Flash flood warnings issued for Oahu and Kauai

UPDATE: 6:25 a.m.

The flash flood warning for Oahu has been extended until 9:45 p.m.

”At 6:19 a.m., radar and automated rain gauges indicated heavy rain falling over the Koolau Mountains with the heaviest rain between Maunawili and Hauula,” the updated National Warning Service warning said. “Rain was falling at a rate of 2 to 3 inches per hour. Flash flooding is ongoing or expected to begin shortly. Additional bands of rain will likely continue to anchor along the Koolau Mountains through the morning.”

The warning areas include Honolulu, Waipio, Waiahole, Waikane, Kahaluu, Ahuimanu, Pearl City, Aiea, Halawa, Mililani, Kaaawa, Moanalua, Salt Lake, Waikele, Wahiawa, Punaluu, Waipahu, Kalihi, Kaneohe and Wheeler Field.

Kauai remains under a warning until 9 a.m.

6:05 a.m.

The National Weather Service in Honolulu extended the flash flood warning for Kauai until 9 a.m. today.

“At 5:32 a.m., radar indicated heavy rain over the island of Kauai,” the updated warning says. “Rain was falling at a rate of 2 to 4 inches per hour. Additionally, the Hanalei River water levels are currently high enough for Kauai Police to close Kuhio Highway near the Hanalei River Bridge due to significant water over the roadway. Flash flooding is ongoing.”

Oahu remains under a separate warning until 6:45 a.m.

Both islands and Niihau are also under a flood watch through this afternoon.

PREVIOUS COVERAGE

Oahu and Kauai are under flash flood warnings this morning as heavy rain falls over large parts of both islands.

The National Weather service issued the warnings until 6:45 a.m. for Oahu, and until 6 a.m. for Kauai.

“At 4:28 a.m., radar and automated rain gauges continued to show that heavy rain was falling along a convergence band anchored over the Koolau Mountains,” the Oahu warning said. “The heaviest rain was falling at a rate of 2 to 4 inches per hour under this band and stream levels continue to rise. Flash flooding is ongoing or expected to begin shortly.

The warning for Oahu covers Honolulu, Waipio, Waiahole, Waikane, Kahaluu, Ahuimanu, Pearl City, Aiea, Halawa, Mililani, Kaaawa, Moanalua, Salt Lake, Waikele, Wahiawa, Punaluu, Waipahu, Kalihi, Kaneohe and Wheeler Field.

For Kauai, the weather service warning covers the entire island.

“At 3:49 a.m., radar indicated heavy rain over windward sections of Kauai, with rain falling at a rate of 2 to 3 inches per hour in the heaviest showers,” the warning said. “Additionally, Emergency Management reported that the Princeville side of Kuhio Highway has been closed near the Hanalei River Bridge due to water over the roadway.”

NWS advises the public:

>> To stay away from streams, rivers, drainage ditches, and culverts, even if they are dry.

>> Do not cross fast flowing or rising water in your vehicle, or on foot. Turn around, don`t drown.

>> Be especially cautious at night when it is harder to recognize the dangers of flooding.

The heavy rains may cause rock and mudslides in steep terrain areas, forecasters said.

Both islands and Niihau are also under a flood watch through this afternoon.

“An upper-level trough swinging through the northwestern islands today will produce periods of heavy showers and isolated thunderstorms,” forecasters said. “The trough axis should lift north of the area later this afternoon, which should diminish the flooding threat.”