UPDATE: 10:30 a.m.
A flash flood warning has been issued for Oahu and is in effect through 1:30 p.m. today.
At 10:23 a.m., radar indicated heavy rain over the Koolau mountains between Kaneohe and Kahuku, according to the National Weather Service. Rain was falling at a rate of 2 to 3 inches per hour. Flash flooding is expected to begin shortly.
Locations in the warning include, but are not limited to, Ahuimanu, Waikane, Hauula, Laie, Waiahole, Kahaluu, Kahuku, Punaluu, Kaaawa, Wahiawa, Aiea and Halawa.
The National Weather Service issued a special weather statement for most of Oahu this morning.
At 10:12 a.m., a strong thunderstorm was located near Kahuku, or 25 miles north of Honolulu, moving east at 15 mph, weather officials said.
Wind gusts of 45 to 50 mph have been observed near Haleiwa and will be possible as this storm continues to track eastward at around 15 mph.
Locations impacted include Honolulu, Waimanalo, Haleiwa, Wahiawa, Hawaii Kai, Ahuimanu, Punaluu, Kahuku, Kalihi, Waiahole, Moanalua, Pearl City, Hauula, Kaneohe Marine Base, Laie, Palolo, Kahaluu, Salt Lake, Kailua and Manoa.
Torrential rainfall is also occurring with this storm and may cause localized flooding. Do not drive your vehicle through flooded roadways.
Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle.
Weather officials canceled the flood advisory for the island of Kauai after heavy rain moved offshore. However, the flash flood watch for Kauai County remains in effect through 6 p.m.
A flood advisory is in effect for the island of Kauai through 7:30 a.m.
Radar at 4:23 a.m. indicated heavy rain from slow-moving storms developing over Kauai, according to the National Weather Service. Rain was observed falling at 1 to 2 inches per hour and weather officials said to expect rapidly rising waters in local rivers and streams.
An earlier flash flood watch remains in effect for Kauai County through this afternoon.
A high surf advisory has been issued for the north- and west-facing shores of the isles stretching from Niihau to Maui, in effect from 4 p.m. today through 6 p.m. Saturday, weather officials said.
An incoming, northwest swell is expected to bring advisory-level surf to exposed north- and west-facing shores, the National Weather Service said. Surf is expected to reach 10 to 15 feet late this afternoon for isles from Niihau to Maui, rising to 18 to 24 feet by Friday morning.
Surf is expected to reach 6 to 10 feet along west-facing shores of Oahu and Molokai late this afternoon, and rise to 12 to 18 feet by Friday morning.
Expect strong, breaking waves, shore break, and strong rip currents, making swimming difficult and dangerous. Beachgoers, swimmers, and surfers should exercise caution and heed all advice given by Ocean Safety officials.
A cold front, meanwhile, is approaching from the northwest, forecasters said, and will keep winds light today. Increasing humidity ahead of the front is expected to bring afternoon clouds and showers, along with a chance of thunderstorms for some spots.
The front approaches Kauai late tonight, and stalls near Oahu on Friday, bringing a few showers and thundershowers. The breezy trades, however, are expected to return this weekend, the last one for the year 2018. Nice weather is expected for New Year’s Eve and beyond.