PROVINCETOWN (CBS) — The United States Coast Guard is conducting a search off Provincetown after a fishing boat sank early Monday morning. Rescuers are looking for four fishermen believed to be in the water.

The 82-foot fishing vessel Emmy Rose, based out of Portland, Maine, sank about 20 miles northeast of Provincetown, officials said. The Coast Guard received an emergency radio beacon from the Emmy Rose at 1 a.m.

Natasha Dobson says her uncle, Jeffery Matthews, is among the missing. “A lot of us are just in shock right now we don’t know what the outcome is going to be we are just all trying to have hope,” Dobson said.

A helicopter crew and Coast Guard Cutter immediately responded to the vessel’s last known location, where rescuers found debris and an empty life raft.

“We saw the raft that was deployed and upright, so that was encouraging,” said Coast Guard Commander Ian Hurst. “We were hoping that we would find some people inside that raft.”

The Emmy Rose (Photo credit: Gloucester Boats)

The helicopter, a plane and three Coast Guard boats were part of the search. The helicopter had to return to land as severe weather moved through the area Monday morning, sparking a tornado warning for parts of Cape Cod. The search resumed as the weather improved.

Only the 210-foot Coast Guard Cutter remained on the water overnight. The bigger search effort will resume Tuesday morning.

“My Uncle Jeff has been lost at sea before and found so you know we are feeling hope for him, we’re feeling hope for the other crew members,” Dobson said.

Maine Sen. Angus King said he was “praying for the safe return” of the fishermen and the safety of the rescuers.