Aug. 28 (Bloomberg) -- More than 10,000 people may gather tomorrow in New York’s Prospect Park to celebrate what would have been the 51st birthday of the late pop star Michael Jackson at a “block party” organized by filmmaker Spike Lee.

Heavy rain and thunderstorms predicted by the National Weather Service won’t stop the Brooklyn party, Lee’s company said. “Saturday’s event is going full steam ahead rain or shine,” according to a message posted yesterday on the Twitter feed of 40 Acres and a Mule Filmworks Inc.

Jackson, whose 1982 “Thriller” is the best-selling album of all time, died June 25 from an overdose of the anesthetic propofol and two other sedatives, according to a search warrant unsealed in Houston. Brooklyn’s senior elected official, Borough President Marty Markowitz, will proclaim tomorrow “Michael Jackson Day.”

The event will be a “Brooklyn-style block party,” Lee told The Root, an online magazine of black American culture. “It’s going to just be how we do it, Brooklyn style. I’ll leave it at that. It’s going to be a joyous, festive, celebratory party.”

As many as 30,000 people or more may show up to celebrate on the Nethermead, a 15-acre lawn in Prospect Park, said Eugene Patron, a spokesman for the Prospect Park Alliance, the not-for- profit group that manages the park.

Severe weather that is determined to pose a hazard, such as high winds and lightning, may force organizers to cancel the event, Patron said in an interview today.

Lee paid $11,000 for a permit to hold the party, Trish Bertuccio, a spokeswoman for the city’s parks department, said in an interview. The organizers have provided 50 portable toilets, she said.

Brooklyn-born Lee worked with Jackson when he filmed the singer’s music video for the song “They Don’t Care About Us,” some of whose words were changed by Jackson after the recording was released, in response to accusations that the lyrics were anti-Semitic, the New York Times reported.

To contact the reporter on this story: Peter S. Green in New York at psgreen@bloomberg.net.

Last Updated: August 28, 2009 11:53 EDT