A flash flood watch went into effect this evening due to the threat of locally heavy rainfall and thunderstorms statewide.

The National Weather Service has the flash flood watch in place from this evening through late Friday night and covering all islands from Niihau to Hawaii island due to an upper-level disturbance moving into the area.

The NWS has also issued a winter storm watch for Hawaii island summits, warning of heavy snow from this evening through Friday night.

Forecasters said up to 6 inches of snow accumulation is possible above 12,000 feet. Also, that heavier bursts of snow could be accompanied by gusty winds and low visibility.

Anyone planning travel to the summits should consider postponing their trips until the weather improves.

Today’s forecast, meanwhile, includes mostly cloudy skies and likely showers for the windward and mauka areas, and highs from 77 to 82 degrees. Tonight’s skies are also cloudy, with the expected, heavy rainfall and slight chance of thunderstorms.

Tradewinds will continue — at varying speeds — up to 20 mph for Maui and Hawaii island, and at 5 to 15 mph on Kauai and Oahu.

Surf for all sides of the islands remains below advisory levels today through Friday.

Surf along north shores lowers from 2 to 4 feet today to 1 to 3 feet Friday and remains flat to 2 feet for west shores today and Friday.

Surf on south shores remains at 1 to 3 feet today and Friday, while surf on east shores rises slightly from 2 to 4 feet today to 3 to 5 feet Friday.

Forecasters say conditions are expected to improve, with a return to a more typical tradewind pattern this weekend.