I think St. Faustina made references to "The Warning" (but not in those words) in her writings too. I'm not sure where the "Three Days of Darkness" prophecy originated. I do know that Garabandal, which mentions both, is not said to be authentic by the Church.
Please post whatever you find associated with St. Pio and these subjects, OK?
BTW, please keep me informed also. I do not want to post any misinformation but I want to cover all bases!
Disregard the Padre Pio reference!
See this website.
http://www.acad.sunytccc.edu/clubs/basic/rosaryqueen/PadrePio/default.htm