With a weakening front over the islands and an upper low northwest of Kauai, heavy showers and thunderstorms developed over the state.  Drenching rain led to periods of flash flooding over several isles, and gusty winds downed trees and power lines.  The cost of any damages was not available.
A man on the Big Island of Hawaii perished, apparently from being tossed violently by gusty winds associated with a thunderstorm in the later evening on the 18th of February.  No other fatalities or serious injuries were reported.

Heavy Rain in KAUAI, HAWAII
From 18-FEB-18 19:25:00 to 18-FEB-18 20:30:00 (HST-10)
Location: ANAHOLA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy Rain in HAWAII, HAWAII
From 19-FEB-18 14:49:00 to 19-FEB-18 16:06:00 (HST-10)
Location: OOKALA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flash Flood in HAWAII, HAWAII
From 18-FEB-18 20:16:00 to 19-FEB-18 00:49:00 (HST-10)
Location: HONOKAA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Flooding rain damaged a store in the Hamakua District on the Big Island of Hawaii, in the town of Honokaa.  Also, a man died in leeward Big Island in the later evening on the 18th.  His was staying in a shack-like structure on a coffee farm in Holualoa when, apparently, strong and gusty winds from a thunderstorm blew the structure about 150 feet from its foundation; and he was killed.

Thunderstorm Wind in HAWAII, HAWAII
From 18-FEB-18 17:48:00 to 18-FEB-18 17:48:00 (HST-10)
Location: HOLUALOA
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A shack-like structure was blown 150 feet off its foundation by the thunderstorm winds. Time of event estimated based on radar.

Heavy Rain in MAUI, HAWAII
From 15-FEB-18 03:54:00 to 15-FEB-18 12:02:00 (HST-10)
Location: HONOKAHUA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy Rain in HAWAII, HAWAII
From 15-FEB-18 10:38:00 to 16-FEB-18 02:18:00 (HST-10)
Location: HAWI
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy Rain in HAWAII, HAWAII
From 16-FEB-18 15:29:00 to 16-FEB-18 18:36:00 (HST-10)
Location: HILO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy Rain in MAUI, HAWAII
From 17-FEB-18 18:41:00 to 17-FEB-18 19:50:00 (HST-10)
Location: KOELE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flash Flood in HONOLULU, HAWAII
From 17-FEB-18 22:20:00 to 18-FEB-18 04:52:00 (HST-10)
Location: WAIKANE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

In windward Oahu, Kamehameha Highway near Waikane Stream, between Waikane Valley Road and Kualoa Ranch, was closed due to flooding.

Heavy Rain in MAUI, HAWAII
From 18-FEB-18 11:47:00 to 18-FEB-18 14:35:00 (HST-10)
Location: MOLOKAI AIRPORT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flash Flood in HONOLULU, HAWAII
From 18-FEB-18 13:10:00 to 18-FEB-18 20:04:00 (HST-10)
Location: WAIKANE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

In windward Oahu, heavy rain again closed Kamehameha Highway in the area along the Waikane and Waiahole streams.  Also, firefighters responded to a man trapped in his vehicle by rising water near Kamehameha Highway and Wailehua Road.  Another area of flooding occurred near the junction of Kalanianaole Highway and Kealahou Street near Sandy Beach in southeast Oahu around 1845 HST on the 18th.

Heavy Rain in MAUI, HAWAII
From 18-FEB-18 13:04:00 to 18-FEB-18 15:38:00 (HST-10)
Location: KOELE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Flash Flood in MAUI, HAWAII
From 18-FEB-18 14:17:00 to 18-FEB-18 18:17:00 (HST-10)
Location: WAIHEE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

In West Maui, flooding waters covered portions of Kahekili Highway at the Waihee Valley Bridge. Also, portions of Iao Valley Road and Waiehu Beach Road were closed due to high water. The Fire Department, as well, reported that a young man had to be rescued from rising water at a home at 140 River Road.

Heavy Rain in KAUAI, HAWAII
From 18-FEB-18 15:01:00 to 18-FEB-18 17:38:00 (HST-10)
Location: KAPALUA HEIAU
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy Rain in MAUI, HAWAII
From 18-FEB-18 18:22:00 to 18-FEB-18 23:03:00 (HST-10)
Location: NAPILI
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy Rain in MAUI, HAWAII
From 18-FEB-18 18:30:00 to 18-FEB-18 20:57:00 (HST-10)
Location: MAUNALOA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy Rain in HAWAII, HAWAII
From 17-FEB-18 18:58:00 to 17-FEB-18 20:08:00 (HST-10)
Location: WAIKOLOA VILLAGE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Heavy Rain in HAWAII, HAWAII
From 18-FEB-18 12:26:00 to 18-FEB-18 16:25:00 (HST-10)
Location: HAWI
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations