Flooding, Possible Thunderstorms, Predicted Through Saturday

The National Weather Service has issued a flash flood watch for the entire state through Saturday night and into Sunday morning.

A strong low-pressure system in the upper atmosphere moving south over the island chain is expected to destabilize the atmosphere beginning later today. Forecasters said in some areas that will mean heavy rain and the possibility of thunderstorms through at least 6 a.m. Sunday.

The heavy showers are expected to be slow-moving, which means accumulations of rainfall could be high.

“While heavy rain is not expected to be widespread, localized intense rainfall is likely to occur, potentially leading to flash-flooding in streams and urban areas,” the advisory issued at 9:04 a.m. said.

The possibility of strong to severe thunderstorms beginning this afternoon prompted the weather service to later issue a special weather statement.

“The strongest storms this afternoon could produce strong gusty winds, frequent lightning, intense downpours and funnel clouds,” the statement said.

Forecasters said there was also the possibility of hail “the size of quarters or larger.”

“While not everyone will see intense weather, you should be prepared to move indoors quickly if the weather appears threatening or thunder is heard,” meteorologist Robert Ballard said.

“Those with outdoor plans should have an immediate way to get watches or warnings that may be today through Saturday,” he said.

Clouds producing moderate to heavy showers over Maui are visible in this infrared satellite image taken at 9 a.m. today. NOAA/NWS image.

Some flooding was already occurring on Maui this morning as a result of moderate to heavy rain over with windward and south slopes of Haleakela, the weather service said.

Park rangers reported that Oheo Gulch remained closed because of elevated stream levels.