Updated: 3:01 p.m.

A bipartisan group of Senators will tour the Gulf Coast on Friday to survey the damage caused by April’s massive oil spill.

Members of the group include Democratic Sens. Benjamin Cardin (Md.), Barbara Mikulski (Md.) and Jeff Merkley (Ore.) as well as Republican Sen. David Vitter (La.). The group is expected to view the coast by helicopter and tour Grand Isle, La., a barrier island in the Gulf.

Also on the trip are a handful of White House officials, including Environmental Protection Agency Administrator Lisa Jackson and representatives from the Department of Interior, U.S. Geological Survey, Army, and National Oceanic and Atmospheric Administration.

A group of scientists tapped by the federal government to assist with the response to the Deepwater Horizon explosion predicted Thursday that as much as 30,000 barrels of oil are spewing into the Gulf daily. That estimate has fluctuated since the explosion, but the most recent count confirms the BP oil spill far surpasses that of the Exxon Valdez spill off the Alaska coast in 1989.

President Barack Obama met Thursday with family members of the 11 workers who died in the April 20 explosion, and he announced that BP agreed to speed up payments to the relatives and others whose livelihoods have been affected by the spill. BP Chief Executive Tony Hayward is scheduled to testify before the House Energy and Commerce Committee next week and will likely discuss the payments issue.

Adm. Thad Allen, the former Coast Guard commandant who is leading the Gulf Coast response effort, also requested that the top BP executive meet next week with Obama and White House officials to discuss the cleanup and recovery efforts.

Next week, Obama will make his fourth trip to inspect the spill and cleanup efforts, the White House announced Friday. However, this time he will stay overnight, arriving Monday and then leaving the next day after making stops in Florida, Alabama and Mississippi.