UPDATE: 6:19 a.m.

The flash flood warning for Oahu and Kauai has been canceled.

12:40 a.m.

A flash flood warning has been issued for Oahu and Kauai.

On Oahu, the warning is in effect until 2:45 a.m., as heavy rains stretch from Punaluu to between Pupukea and Kahuku.

The National Weather Service reported rain falling at a rate of between 1 and 3 inches per hour, and up to 5 inches in that area, leading to potential landslides.

On Kauai, the warning is in effect until 3:30 a.m., with heavy rain falling from Kalalau Valley to Hanalei to Moloaa to near Wailua, at a rate of between 2 and 4 inches per hour.

The flash flood warning for both islands may be extended if heavy rain persists.

8:45 p.m.

Tonight’s flood advisory for Oahu has been extended until 12:45 a.m. Saturday.

Radar this evening indicated rain falling at a rate of 2 to 3 inches per hour in the area of Hauula and Punaluu. The rain was moving toward Sunset and Pupukea as of 8:32 tonight, the National Weather Service said. Areas in the path of this cell can expect heavy downpours leading to locally heavy ponding of roadways. Area streams can also expect a rapid rise.

7:20 p.m.

A flood advisory is in effect for Oahu until 9:45 tonight.

Radar indicated heavy rain falling over Windward Oahu and the Koolau mountains this evening. Rain was falling at a rate of 1 to 2 inches per hour and area streams are on the rise, according to the National Weather Service. Minor flooding of low lying and poor drainage areas can be expected.

Locations in the advisory include but are not limited to Honolulu, Waimanalo, Wahiawa, Hawaii Kai, Ahuimanu, Punaluu, Kahuku, Kalihi, Waiahole, Moanalua, Pearl City and Hauula.

4 p.m.

A flash flood watch is in effect for Oahu, Kauai and Niihau through late Saturday night.

An upper low will approach from the northwest tonight bringing unstable atmospheric conditions across the western end of the state, the National Weather Service said. Heavy rain and thunderstorms will be possible through Saturday night. East southeast winds will focus rainfall over windward slopes as well as urban areas along the south shores.

A high surf advisory has been issued for east shores from Kauai to Hawaii island until 6 a.m. Saturday.

The National Weather Service says strong trades will maintain elevated, rough surf of 8 to 12 feet along east shores this morning before lowering to 6 to 10 feet tonight.

Surf elsewhere will remain low — 2 to 4 feet along south shores through Saturday, and 1 to 3 feet along north and west shores through Sunday.

Officials warn of strong, breaking waves and rip currents in advisory areas, making swimming difficult and dangerous. Beachgoers should heed all advice by ocean safety officials.

A high-pressure system north of the Hawaiian isles will keep moderate trades in place today, forecasters said.

The winds will decrease in the next few days, but two low-pressure systems west and north of Kauai are expected to bring periods of heavy showers and isolated thunderstorms this weekend.

Today’s highs ranging from 77 to 82 degrees Fahrenheit, with winds of 15 to 25 mph. Tonight will be cloudy, with occasional showers and lows from 65 to 70. Trades tonight slow down to 10 to 20 mph.

A small craft advisory also remains in effect for all Hawaiian waters northwest of Kauai to the southeast of Hawaii island through 6 a.m. Saturday.