HONOLULU -- The National Weather Service issued a flash flood warning for the island of Oahu Thursday morning as a line of heavy showers and thunderstorms made its way to the island, with lightning and thunder over the downtown area. More heavy showers were continuing to form to the southwest.

Kauai and Oahu also remained under a severe thunderstorm watch, which means conditions could favor thunderstorms that produce hail and damaging winds of 58 mph or more.

Hawaii remains under the threat of locally heavy showers and thunderstorms for at least the next few days. The entire state remains under a flash flood watch until 6 pm Friday, as any heavy rain falling on saturated ground will result in flash flooding.

At about sunrise Thursday, Kauai was being affected by a line of thunderstorms with rainfall rates of up to 2 inches per hour and occasional wind gusts near 30 mph. Most of the heavy showers were reported on the southern end of the Garden Isle, with Omao getting 0.86 of an inch of rain between 5 a.m. and 11 a.m. Port Allen received 0.79 of an inch, while Kalaheo reported 0.71 of an inch of rain during the same period. On the north shore, a Hanalei area resident reported steady rainfall with thunder, but no downpours.

An upper level Kona low west of Hawaii remains responsible for the continued wet and unstable weather. At the surface, a trough northwest of the islands is drawing up more moisture from the southwest. The trough is forecast to move closer to the islands, bringing a higher chance of heavy rain and isolated thunderstorms late Thursday and perhaps into Friday.

Some of that precipitation may fall as snow on Mauna Kea and Mauna Loa on the Big Island. The summits of both mountains are under a witner storm watch until Friday evening, with up to a foot of new snow expected. The road to the summit of Mauna Kea was reported closed at the visitor center, 9,000 feet up.

The National Weather Service has pegged Feb. 19 as the start of the current unstable weather the islands have been experiencing. That would make Thursday the 40th day of wet weather.

And it's not over yet. Forecast models say we may see a bit more sunshine over the weekend, but conditions will still be right for scattered showers through Monday.