Mick Mulvaney, the acting White House chief of staff, told Wilbur Ross, the commerce secretary, to have the National Oceanic and Atmospheric Administration publicly disavow the forecasters’ position that Alabama was not at risk, contradicting President Trump.

NOAA, which is part of the Commerce Department, issued an unsigned statement last Friday in response, saying that the Birmingham, Ala., office was wrong to dispute the president’s warning.