Our Lady kept her appointment and appeared on August 13, but the children were in jail...
Witnesses at the Cova, heard the thunder, and saw the lightning at the appointed time. They also perceived a small white cloud above the holm oak, and noticed an unusual coloration reflected upon the faces of those present, on their clothes, the surrounding foliage, and so on. The phenomenon did not last long - yet curiously, it seemed to foreshadow aspects of the miracle of October 13, that all would witness.
I found that interesting as regards the apparitions of Medjugorje - where it is claimed Our Lady appears wherever the seers are, not necessarily where she expects them to be. However, on the last apparition to Bernadette at the Gave, Our Lady appeared in the niche as usual, though a fence had been erected and the seer could only approach as closely as across the river. Thus the Blessed Virgin didn't relocate to convenience the little saint.
My Medjugorje distinction may be trashed however, considering that Our Lady did appear to the Fatima children in another location - on this date in 1917 to be exact. She met them at an uncle's farm at Valinhos on August 19, around 4 o'clock in the afternoon... It was in that 'unplanned' apparition Our Lady promised the miracle of October 13. She also asked for a procession in honor of Our Lady of the Rosary and donations for a chapel to be built. Our Lady promised to cure only some of the people Lucia prayed for. This is consoling to consider, because not all prayers for healing are answered. Our sufferings may be necessary for our salvation... they may be our cross, and therefore already a favor from God.
It was also in this apparition that Our Lady appeared sad and made this plea:
‘Pray, pray much, and make sacrifice for sinners, for many souls go to hell because there is no one to sacrifice and pray for them.’ OL Fatima, August 19, 1917, Valinhos