Well, according to the very Word's of the Lord the 'parousia' occurrs the great tribulation:
"Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken:And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory."
Jesus warned of false prophet and false teacher who would be teaching of ANOTHER coming prior to this coming that HE taught us:
"For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect. Behold, I have told you before. Wherefore if they shall say unto you, Behold, he is in the desert; go not forth: behold, he is in the secret chambers; believe it not. For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming (parousia) of the Son of man be."
The context of these warnings by our Lord is both during and after "
the tribulation of those days" i.e, "
great tribulation".