At a press conference addressing Hurricane Irene this afternoon, Mayor Bloomberg issued a mandatory evacuation order for residents of Zone A, which as this PDF map indicates, includes areas of Alphabet City (Bowery Boogie has an East Village and Lower East Side detail of the map). All affected residents are ordered to evacuate by 5 p.m. tomorrow. Subways, buses, the Long Island Railroad, and Metro-North will cease operation at noon tomorrow as well.

Gothamist quotes Mayor Bloomberg as saying,  “Nobody is going to get fined and nobody is going to go to jail, but if they don’t evacuate they could die.”

As noted this morning, the nearest evacuation centers are at Seward Park High School (350 Grand Street) and Baruch College (East 23rd Street and Lexington Avenue).

Jules Martin, Vice President for Public Safety at NYU, announced in an e-mail that all of Sunday’s classes, events, and other scheduled activities have been canceled, and Move-In Day has been postponed till Monday.

Canceled events on Sunday include all street fairs, Fringe Festival performances, the Bowery music tour we told you about, the Greenmarket, and more. The Lo-Down has a list of Lower East Side cancellations.

Stuy Town Living has posted some readiness tips.

We’ll share more news as it comes in.

Update | 4:53 p.m. A spokesman for the New York City Housing Authority tells The Local that at the Campos, Riis, Smith, Wald, Baruch and Haber Houses, staff members have posted signs in multiple languages instructing residents to evacuate before they are hit with possible power outages. According to NY1’s rundown of developments, “Consolidated Edison is making preparations for the possibility of Hurricane Irene wiping out the city’s power.”

The city has ordered NYU Langone Medical Center to evacuate Tisch Hospital and the Rusk Institute of Rehabilitation Medicine by 8 p.m. this evening. A telephone recording says, “We will be discharging patients as early as possible as determined safe. For patients who cannot be safely discharged we will be transferring them to other hospitals in the region.”

Update | 5:44 p.m. Among the businesses that will be closed on Saturday and Sunday, per their Twitter feeds, are the Tenement Museum, Mercury Lounge, Peels, and Luke’s Lobster, which is selling lobster rolls for just $10 tonight in order to reduce inventory. New York Theatre Workshop has cancelled its weekend performances. Ray’s Candy Store, meanwhile, has vowed to stay open.