Rain and thunderstorms could put a damper on a massive military parade on President Donald Trump's birthday in the nation's capital and hundreds of protests around the country planned for Saturday, forecasters said.

Much of the central and eastern parts of the country will experience showers on Friday and through the weekend, with the greatest risk for rain and thunderstorms in southeast Texas, the Mid-South and portions of Virginia, the National Weather Service said. A large area spanning from Chicago to Washington, D.C. will be covered by a slow-moving system expected to bring daily showers and storms.

The storms are in time for the planned parade in D.C. celebrating the 250th anniversary of the U.S. Army, also falling on Trump's 79th birthday. The parade costs $40 million and will feature tanks and troops rolling through downtown with Trump looking on from a specially built reviewing stand.

The same day, protests are planned in 1,800 communities in all 50 states are expected to be the largest and most numerous anti-Trump demonstrations since he took office in his second term. The so-called "No Kings Day" protests will center with the largest in Philadelphia, where forecasters said Saturday will look "cloudy, showery, drizzly, and humid."