Authorities had moved to suspend all flights and ferry services ahead of the storm, which officially made landfall in the Pak Panang district of Nakhon Si Thammarat province around 3:30 p.m. local time (3:35 a.m. ET), with maximum sustained wind speeds of 95 kilometers per hour (59 mph), according to the Joint Typhoon Warning Center.

Some of the country's most popular tourist destinations , including Koh Samui, Koh Phangan and Koh Tao islands, along with islands in the Andaman Sea such as Phuket and Koh Phi Phi -- made famous by the movie "The Beach" -- are expected to be affected by the storm during what is peak holiday season.

"It's quite scary being here because we don't know what's going to happen and there is no way to leave," American tourist Miranda Abidyer, 26, who is stranded on Koh Samui island, told CNN.

Abidyer, who traveled to the island with her young family to celebrate her husband's 30th birthday, said they had a flight scheduled for Friday but it was canceled and ferry services have also been suspended. She said they hadn't received any information from local authorities about the storm or what they should do. They now plan to wait it out in their private villa, which is about 1 kilometer (0.6 miles) from the beach.

"We will hide in the bathroom if the storm gets that bad. But all we can do is wait," said Abidyer.

It is highly unusual for tropical storms and typhoons to make landfall in Thailand. The last time a tropical storm made landfall in Thailand was in 1962, when Tropical Storm Harriet claimed 900 lives. The only typhoon ever to make landfall in the Southeast Asian nation was Typhoon Gay in 1989.

The district chief of Koh Samui, Kittipop Roddon, told CNN by phone Friday that there are about 20,000 tourists staying on the island, which is the second largest in Thailand.

"The island is now totally cut off from the mainland, all kinds of transportation (to mainland) have been suspended since yesterday," he said, adding that there is enough food and supplies on Koh Samui to last through the storm.

Those left are now preparing to ride out the storm, with residents on Koh Samui boarding up houses with wooden planks. By Friday, the roads on the island were quieter and store shelves emptier, witnesses told CNN.

But it's those on some of the smaller islands that could be the most vulnerable. The district chief of Koh Phangan and the popular diving island of Koh Tao told CNN that he was concerned that any emergency rescue operations would be more difficult on Koh Tao due to its remoteness. He said 15,000 tourists remain on Koh Phangan and about 4,000 on Koh Tao.

Locals clear the shoreline Friday in preparation for the approaching storm in Pak Phanang, in the southern province of Nakhon Si Thammarat.

Tourist Danielle Dickinson told CNN she was stuck on Koh Tao. "Got the ferry here on Wednesday which is annoying as we weren't told a storm was on its way," she said. "The rain is torrential and winds are getting stronger."

Thousands of residents living in coastal areas were evacuated to storm shelters on Thursday, according to Thailand's Disaster Prevention and Mitigation agency. Some 5,700 people were moved to safety in the province of Nakhon Si Thammarat, on the country's east coast, which is among the areas expected to be hardest hit by the storm.

The agency's director general, Chyapol Thitisa, told CNN that for three days the army had been helping to evacuate those living in remote and coastal areas in the province and some coastal villages prone to storm surges have been completely emptied.

The Royal Thai Navy's only aircraft carrier has been deployed along with two other ships to assist with rescue and relief operations, according to broadcaster Thai PBS. It will reportedly take 15 hours for the ships to sail from their base to Nakhon Si Thammarat.

Waves crash into a pier in the southern Thai province of Surat Thani on Friday.

Thousands of tourists have also fled the islands, cramming onto ferries and specially chartered boats.

Nakhon Si Thammarat airport is closed, and Bangkok Airways announced the cancellation of all flights to and from Koh Samui on Friday "for safety reasons."

Torrential downpours have already dumped up to 200 millimeters (nearly 8 inches) of rain on some areas, with more expected. Strong winds on Thailand's gulf coast, which lies directly in the path of the storm, could bring waves up to 3-5 meters (10-16 ft), according to the Meteorological Department.

After crossing the Chumphon Archipelago and mainland provinces, the storm will move into the Andaman Sea, impacting the Andaman and Nicobar Islands with heavy rain and gusty winds before dissipating in the Bay of Bengal this weekend.

Holidaymaker Mandira Popat told CNN she was stranded on the small resort island of Koh Ngai, in the Andaman Sea, with her husband Akshyat Bhatia.

"There are extremely strong winds and sporadic showers currently with strong waves in the sea," she said. "Last night there were huge thunderstorms which lasted til 9 in the morning. People are staying indoors and away from the Andaman Sea since yesterday because the sea has been violent."

The couple have flights booked from Phuket on Saturday but no ferries are running to take them to the island, leaving them stuck on Koh Ngai, she said.

Chinese tourists disembark at Surat Thani airport in southern Thailand after tour operators were forced to suspend boats to tourist islands due to Tropical Storm Pabuk.

The storm is expected to bring strong winds, high waves and surf along with surge, and heavy rain with flooding. While the winds, surf and surge will be dangerous especially, to an area not used to seeing these types of storms, the most significant danger is the rain and flood potential.

Areas in the southernmost portion of Thailand could receive well over 250 millimeters (10 inches) of rain by the time the storm has passed. There is also the possibility of mudslides from the Phuket mountain range on the western side of the peninsula.

The province likely to be worst affected is Nakhon Si Thammarat, where Tropical Storm Harriet hit in 1962.