Flossie made a brief, but eventful, pass through the Central North Pacific Ocean. Tropical Storm Flossie entered the Central Pacific Hurricane Center’s area of responsibility in the early morning hours of July 27.
It became the first storm to trigger tropical cyclone related warnings for the state of Hawaii since a previous incarnation of Flossie in 2007. Initial data suggest that the center of Flossie never made landfall, but came close on Kaua’i in the early morning hours of July 30.
Tropical Storm Flossie encountered strong northerly wind shear as it approached the island of Hawaii. This shear led to a decoupling of the storm circulation, with the deep convection moving southward while the low level center tracked to the west-northwest. The southeastern quadrant of Flossie sparked heavy rainfall, gusty winds, and intense thunderstorms over Hawaii and Maui Counties during the afternoon and evening of July 29.
Significant precipitation fell across much of the state, although flooding was generally minor. Here are the average and peak rainfall amounts across the state by county:
Hawaii County -0.25 to 0.75 inches, peak 2.86 inches
Maui County -1 to 2 inches, peak 5.27 inches
Honolulu County -0.25 to 0.75 inches, peak 2.71 inches
Kaua’i County – 0.25 to 0.75 inches, peak 3.31 inches
The strongest winds associated with Flossie’s closest approach to Hawaii were found in the southeastern quadrant of the storm and within the thunderstorms that developed on the afternoon and evening of July 29.
Here is a list of the strongest sustained winds, recorded by county, as Flossie impacted the state.
Hawaii County – 31 mph in Kona
Maui County – 33 mph in Kahului
Honolulu County – 27 mph in the Waianae Mountains
Kaua’i County – 26 mph in Kekaha
Gusty winds and lightning accounted for the majority of damage associated with Flossie. Most damage consisted of down trees, with the majority occurring in Hawaii and Maui Counties during the afternoon and evening of July 29. Several reports of boulders falling on roads were received from Oahu and Maui. Frequent cloud to ground lightning strikes across Maui and Moloka’i led to numerous power outages, damage to at least one home, and one injury when an individual was shocked inside his home. At various times during the event more than 10,000 homes were without power due to falling trees and/or lightning strikes.
High surf of 6 to 15+ feet impacted most islands with minor coastal inundation reported.
The track, rainfall, wind, and damage information shared in this document should be considered preliminary. Total damage estimates are not yet available.