I believe Matthew's chronological sequence to be accurate. First "the great tribulation," then the Second Coming:
21 For then there will be great tribulation, such as has not been from the beginning of the world until now, no, and never will be.
22 And if those days had not been cut short, no human being would be saved. But for the sake of the elect those days will be cut short. (Matt. 24:21-22 ESV)
Nothing to do with the siege of Jerusalem:
29 "Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light, and the stars will fall from heaven, and the powers of the heavens will be shaken.
30 Then will appear in heaven the sign of the Son of Man, and then all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of heaven with power and great glory.
31 And he will send out his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of heaven to the other.
32 "From the fig tree learn its lesson: as soon as its branch becomes tender and puts out its leaves, you know that summer is near. (Matt. 24:29-32 ESV)
Note the parable of the fig tree. The great tribulation will be accompanied by many signs:
30 "And I will show wonders in the heavens and on the earth, blood and fire and columns of smoke.
31 The sun shall be turned to darkness, and the moon to blood, before the great and awesome day of the LORD comes. (Joel 2:30-31 ESV)
This is confirmed by Revelation:
12 When he opened the sixth seal, I looked, and behold, there was a great earthquake, and the sun became black as sackcloth, the full moon became like blood,
13 and the stars of the sky fell to the earth as the fig tree sheds its winter fruit when shaken by a gale.
14 The sky vanished like a scroll that is being rolled up, and every mountain and island was removed from its place. (Rev. 6:12-14 ESV)