Hawaii Braces for Days of Heavy Rain and Flash Flooding This Week

Tropical Depression Olana will not make a direct landfall on Hawaii, but it will come close enough to send heavy rain and other impacts to the island chain. Here is a look at the latest tropical weather maker to impact the islands over the last few months as a strong El Niño continues to drive the parade of storms.

Hawaii Braces for Latest Tropical Weather Event

The supercharged Pacific hurricane season is showing no signs of slowing down. Olana is the latest feature to form in the Central Pacific. The most recent forecast models from the National Hurricane Center (NHC) show Olana will make a sharp curve back to the west, sparing Hawaii from a direct landfall. However, increasing moisture east of the storm will result in a steady stream of precipitation and the threat of flash flooding for much of the island chain.

Forecasters had been monitoring this batch of rain showers and thunderstorms since last week. The feature was upgraded to a tropical storm status over the weekend before being downgraded to a mere depression on Monday morning. The system will continue to weaken on Tuesday as it loses its wind intensity.

Despite the weakening trajectory of this feature, the moisture associated with it will be enough to significantly disrupt outdoor plans and travel across Hawaii. Several inches of rain are on tap over a period of three days beginning on Tuesday and lasting through Thursday for much of the Aloha State. The forecast is calling for widespread rain of 2 to 8 inches across Oahu, Molokai, and Maui. Locally higher amounts are possible for the higher terrain.

Honolulu, the largest city in the state, will be in the bullseye of the most potent rain bands and resulting flash flooding. While several other areas of the islands have been slammed by tropical weather this season, Honolulu has managed to avoid the worst impacts thus far.

Although most tropical weather systems approach Hawaii from the east, Olana is coming at the islands from the west. The unique flow of moisture from south to north could result in persistent rain for parts of the islands that are typically protected by the rain shadow.