(BIVN) – The National Weather Service in Honolulu has issued a Flash Flood Watch for the Big Island from 6 p.m. HST this evening through Wednesday afternoon. In addition, the summits of Mauna Kea and Mauna Loa are under a Winter Weather Advisory as well as a High Wind Warning.

“An upper level trough will produce heavy showers and thunderstorms along a band of moisture that will slowly move down to the Big Island tonight and Wednesday,” forecasters stated on Tuesday. “The main threat for flash flooding will be over windward slopes.”

“Some of these thunderstorms could be strong, especially over coastal waters,” a Tuesday forecast discussion stated.

At the summits, where freezing levels will drop to around 9,000 feet, winter weather is expected on the high elevations of Haleakala on Maui tonight, with the chances for winter weather shifting to Mauna Kea and Mauna Loa late tonight and Wednesday.

Periods of freezing rain with snow showers are expected. “Ice will result in difficult travel conditions,” the National Weather Service said. “Total snow accumulations of up to three inches and ice accumulations up to one tenth of an inch are expected.”

A High Wind Warning is also in effect for the summits until 6 p.m. Wednesday. West winds will increase to 55 to 65 mph with localized gusts over 80 mph tonight, forecasters say.