Sorry it was not exactly this one that I have seen too of course. The other one in red letter in a red frame appeared when connecting to windy.com on a Mac.
But sure IT WAS a worldwide storm alert !
And it was on SPANISH.

Today at 20h30 (Chile hour) i open windy on my mac, but a strange message about an electric worldwide storm apear, this message say i should warning all people! Someone see that? Thanks for your information