In a letter released Tuesday, NOAA's acting chief scientist Craig McLean condemned an unsigned NOAA statement from last Friday that supported President Trump's incorrect claim that Hurricane Dorian would threaten Alabama.

The big picture: McLean said that NOAA's "intervention to contradict" the Birmingham office's assertion that Dorian would not impact Alabama "was not based on science" and was "simply put, political." On Monday, the New York Times reported that Commerce Secretary Wilbur Ross threatened to fire top NOAA officials for contradicting Trump. McLean plans to investigate if the agency's statement violated its policies and ethics.

Read the full letter:

Dear Colleagues,

The fierce storm we know as Hurricane Dorian has concluded its ferocious path through the Bahamas and along the U.S. East Coast. Many of you have contributed to the excellent science that has underpinned the forecasts and current understanding of storms such as this one, which accelerated quite rapidly in intensity. The storm also presented challenges in track which improved with enhanced observations. We know that our collective work, from the scientists in the aircraft penetrating the storm, to the scientists deploying the glider picket line, to the modelers and folks working the physics of the storms, across OAR and in our CI'S, and across all NOAA Lines, we are working the problem in order to give the NWS forecasters the best tools we possibly can to keep America and our neighbors safe. Thank you.

During the course of the storm, as I am sure you are aware, there were routine and exceptional expert forecasts, the best possible, issued by the NWS Forecasters. These are remarkable colleagues of ours, who receive our products, use them well, and provide the benefit of their own experience in announcing accurate forecasts accompanied by the distinction of all credible scientists—they sign their work. As I'm sure you also know, there was a complex issue involving the President commenting on the path of the hurricane. The NWS Forecaster(s) corrected any public misunderstanding in an expert and timely way, as they should. There followed, last Friday, an unsigned press release from "NOAA" that inappropriately and incorrectly contradicted the NWS forecaster. My understanding is that this intervention to contradict the forecaster was not based on science but on external factors including reputation and appearance, or simply put, political. Our NOAA Scientific Integrity Policy and Code of Scientific Conduct make clear that all NOAA employees shall approach all scientific activities with honesty, objectively, and completely, without allegiance to individuals, organizations, or ideology. The content of this press release is very concerning as it compromises the ability of NOAA to convey life-saving information necessary to avoid substantial and specific danger to public health and safety. If the public cannot trust our information, or we debase our forecaster's warnings and products, that specific danger arises.

You know that the value of our science is in the complexity of our understanding, our ability to convey that understanding to a wide audience of users of this information, and to establish and sustain the public trust in the truth and legitimacy of that information. Unfortunately, the press release of last Friday violated this trust and violated NOAA's policies of scientific integrity. In my role as Assistant Administrator for Research, and as I continue to administratively serve as Acting Chief Scientist, I am pursuing the potential violations of our NOAA Administrative Order on Scientific Integrity. Thankfully, we have such policies that are independently cited as among the best in the federal community, if not the best. Your NOAA and OAR management and leadership team believes in these policies and principles. I have a responsibility to pursue these truths. I will.

Thank you for your continued excellent work, and your trust. Carry on.

Go deeper: Wilbur Ross threatened NOAA firings after Trump hurricane contradiction