The National Weather Service has issued a Flash Flood Watch for the County of Maui through late Thursday night.
A Flash Flood Watch means that conditions may develop that lead to flash flooding.
According to the National Weather Service, moisture from Tropical Storm Olivia is expected to move over the state starting Tuesday evening. Intense rainfall will be possible, especially along the east-facing slopes.
Olivia is forecast to produce total rainfall amounts of 10 to 15 inches. Isolated maximum amounts of 20 inches may occur along the windward sections of Maui County.
Rain events of this size can cause widespread flooding and can affect areas that do not usually flood. Low spots in roads will become dangerous and impassable due to severe runoff. Debris in streams and gulches may clog bridges and culverts resulting in dangerous flooding. Numerous landslides are expected, especially along the Hana Highway.
In addition, NWS has issued a High Surf Warning for Maui and Molokai through 6 p.m. on Wednesday.
A High Surf Warning means that dangerous, battering waves will pound the shoreline. This will result in very dangerous swimming conditions, and deadly rip currents.
A swell from Tropical Storm Olivia will gradually rise through Tuesday, then rapidly rise Tuesday night as Olivia nears the Hawaiian Islands.
Expect surf of 5 to 8 feet tonight along east facing shores, building to 10 to 14 feet Tuesday, then rising to 12 to 20 ft Tuesday night.
Forecast surf heights are estimates of the height of the face or front of waves.