President Barack Obama will be gracing us with his presence this afternoon and this evening, leaving in his wake a sea of stalled traffic and frustrated pedestrians told they can't cross the street without walking a half mile out of their way in a tornado. Air Force One is expected to touch down at JFK airport at 3 p.m.; from there Obama will be flown by helicopter to the Wall Street heliport on the East River. As a result, East River ferry service will be delayed and closed at Pier 11 between 3 p.m. and 4 p.m. and again between 10:10 p.m. and 11 p.m. Here's what else you should be aware of:

Forget about the FDR—Obama will take that on his way to Times Square to tape an appearance on David Letterman's show. According to Gridlock Sam, 53rd Street will likely be closed for most of the afternoon, and Obama will "likely use 42nd St to 8th Ave; then up to 54th St & Bway near Ed Sullivan Theater" with short Avenue ‘freezes' from 1st to 8th Avenues starting at 4 p.m. After that the President is off to the Waldorf Astoria hotel for a reception at 7:40 p.m. (The White House says 200 donors are expected to attend, with tickets starting at $12,500 per family.)

Then it's off to another, smaller private fundraiser hosted by Beyonce and Jay-Z at the 40/40 club by Madison Square Park, with tickets costing $40,000 each. He's expected to arrive at 9:45 p.m., and Gridlock Sam says you can expect West 25th Street between 5th and 6th Avenues to be closed most of the day. And soon after, sometime between 10-10:30 p.m., Obama's motorcade will hit the FDR again to go back to the Wall Street heliport. So if you're lucky enough to get a taxi during TONIGHT'S TORNADO, be sure your cabbie knows to stay the hell away from midtown and the east side tonight.