i believe animals can sense the weather change.
i also believe the animals are out all the time, but graze like a farmer plows...
bow hunting one year, i noticed that the deer would be over in an area, so i would go over there, and the next day they be a lil further..so i moved..and so on..
then it was like they started over...so i had 3 days left...so i didnt go to where i thought they would be in the mornin, i went and set up at the spot i thought they would be at in 2 days....sure enough..mornin came, still out of range..but went right through the area i had thought they might go to...the next mornin..whamo...taxed that azz...was a lil deer... but still the pattern paid off...
maybe put a cam up there and see when they roll back through.