Photo: JILL K. BRIGGS / AFP / Getty Images
Tropical Storm Olana is forecast to bring heavy rain, flash floods, and possible mudslides across Hawaii from Tuesday through Thursday night, according to weather forecasters. While the storm will not make landfall and is expected to weaken into a remnant low west of the islands, its moisture will still affect all of Hawaii’s main islands.
A Flood Watch will go into effect Tuesday morning and remain through late Wednesday night. Forecasters estimate rainfall totals between two and eight inches, with the highest amounts possible in the mountains and higher elevations. The National Weather Service warns that these heavy downpours could lead to flash flooding and thunderstorms.
The deep tropical moisture from Olana is expected to disrupt outdoor plans, beach activities, and boat tours. As stated by AccuWeather’s lead hurricane expert Alexander DaSilva, “During El Niño, changes in atmospheric conditions can influence tropical activity and storm tracks across the Pacific. What makes this developing system particularly concerning is the potential for it to approach Hawaii from the west, which is a unique direction for tropical systems threatening the islands.”
Tropical Storm Olana is the sixth named storm to track near Hawaii in 2026, following Fausto, Lala, Lowell, Moke, and Nolo. Late-season tropical systems approaching Hawaii are rare, with only two other storms passing within 100 miles of the main islands in October.
The forecast also notes increased surf along north and west-facing shores on Tuesday and Wednesday, which may reach advisory levels, while east-facing shores will see smaller waves. Trade winds are expected to return by the weekend, but wetter-than-normal conditions could persist.
Meteorologists say the damp pattern could continue into early November, with the possibility of another Kona storm developing west of the islands over Halloween weekend, bringing more rain.