of 1.5 to 2.5 inches per hour across several areas of the island. The heaviest rain was slowly trending eastward and centered mostly around Kula and east to Hana and Hamoa.

“Flooding in drainages, streams, rivers, roads, properties, and other low-lying areas. Public road closures possible in some areas. Landslides are possible in steep terrain,” an advisory said.

A flood advisory was in effect until 4 p.m. Sunday for Lanai and until 4:15 p.m. for Molokai due to excessive rainfall.

A high-surf warning was in effect for the north- and west-facing shores of Oahu, Kauai, Molokai and Niihau along with the north-facing shores of Maui through 6 p.m. Tuesday.

Expect “dangerously large” breaking waves of 25 to 40 feet with ocean water surging and sweeping across beaches, potentially affecting infrastructure and roadways, forecasters said.