Updated 1 p.m.

Maybe the ice has finally thawed?

The Old Senate Chamber, where senators met in July to settle a long-simmering dispute over U.S. Senate rules. (Pablo Martinez Monsivais/AP)

Just a few weeks after 98 senators gathered for an unprecedented meeting in the Old Senate Chamber to settle a long-simmering dispute about the rules of the U.S. Senate, all 100 senators are scheduled to meet again Thursday for what Democratic aides describe as a "bipartisan caucus meeting" and others are calling an informal luncheon.

Several senators of both parties requested the meeting, but much of the credit goes to Sens. Roger Wicker (R-Miss.) and Johnny Isakson (R-Ga.). The two are co-hosting the lunch along with Sens. Mark Pryor (D-Ark.) and Jeanne Shaheen (D-N.H.), and are inviting colleagues to come dine on food prepared by Barbeque One, of Marietta, Ga. -- Isakson's hometown.

Much of today's meeting derives from Senate Republican tradition, which dictates that every Thursday, a different senator is responsible for selecting the lunch menu. Last year  Isakson decided on his appointed day that he also wanted to invite his Democratic colleagues, and members of both parties attended, his aides said.

Wicker proposed the rare meeting in the Old Senate Chamber a few weeks ago in order to ease tensions between party leaders and avoid a standoff over how the Senate confirms Executive Branch nominees. Today he's teaming up with Isakson to serve barbecue at the meeting, which is being held in the Russell Senate Office Building, aides said.

Although all 100 senators are invited, there is no guarantee that they will all attend, as many often skip weekly party luncheons to attend to other events. Two senators, Shaheen and Marco Rubio (R-Fla.), skipped the meeting a few weeks ago due to personal reasons.

The meeting comes during a busy final full day of deliberations in the Senate before lawmakers leave town for a five-week summer recess. The day is scheduled to begin with a confirmation vote for Raymond Chen to serve as the U.S. circuit judge for the Federal Circuit.

Then, senators are expected to vote to end debate on a transportation spending bill. But Senate Republicans may succeed Thursday in killing the measure, which proposes to cancel automatic budget cuts -- known as "the sequester" -- entirely. (House Republican leaders abruptly pulled their version of the bill on Wednesday.)

Later Thursday, the Senate is expected to vote to confirm Samantha Power to serve as the next U.S. ambassador to the United Nations. The Power vote will cap a notably productive week on the confirmation front, as the Senate this week confirmed James Comey to lead the FBI and B. Todd Jones to lead the Bureau of Alcohol, Tobacco, Firearms and Explosives. Several committees advanced other nominees who will get  votes after the August recess.

Paul Kane contributed to this report.

Follow Ed O'Keefe on Twitter: @edatpost