The possible nomination of Louis A. Tambs as US ambassador to Panama is provoking very disfavorable reaction in the Panamanian press.
Monitor Latin America correspondent James Nelson Goodsell writes that La Estrella de Panama, the major morning daily here, said Mr. Tambs' nomination would be ''not only inconceivable, but also a grave impudence'' on the part of the United States.
Mr. Tambs, a professor of history at the University of Arizona, was an ardent opponent of the Panama Canal Treaties under which the US is turning over the canal and adjacent territory to Panama in stages by the end of the century.
There were reports over the weekend that the Reagan administration might withdraw Mr. Tambs' name, but this has not been confirmed here.
Mr. Tambs, if nominated and confirmed by Congress, would replace Ambler H. Moss Jr., who has been ambassador since 1978. Mr. Moss is widely respected in Panama and has played a major role in orchestrating closer ties between the US and Panama. This past week, the English-language Star and Herald said Mr. Moss is ''uniquely tailored to the post-treaty atmosphere'' in Panama, and US-Panama relations are ''at an all-time high,'' due largely to his efforts.