The Warning predicted at Garabandal is the same as the first secret of Medjugorje. The following long quote is from my book, The Secrets of Medjugorje and Garabandal Revealed:
“Everything will stop during the brief time needed for the Warning (minutes, not hours). Electronics and vehicles will not function, except in cases of necessity. People who are asleep will be awakened for this event.
“The Warning is entirely supernatural. Each person will find themselves alone in their mind and heart with their conscience. God will touch each person’s soul. God will enlighten each person’s conscience in a way which is fitting to the uniqueness of each individual, within the limits of each person’s knowledge and experiences. People will understand the sins and the negative consequences of their sins, but only in so far as any sin is on the conscience. The Warning illuminates the conscience, but does not provide any type of Divine Revelation. The knowledge that is obtained by the Warning about each person’s own sins is essentially the same type of knowledge that could have been obtained by a very thorough examination of conscience. So this event does not compete with Sacred Tradition or Sacred Scripture as a source of Divine Revelation.
“In an interview, Conchita gave a succinct and accurate description of this event:
“the Warning will be like a revelation of our sins — and it will be seen and experienced equally by believers and non-believers and people of any religion whatsoever…. The Warning will be a correction of the conscience of the world.”
“Every single human person on earth without exception will experience the Warning. Every single human person on earth will be offered grace and mercy directly from God. Even prenatals in the womb will be touched by God; though they have no personal sins to be brought to mind, they will be given blessings of grace to prepare them for the great difficulties of the world into which they will be born, especially the gift of God’s grace to strengthen them against sin (but they will not be sinless).
“For most persons, those who are old enough to understand right from wrong, the Warning will take the form of an awakening of the conscience, making that person aware of his current unrepentant sins and tendency toward sin. God will offer all sinners the gift of repentance and conversion from these sins, as well as grace and mercy more generally.
“For those who are holy and have few sins, and for those who have thoroughly repented from their sins and been forgiven, the experience will be different. For them, their sorrow will be at the sufferings of Jesus Christ on the Cross for the sins of mankind, much more than over their own sins. They will join with Jesus Christ in His loving sorrow for the sinfulness of the world.”
The Warning is one of many events described in the prophecies of Garabandal and Medjugorje. However, these events of the ten secrets of Medjugorje and of the Warning, Miracle, and Chastisement of Garabandal, all occur within the first part of the tribulation.
Subsequently, as Sacred Scripture indicates and various Saints taught, there is a long respite from the tribulation.
Only much later, a few hundred years later, does the tribulation resume with its second part. This second part of the tribulation includes the reign of the Antichrist, followed by the Second Coming of Jesus Christ and the establishment of a long era of peace and holiness on earth. And only after that long time of peace does the general Resurrection and general Judgment occur.