Winter Storm Warning issued in Hawaii as Kona Low slams state with brewing flood threat, snow

Active winter weather is strengthening across Hawaii as a powerful, cold low-pressure system develops through early Tuesday, bringing heavy rain, thunderstorms, and winter conditions.

The low-pressure system, known as a Kona low, is currently located north of Hawaii and is drifting south of the state while an active associated rainband continues to grow, causing dangerous weather across the islands.

WHAT IS A KONA LOW?

So far, low-level winds are merging over O'ahu and Maui County, and a few thunderstorms have formed over offshore waters north of O'ahu and west of the Big Island.

Within the next few days, a persistent southeasterly flow will continue to push deep tropical moisture across the mountain slopes of the Big Island and Maui County, creating a risk for heavy, prolonged rain across the area.

The FOX Forecast Center says thunderstorms and locally heavy rain remain possible as the cloud band associated with the Kona low moves across the state.

It is predicted that 1 to 2 inches of rain will impact areas that are prone to flooding. A Flood Watch will remain in effect through Monday afternoon. 

In addition to heavy rain, a Winter Storm Warning is in effect through early Tuesday morning for the summits of the Big Island.

The falling temperatures at the summits, combined with the tropical moisture, will create ideal conditions for accumulating snow and ice. This type of precipitation will cause significant icing on the summits' roadways. 

The FOX Forecast Center predicts up to six inches of snow is likely.

In addition to the snow and ice, high wind conditions are expected at the summits, with wind gusts of 50–60 mph and occasional gusts up to 75 mph possible at lower elevations.

All these factors combined will greatly reduce visibility, with near-zero visibility possible at times.

HOW TO WATCH FOX WEATHER

By midweek, the Kona low will weaken as it drifts west of the state, but a weak, mild disturbance is expected to move in later in the week, bringing more precipitation.