Rashi on Genesis
בראשׂון IN THE FIRST MONTH — According to R. Eliezer this would be Tishri, and according to R. Joshua Nisan (Rosh Hashanah 11b).
Sforno on Genesis
ויסר נח את מכסה התבה, he had thought that the earth had already dried out completely only to find
Radak on Genesis
[Began] to dry. It was still like mud, dry on the surface but soft underneath. Noach knew that Hashem would tell them when it was safe to go out.