The workers, whose pay is being withheld during the ongoing shutdown of the federal government, concealed the message as the first letter in each of 11 lines of a forecast discussion for south-central and southeast Alaska Friday, The Washington Post reported Monday.
The service simultaneously published a version of the discussion without the hidden message.
The National Weather Service excepted about 3,935 employees from the shutdown.
"There's no money to pay them," Dan Sobien, president of the National Weather Service Employees Organization, said in an interview with Popular Science. "Nobody knows when anyone's going to get paid."