The release of the NOAA statement provoked complaints that the Trump administration was improperly intruding in the professional weather forecasting system to rationalize an inaccurate presidential assertion. In opening its investigation, the Commerce Department’s inspector general said the events could call into question scientific independence.

The House Committee on Science, Space and Technology expressed similar concerns as it announced its own investigation into Mr. Ross’s actions on Wednesday.

“We are deeply disturbed by the politicization of NOAA’s weather forecast activities for the purpose of supporting incorrect statements by the president,” wrote Representative Eddie Bernice Johnson, the chairwoman of the committee, along with Representative Mikie Sherrill, the chairman of its oversight panel.

The latest challenge to Mr. Trump’s credibility has its origins in one of the more prosaic duties a president has: warning the nation when natural disasters like Hurricane Dorian threaten communities.

On Sept. 1, as Dorian gathered strength over the Atlantic and headed toward the East Coast, the president wrote on Twitter that Alabama, among other states, “will most likely be hit (much) harder than anticipated.” Earlier forecast maps had suggested that Alabama might see some effects from the edge of the storm, but by the time of the president’s tweet, the predictions had already changed.

A few minutes after Mr. Trump’s tweet, the National Weather Service in Birmingham posted its own message on Twitter flatly declaring that “Alabama will NOT see any impacts from #Dorian. We repeat, no impacts from Hurricane #Dorian will be felt across Alabama.” The forecasters were correct; Alabama was not struck by the hurricane.

Nonetheless, Mr. Trump was furious at being challenged and kept insisting for days that he had been right. He displayed or posted outdated maps, including one that had been apparently altered with a Sharpie pen to make it look like Alabama might still be in the path of the storm. He had his homeland security adviser release a statement backing him up.