1:07 p.m. update: The president walked about a block along Eagle Drive through what can only be described as utter devastation. The elementary school was on his left as he stopped at a couple of piles of debris. Obama had a grim look on his face as he surveyed the scene.
1:03 p.m. update: "People here pride themselves on the Oklahoma Standard," the president said. He credited forecasters, first responders and teachers who shielded students.
1:01 p.m. update: The president arrived in Moore at 12:28 p.m. to tour one of the most devastated neighborhoods. Spectators waved on the sides of the roads during parts of the 20-minute motorcade.
1 p.m. update: President thanks Gov. Fallin, Moore Mayor Glenn Lewis, Rep. Tom Cole, Oklahoma City Mayor Mick Cornett, FEMA's Craig Fugate, Moore School District Superintendent Susan Pierce and Plaza Towers Elementary School Principal Amy Simpson.
12:59 p.m. update: The president gave remarks: "A picture is worth a thousand words."
"I'm speaking on behalf of the entire country," Obama said, adding that "fellow Americans are praying for you and thinking about you."
You are not alone, he said.
12:45 p.m. update: The president's motorcade includes several local police vehicles and an ambulance. Several police cars and sheriff's office vehicles can be seen around the area the president is touring. Television reports indicate military and U.S. Secret Service presence is evident.
12:32 p.m. update: President Barack Obama's motorcade has arrived in a storm-ravaged section of Moore. He is on foot, touring the area with other officials.
12:28 p.m. update: The president officially arrived at Tinker Air Force Base at 11:42 a.m. Sunday. He had switched to a black jacket. He left Air Force One and was greeted at the bottom of the stairs by Gov. Mary Fallin, whom he shook hands with and gave a hug. He also was greeted by Rep. Tom Cole (R-Moore), Oklahoma City Mayor Mick Cornett, Midwest City Mayor Jack Fry and Tinker personnel.
He then shook hands and spoke with some in the crowd of about 100 who gathered for his arrival. Many were Tinker personnel, both military and civilian, whose homes were damaged or lost in the tornadoes. About 350 Tinker families lost their homes.
12:25 p.m. update: White House spokesman Josh Earnest spoke to reporters about debris removal. He said, when the president signs a major disaster declaration, that often includes direct financial assistance to help state and local governments.
Not only was that provided as part of the major disaster declaration the president signed on Monday, on Tuesday the president approved additional assistance for the state in implementation of a Debris Removal Pilot Program.
Typically, debris removal assistance is provided with a 75 percent, and 25 percent federal/state cost-share.
Under the pilot program, the president authorized the federal share of the debris removal assistance to increase to 85 percent for the first 30 days and 80 percent for the second 60 days -- encouraging state and local governments to prioritize debris removal at the beginning of the recovery phase, which in turn increases access to affected areas and speeds other phases of recovery.
12:20 p.m. update: Other officials President Barack Obama met with on the tarmac at Tinker Air Force Base:
-Lieutenant General Bruce Litchfield, Commander, Air Force Sustainment Center
-Colonel Steven Bleymaier, Commander, 72d Air Base Wing and Installation Commander
-Chief Master Sergeant Brian Lavoie, Command Chief, 72d Air Base Wing
-Midwest City Mayor Jack Fry
-Rep. Tom Cole, R-Moore
-Oklahoma City Mayor Mick Cornett
-FEMA Administrator Craig Fugate
12:15 p.m. update: White House spokesman Josh Earnest briefed reporters aboard Air Force One about the president's trip and said preparations for the tornado began days ahead of its arrival in Moore, thanks in part to ever-improving weather forecasting technology, citing the work done by the National Weather Service. The NWS briefed national and regional FEMA personnel May 19, and FEMA was already in place before the deadly storm hit.
Earnest said tornado warnings were issued for Moore 36 minutes before the tornado struck, which is better than the average time of 12 minutes.
He also said FEMA has provided 43,000 meals,150,000 liters of water and thousands of cots, blankets and tarps.
"That support is not winding down. We will be standing with the people of these resilient communities as they come back stronger than ever."
He went on to say today is not a day for politics.
"That said, it is evident to any impartial observer here, what an important role the federal government can play in providing assistance to our people in their urgent time of need," Earnest said. "It's important for the people in these communities to understand that the entire nation is standing with them in their time of need."
Noon: President Barack Obama has arrived at Tinker Air Force Base and deboarded Air Force One. Obama was greeted on the tarmac by Gov. Mary Fallin, Rep. Tom Cole, R-Moore, and several other state officials. Obama met with several people beside the runway and then climbed aboard a vehicle to depart the base.
11:45 a.m. update: Obama is expected to be greeted by Gov. Mary Fallin and accompanied by Rep. Tom Cole, whose district includes Moore, one of the communities that was destroyed by tornadoes Sunday and Monday that killed 24 injured hundreds and caused damage estimated at more than $2 billion.
According to a White House official the president is expected to tour Moore.