Tropical Storm Flossie will likely pass over the Big Island on Monday, bringing heavy rains and sustained winds of 30 to 40 mph.
The storm is expected to hit the windward and north sides the hardest with flooding and power outages possible across the isle.
Flossie is expected to continue to weaken as it approaches from the east, becoming a “low-end tropical storm” by the time it arrives, Michael Cantin, warning coordinator meteorologist with the National Weather Service, said Saturday afternoon.
But it still could dump as much as 6 to 10 inches of rain, with higher amounts localized in the windward areas, he said.
Wind gusts are possible, and they could reach 50 to 60 mph. Surf may be as high as 12 to 18 feet, mainly on east-facing shores.
Flossie is expected to arrive around mid-morning Monday but the timeline could change.
Cantin said the biggest impact of the storm will rain, which will focus on the east and northeast sides of the island.
Most of the rainfall is concentrated on the north side of the storm.
“If it remains like that, the strongest wind and rainfall will be on the northern half of the storm,” he said.
“Leeward on the Big Island area may not see as much.”
“A lot of coins are up in the air on this one,” Cantin added.
Winds bring the potential for power outages and minor structural damage, he said.
“These are not hurricane-force winds,” Cantin said.
“They are not going to shred your house apart but they could cause minor damage.”
Large storm surges are not expected, and Hawaii Civil Defense is not planning to activate its warning sirens.
Flossie is expected to be downgraded to a tropical depression by Tuesday as it moves south of Oahu.
“As it passes the Big Island and Maui, we expect the terrain to break it up … weaken fairly rapidly,” Cantin said.
As of Saturday, the storm was producing 50 mph sustained winds, down from 60 mph.
Residents in wind-prone parts of the island may want to prepare, Cantin said.
“If you’re in an area that gets wind, you may want to protect your home a little bit,” he said.
“I wouldn’t suggest boarding up right now.”
Flossie is the same name given to the hurricane that brought tropical storm winds to South Point in 2007.
That was the last time the island experienced storm-strength winds, according to the weather service.
Email Tom Callis at email@example.com.