The entire island chain of Hawaii is being put on alert for downpours heavy enough to trigger flash flooding along with gusty winds into the middle of the week.
"A cold front will stall between Maui and the Big Island Monday and Tuesday of this week," AccuWeather senior meteorologist Mike LeSeney said. "The combination of this stalled front and a storm high in the atmosphere will produce the threat for flooding rainfall across portions of Oahu, Maui and the Big Island."
|The lighter shading to the west of Hawaii on this AccuWeather RealVue&trade Satellite image is indicative of clouds associated with an approaching front on Sunday night, local time. (AccuWeather)|
The front already has a history of producing heavy rainfall over the Na Pali Coast on Kauai, where the National Weather Service said in their local discussion that an estimated 4 inches of rain had fallen by Sunday afternoon.
Advisories, watches and warnings are in effect across the state for impacts ranging from flash flooding to gusty winds and high surf.
"The heaviest rainfall will be on the windward side of the mountainous areas of the islands with an AccuWeather Local StormMax&trade rainfall of 10 inches expected," LeSeney said.
Rainfall of this magnitude can trigger flash flooding as well as mudslides in the higher terrain, which can lead to further damage and clog roadways with mud and debris.
Motorists are urged to never attempt to cross a flooded roadway as the water may be deeper and moving along at a faster pace than it appears and the ground underneath could be compromised.
Even in the absence of flooding and mudslides, the heavy rainfall itself will be enough to slow travel and put a damper on people's outdoor plans.
"The storm system will also produce strong north to northeasterly winds, rough surf and choppy seas," LeSeney said.
Wind gusts of 20 mph to 30 mph with localized gusts past 40 mph are possible into Monday night, with locally breezy conditions lingering through Tuesday.
Since the ground will be more unstable and saturated due to the heavy rainfall, these winds could increase the threat of localized tree damage and power outages.
The strong winds will stir up seas that will be extremely hazardous for small craft, bathers and even more experienced surfers.
"The storm will unwind and dissipate as it slowly drifts westward at midweek with the wind and waves diminishing later this week," LeSeney said.
Forecasters expect a typical easterly trade-wind shower pattern to resume across the island chain as the storm pulls away during the latter half of the week.