The Bureau of Meteorology says a flood watch has been issued for Cape York Peninsula with possible rainfall totals of up to 250 millimetres as it moves overland to the west.

Tiffany has weakened to a category one system and is expected to weaken further as it moves across the peninsula before reaching the Gulf of Carpentaria on Tuesday morning.

"Far north Queensland is experiencing the power of Tropical Cyclone Tiffany, and these impacts will be felt for the next day or so throughout north Queensland and then into the Northern Territory"' senior meteorologist Dean Narramore said.

"These tropical systems intensify quickly and can shift direction very quickly as they develop, so the Bureau will be updating our warnings and advice to the community and our emergency services colleagues across Queensland and Northern Territory."

The cyclone formed in the Coral Sea and crossed Queensland's northern coastline on Monday morning on a westward track.

Authorities are confident adequate measures are in place for Cooktown and Lockhart River.

"Our preparations are very good. We have high confidence in the shelters and the structures in the areas that are impacted," State Disaster Coordinator Steve Gollschewski said.

"We have factored into our planning the cases of COVID that are currently in the Cape and that is well-covered in our operational planning.

"Similarly for the emergency response that may need to come afterwards if we have loss of power, we have testing of those people in place before they go in, all of that is looking pretty good at this stage."

Lockhart River Council CEO David Clarke said the community are "alert but not alarmed" as the system passes to the south.

"Little bit of rain here, no wind. We're on the north side of the system - so it's the safe side," he told AAP.

But the Torres and Cape Hospital and Health Service said there would likely be changes to their vaccine rollout as communities bunker down.

The bureau is warning communities to expect wind gusts between 90 and 125km/h and heavy-to-intense rain before Tiffany moves and re-intensifies on its path towards the Northern Territory coast.

Severe tropical cyclone coastal impact in the Northern Territory is possible on Wednesday or Thursday, the bureau says.

Queensland Premier Annastacia Palaszczuk said impacted residents should keep up to date with emergency alerts via the BOM.

Tiffany is the third cyclone of the season in the Coral Sea and the first to make landfall in Queensland.

Category two Cyclone Seth weakened into a low before crossing the Wide Bay-Burnett region's coast on Friday and dumping up to 600mm of rain in some areas, causing major flooding in and around the city of Maryborough.

A 22-year-old man was found dead in a ute submerged in floodwaters on Saturday, while police were searching on Monday for a 14-year-old girl who was swept away in a torrent on Friday night.

Large waves whipped up by Seth last week damaged coastal structures and eroded beaches in southeast Queensland.

In early December, another low intensified into category two Cyclone Ruby but moved east across the Pacific.

Australian Associated Press