How do you get the first post-inauguration interview with the president? How do you get the vice president to shake your hand? You yell at them from the crowd during the parade, apparently. That's what NBC weather man Al Roker did this afternoon from the sidelines of Pennsylvania Avenue. "Mr. President, Mr. President, Mr. President," Roker yelled. "How's it going?" 

"It's going great," the president shouted back, with this thumbs-up:

Roker was pretty proud of himself: 

And NBC News was happy, too: 

Here's the money clip:

And here's the full video, with Brian Williams and David Gregory egging him on: 

Roker had even greater success yelling at politicians a few minutes later, when Vice President Joe Biden ran over and shook his hand. 

Here's a clip of that success:

And full video, with drum roll:

Roker's response? "Yes!" Ditto from the NBC control room:

But Roker shouldn't feel that lucky. Biden is shaking a lot of hands on the parade route. 

Stay tuned to our live blog for more updates from the parade and the balls.