(BIVN) – Following last weekend’s storms that flooded the State of Hawaii, in particular Kauai where the recovery effort continues, a new weather system is threatening the islands.

Hawaii County Civil Defense issued an alert message on Wednesday, in preparation of heavy rainfall and thunderstorms forecasted for Hawaii Island starting tonight through Saturday.

“Due to last week’s heavy rain, residents in flood-prone areas are advised to be on the alert for possible flooding conditions,” civil defense stated. “Motorists are urged to exercise caution while driving. Road closures may occur without notice. Thunderstorms are expected. If lightning threatens your area, the safest place to be is indoors.”

The National Weather Service in Honolulu has already issued a Flash Flood Watch for the entire state, in effect Thursday morning.

According to this morning’s NWS statement:

Deep moisture associated with an old frontal boundary lingering across the state in combination with an upper level trough moving through the area, will bring the threat for heavy rainfall and flash flooding. The heaviest rainfall is expected to fall from Oahu eastward to the Big Island. Even though widespread heavy rainfall is not expected on Kauai, many areas have recently received a significant amount of rainfall and the soils remain saturated. As a result, even moderate rain falling for a extended period in these harder hit areas of Kauai could lead to Flash Flooding.

In addition, a Winter Storm Watch has been issued for Mauna Kea and Mauna Loa summits. “Heavy snow possible,” forecasters wrote. “Storm total snow accumulations of 6 to 12 inches may occur,” on Big Island Summits above 12,000 feet.