Forecasters report Maui County saw near to above-average rainfall through April

Rain gauges in Maui County recorded near to above-average rainfall so far this year through the end of April, according to a report from the National Weather Service.

Rainfall data showed a wide range of conditions during the month of April, the report says. Lānaʻi, central and east Molokaʻi, most of West Maui, and the windward slopes of Haleakalā had mostly near to above average monthly rainfall totals. The Upcountry and lower leeward slopes of Haleakalā had below average April totals.

At the top of Puʻu Kukui in the West Maui Mountains, a gauge reported the highest monthly total of 35.87 inches (93% of average), and the highest daily total of 3.81 inches on April 8. The Puʻu Kukui rain gauge had the highest year-to-date total of 98.23 inches (73% of average).

Statewide, the National Weather Service said there was an above average number of trade wind days in April.

“The trades were most intense during the first week of the month, reaching gale force in the Alenuihāhā and Pailolo Channels, and over the waters just south of the Big Island,” the report says. The strong winds were attributed to an unusually strong high-pressure system far north of the island chain that peaked on April 3.

There was a break in trade winds from April 10-16 because of the development of a kona low northwest of the main Hawaiian islands.

Kauaʻi saw strong thunderstorms on the evening of April 11 with the rainy weather moving over the island from the southwest. The 15-minute data from rain gauges along the southern and southeastern sides of the island showed rainfall exceeding 4 to 5 inches per hour. Periods of intense rainfall continued through the night and into the morning of April 12. By the end of the event, several gauges recorded an impressive 10 to nearly 13 inches of rain in 12 hours.

The heavy rains caused flash flooding with significant damage within drainage basins from Wailua to Kōloa. Numerous homes received varying levels of damage, and several residents were evacuated, the weather service said. Many roads were also closed due to flooding and landslides.

The Hanalei River overflowed its banks and inundated Kūhiō Highway for several hours. No injuries were reported.

Another round of heavy rain, although less intense, occurred over Kauaʻi on April 14. That weather system moved over Oʻahu, with some minor flooding on the west side of the island.