@FLOTUS/Twitter

First Lady Michelle Obama is ringing in her 50th year with a bang. She debuted a new hairdo, and fresh set of bangs, in a photo posted on her new @FLOTUS Twitter account today.

Before the inaugural festivities get underway, the Obama family celebrates another important milestone: the first lady's birthday.

Michelle Obama turns 49 today and, if previous years are any indication, President Obama will likely take his wife out to dinner in Washington tonight.

While there is no such event on the president's public schedule, the Obamas have dined out on the first lady's birthday for the past four years.

The list of restaurants visited on her birthday reads like a Zagat guide for fine dining in Washington. The tradition started in 2009 with a visit to the nearby Equinox restaurant. Just across Lafayette Park from the White House, the restaurant is known for its regional and seasonal cuisine.

The next year it was Restaurant Nora, which boasts of being the first certified organic restaurant in the country.

In 2011, the president took his wife to celebrity-chef Wolfgang Puck's restaurant The Source for dinner on her 47th birthday. They stayed close again last year, crossing the park for a steak dinner at BLT Steak.

Eddie Gehman Kohan, who keeps close tabs on the Obamas dining and White House food initiatives on her blog Obama Foodorama, notes that the chef who serves Michelle Obama's birthday dinner could end up working for the administration.

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All four chefs that have prepared her birthday meal in the past have gone on to participate in Obama's Let'sMove! initiative or been named as members of the State Department's American Chef Corps.

Whether it leads to a White House gig, a visit from the first family gives a local restaurant a boost.

"Businesses have a big spike when the president and first lady go out," blogger Kohan told ABC News. "By the end of it, there's always a crowd outside the restaurant. … In the past, the crowds have sung Mrs. Obama 'Happy Birthday.'"

The birthday dinners are always off the record and kept secret until the president and first lady arrive at the restaurant. Unlike the usual drop-by, restaurants are usually given a heads up when the Obamas are coming for a special occasion or birthday dinner, according to Kohan.

Secrecy remains a top priority, however, and the White House asks restaurants not to discuss publicly what the Obamas dine on.

As for where they might be headed tonight, Kohan said "it's dangerous to predict." The president and first lady have yet to make a repeat visit to a D.C. restaurant for a formal excursion.

Asked how Mrs. Obama intends to celebrate, White House Press Secretary Jay Carney just smiled and said "I don't want to ruin the surprise."