PORTLAND — A strong thunderstorm forced the city to postpone its Fourth of July concert and fireworks display, but the show will go on Thursday.

City officials said the plan for the Stars and Stripes Spectacular on July 5 will be the same as for the Fourth, with a concert starting at 7:40 p.m. and the fireworks scheduled to go off at 9:20 p.m.

The forecast is more promising. The National Weather Service calls for partly cloudy skies in the evening and temperatures in the 60s after a partly sunny day with highs in the mid-70s.

The thunderstorm initially caused a delay in the events, with the concert pushed back to about 8:30 p.m. after lightning lit up the skies. The lightning was followed by a heavy downpour and strong winds, leading to the postponement of the evening events for a day.

The concert program will remain the same, with selections from John Philip Sousa, Aaron Copland, John Williams and Pyotr Tchaikovsky leading into the fireworks, to be shot from a barge off the East End.

The Great American Ice Cream Fest, a fundraiser featuring an array of treats from New England ice cream makers, was held before the storm hit Wednesday and will not be repeated on Thursday.

The East End boat launch, Cutter Street and parking lots on Cutter Street will remain closed until 6:30 a.m. Friday.

The following streets will be closed from 11 a.m. to 10 p.m. Thursday: the Eastern Promenade from Morning Street to Walnut Street; Wilson Street from Morning Street to the Eastern Promenade; Moody Street from Morning Street to the Eastern Promenade; Congress Street from Morning Street to the Eastern Promenade; Turner Street from Morning Street to the Eastern Promenade; Quebec Street from Emerson Street to the Eastern Promenade; Melbourne Street from Emerson Street to the Eastern Promenade; Montreal Street from Willis Street to the Eastern Promenade; and Walnut Street from Willis Street to the Eastern Promenade.

Munjoy Hill will be closed to all traffic at 4 p.m., with handicapped parking available on a first-come, first-served basis along Cutter Street and Fort Allen Park. Clearly marked handicapped vehicles will be allowed to pass the barricades until 6 p.m. and must approach Cutter Street from Fore Street to enter.

The Stars and Stripes Spectacular is privately funded, including support from Founding Partners of July 4th Portland – The Portland Press Herald/Maine Sunday Telegram, Quirk Chevrolet, Wright Express and the Maine Red Claws. Additional support for this year’s event was provided by the Time Warner Cable, Bangor Savings Bank and other corporate sponsors.