Late summer bottom deep mostly empty
First you’re a beekeeper I’ve had incredible activity in the hive, done weekly checks things have looked good. I hadn’t checked the bottom deep for a month, when I did today it was mostly completely empty of either brood or honey or pollen. The second deep above the bottom deep is full to the brim of brood and honey. There is a medium super on top that is about 60% full of honey.
Is this part of the winter preparation or are we in trouble?