UPDATE: 9am

National Weather Service forecasters said heavy rain over windward Oahu at a rate of up to 3 inches per hour “could quickly lead to runoff and flash flooding.”

In an update to the flash flood warning for Oahu, which is in effect until 9 a.m., forecasters said: “Creek levels are expected to continue to rise. Water could flood some roads, including Kamehameha Highway. Additionally, Manoa Stream at Woodlawn has reached a height of 10.5 feet, which is known to cause impacts that will also result in flooding of nearby properties. Flash flooding is likely to continue.”

A flash flood warning also remains in effect on Maui until 9:45 a.m., but forecasters said the rain there is easing. Still, “water levels remain dangerously high in most streams on eastern Maui,” they said.

8 a.m

The National Weather Service has issued a flood warning for the main Hawaiian Islands through Sunday afternoon.

“Flood-prone roads and other low-lying areas may be closed due to increased runoff and overflowing streams. Major flooding and property damage may occur in urban areas

A weather system moving across the islands through Sunday will result in “a very unstable atmosphere.” “Conditions are becoming increasingly favorable for the development of heavy showers and thunderstorms, particularly over windward areas,” the flood watch statement said.

The flood warning is in addition to the flash flood warnings in effect for Oahu and Maui. (See below.)

And a high surf warning is in effect for all east coasts.

Hawaii Island Civil Defense said the Bayfront Highway in Hilo remains closed in both directions today due to high surf and debris on the roadway.

7:05 am

Flash flood warnings were issued for Oahu and Maui this morning.

The National Weather Service in Honolulu said the warning lasts until 9:30 a.m. for Oahu and 9:45 a.m. for Maui.

“At 6:40 a.m. radar indicated heavy rain over windward of Oahu. Rain rates of 1.5 to 2.5 inches per hour were observed,” forecasters said. “Intermittent heavy rainfall over already saturated ground can quickly lead to runoff and flash flooding. Water levels in the streams are expected to continue to rise. Flash flooding is ongoing or expected to begin shortly.”

The Oahu warning applies to Honolulu, Ahuimanu, Kaneohe, Kahaluu, Waiahole, Kalihi, Maunawili, Moanalua, Aiea, Halawa, Waikane, Kaneohe Marine Base, Manoa, Kailua, Salt Lake, Pearl City, Palolo, Waimanalo, Kaaawa and Mililani.

In Maui, meteorologists said: “Radar indicated heavy rain over windward east Maui. Rain fell at a rate of 2 to 3 inches per hour. Flash flooding is ongoing or expected to begin shortly.”

The Maui Warning applies to Nahiku, Keanae, Kipahulu, Hana, Kaupo, Huelo, Makawao, Haiku-Pauwela, Pauwela, Paia, Wailua, Haleakala National Park, Kailua and Hamoa.

The warnings replace flood warnings issued today and could be extended if flooding continues, the weather service said.

PREVIOUS COVERAGE

According to the National Weather Service in Honolulu, parts of Oahu and Maui are under a flood warning this morning as a rainy weather system begins to spread across the state.

The Oahu advisory, which lasts until 7 a.m., covers Kaneohe, Ahuimanu, Kalihi, Maunawili, Manoa, Moanalua, Kahaluu, Halawa, Kailua, Aiea, Palolo, Waiahole, Waimanalo, Waikane, Pearl City, Hawaii Kai, Heeia, Nuuanu and Fort from Shafter and Makiki-Tantalus.

“At 3:54 a.m. radar indicated heavy rain over the Koolaus. “Rain was falling at a rate of up to 5 cm per hour,” the warning said.

Forecasters said the Hawaiian Islands will experience periods of moderate to locally heavy rain today and tomorrow, spreading northwest across the state, with isolated thunderstorms possible over the eastern end of the state.

Light to moderate trade winds are expected through this evening, followed by “breezy winds with slightly drier conditions” next week, it said today.

For Maui, the warning is in effect until 8:15 a.m. and applies to Nahiku, Keanae, Kipahulu, Hana, Kaupo, Huelo, Makawao, Haiku-Pauwela, Pauwela, Paia, Wailua, Haleakala National Park, Kailua, Hamoa and Hookipa Beach Park.

“At 5:11 a.m. radar indicated heavy rain over the east and southeast slopes of Haleakala. “Rain fell at a rate of up to 2 inches per hour,” the Maui advisory said.

In addition to the flood warnings, a high surf warning is in effect for all east coasts until 6pm today. The weather service forecasts large breaking waves of up to 8 to 12 feet this morning, falling to 7 to 10 feet in the afternoon.

Meanwhile, Hurricane Kristy is “rapidly weakening” in the eastern Pacific and is expected to weaken into a post-tropical remnant low by Sunday before reaching the central Pacific, according to the National Hurricane Center in Miami.

Kristy, a major hurricane earlier this week far from land in the eastern Pacific, had maximum sustained winds of about 75 mph (120 km/h) with stronger gusts as of this morning, forecasters said.