Hawaii island is bracing for the impact of Tropical Storm Calvin, which could make landfall as early as tonight.

Although Calvin was showing some signs of weakening Monday, it was still expected to deliver heavy rain, high surf and tropical storm-force winds.

The Central Pacific Hurricane Center on Monday night issued a tropical storm warning, which means that tropical storm-force winds (39-73 mph) are expected within the next 36 hours.

Also posted was a high-surf warning for the northeast shoreline from Upolu Point in North Kohala to South Point in Kau for rising surf tonight, as well as a flood watch for the entire island beginning tonight.

Officials were urging Hawaii County residents to prepare for flash flooding, damaging winds and dangerous surf.

As of Monday night Calvin was moving swiftly at 21 mph on a track that appeared to set its sights on the South Point area. But nearly all of Hawaii island remained in the storm’s cone of uncertainty, and tropical storm-force winds were still reaching out over 100 miles.

Forecasters said the Big Island was expected to be pounded by as much as 10 inches of rain, mainly on the windward side of the island, while the rest of the chain likely will see 1 to 4 inches.

“This rainfall could lead to localized flash flooding and mudslides,” forecasters said.

As of Monday night Calvin’s maximum sustained winds were near 45 mph with higher gusts.

A rapid increase in surf is expected along east- facing shorelines exposed to the swells today and Wednesday, forecasters said, and the rising surf is likely to produce life- threatening conditions along exposed shorelines.

Mayor Mitch Roth on Monday announced a number of safety measures in anticipation of the storm.

“While we hope for the best, it’s crucial that we plan for the worst,” he said in a statement. “The safety of our community is our top priority, and we are taking all necessary measures to ensure that everyone remains safe and well-prepared throughout the duration of the storm.”

Here are some of the measures:

>> County camping permits islandwide will be canceled from today through Wednesday to avoid potential risks with camping during adverse weather conditions.

>> Starting today, Waipio Valley Access Road will be accessible only to residents and farmers in case swift evacuations are required and to prevent any unnecessary congestion on the roadways.

>> Two emergency shelters were being readied in the Kau district. The Robert Herkes Gymnasium and the Naalehu Community Center will serve as safe locations for residents seeking shelter during the storm. These shelters will be staffed with trained personnel and equipped with essential supplies to accommodate residents. The shelters are pet-friendly, requiring owners to provide a carrier, food and other supplies for their animals.

>> The Department of Public Works, Building and Engineering divisions will not conduct any permit or project inspections Wednesday.

Hawaii County Civil Defense officials were reminding residents Monday to prepare emergency kits, secure loose outdoor items and stay informed about weather conditions through official channels. Also, boat owners and those with shoreline property should complete preparations by this evening.

Calvin is forecast to gradually weaken during the next several days.