I'm applying to grad schools, and my fall semester grades will be out before the deadline. I know my GPA is going to fall, so I'm thinking of submitting my applications without those grades. Is it acceptable to submit my application when the grades aren't out yet, even though they will be out before the deadline for the application or when the deadlines are in January, that means they expect to see the grades for the Fall semester? (They'll be out in a few days actually.)
You certainly can do so—many students must, given that the deadline at many schools is before the fall semester is complete.
However, note that any school that accepts you will want to see your finished transcript before allowing you to enroll. Significant plummets in grade (going from an A average to a C average in your final year, for instance) will raise eyebrows, and potentially cause some schools to withdraw offers.