I wouldn't agree with this timeline. Please consider:
Gen 6:7-9 The LORD said, "I will blot out man whom I have created from the face of the land, from man to animals to creeping things and to birds of the sky; for I am sorry that I have made them." But Noah found favor in the eyes of the LORD. These are the records of the generations of Noah. Noah was a righteous man, blameless in his time; Noah walked with God.
Noah was "right with God" (righteous) BEFORE the ark was even discussed. It even says "Noah walked with God" much like Enoch.
I liken Noah to Abraham. Abraham simply believed God and it was credited to him as righteousness (Rom 4:3) but he was also justified by his works but much later (James 2:21).
Amen!
I'm pinging you to the post above in answer to your question. Noah wasn't saved by anything HE did. The scriptures clearly says "Noah found favor in the eyes of the LORD". It's clearly not anything Noah did to earn the Lord's favor otherwise we would have to conclude Noah earned his salvation which he did not. Why Noah found favor in the eyes of the Lord is not defined in scripture but it is clear the Lord had mercy and grace to Noah.