Hawaii is in for a bit of a blow. 

But just how strong the winds from Tropical Storm Guillermo will be depends on the path it takes. 

If it keeps to its track as of Wednesday night, the isles will escape the worst of the weather, forecasters say. 

But if it veers to the south — as it did by 80 miles Tuesday, the islands could experience tropical storm force winds of 39 mph or higher, probably on Thursday, according to the Central Pacific Hurricane Center. 

Wednesday will likely be a regular tradewind day, with passing clouds and showers affecting windward and mauka areas, said Norman Hui, a meteorologist with the hurricane center. 

“There is uncertainty how close it would get to the islands,” he said of Guillermo. “That’s the iffy part.” 

With maximum sustained winds of 60 mph, the storm was centered 260 miles east of Hilo and 435 miles east of Honolulu as of 5 a.m. Wednesday. It was churning west-northwest at 9 mph. 

On its current track, it was expected to pass 160 miles north-northeast of Hawaii island on Wednesday night and 90 miles north-northeast of Maui on Thursday, forecasters said. 

All islands are under a flash flood watch through 6 p.m. Thursday. Maui and Hawaii counties were under a tropical storm watch, and a tropical storm warning was in effect Tuesday for offshore waters 40 to 240 nautical miles out. 

“Moisture from Tropical Storm Guillermo will move over the state through Thursday bringing the possibility of heavy rain and flash flooding,” the weather service said.

East shores of Hawaii, Maui, Molokai, Oahu and Kauai are under a high surf warning with waves of 10 to 15 feet expected through 6 a.m. Thursday.

Honolulu Mayor Kirk Caldwell said Guillermo appears to be tracking north of the islands, but “it doesn’t mean, though, that we’re in the clear,” adding, “It means that we still need to be vigilant.” 

The city does not plan to open any shelters, the mayor said at a news conference at the Department of Emergency Management. But he urged people to pay attention to weather updates on TV, radio and newspaper. 

Department of Facility Maintenance Director Ross Sasamura said crews are clearing drainage canals and continue to work on clearing stream mouths. He said the city is focused on eight areas, and he expects them to be completed by Thursday. 

The National Weather Service issued a flash flood watch for Hawaii island and Maui as Guillermo approached the state. 

Guillermo should make its closes pass to Oahu sometime after 2 p.m. Thursday and Kauai early Friday, the hurricane center said. It was expected eventually to weaken into a tropical depression, likely by Saturday.