the arrival is also related to that 1thessalonians 4 :
15. For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord, will not precede those who have fallen asleep.16. For the Lord Himself will descend from heaven with a shout, with the voice of the archangel and with the trumpet of God, and the dead in Christ will rise first.17. Then we who are alive and remain will becaught up together with them in the clouds to meet the Lord in the air, and so we shall always be with the Lord.
the arrival is prepared in many ways ... but for those alive at this point it should be something happening very quick.