The phrase "a formal alert" is correct and usable in written English.
It can be used in contexts where you need to notify someone about an important issue or event in a professional or official manner.
Example: "The company issued a formal alert regarding the upcoming changes in policy that will take effect next month."
Alternatives: "an official notification" or "a formal notice."
A formal alert system allows serious declines to be identified and brought to the attention not only of conservationists and those responsible for countryside policy but also the general public.
The US Federal Bureau of Investigation FBII) has issued a formal alert telling airlines to be on the lookout for hackers.
Following the initial unrest and alert level raise, the official meteorological and volcanological hazard monitoring agency for Cape Verde (National Institute of Meteorology and Geophysics: INMG) issued a formal alert of impending eruption to the Civil Protection on 17 October.
But Public Health England is sufficiently concerned that, on Thursday, it issued a formal alert warning drug users to beware of deals sold as heroin that could contain fentanyl and carfentanyl.
But to see a comprehensive and formal alert by the presidential panel makes one feel doomed.
S. Shyam Sunder, the leader of the investigation, cautioned that it was too soon to know if a formal bulletin or alert would be issued.
Facebook officials have agreed to take down some unofficial tribute pages for victims of the Sandy Hook Elementary School shooting after Connecticut lawmakers submitted a formal letter on Monday alerting the social media giant to the pages' exploitive nature.
It did not send out a formal, take-note-of-this alert.
But this was by way of an e-mail, rather than a formal take-note-of-this alert.
Publishing a formal correction does more than alert readers of that day's paper to an error.
The GMC had been alerted by a formal complaint from a member of the public early in 2005 to yet another case of potential misconduct by Patel, sparking wider investigations into the pathologist's performance.
