It can mean to veer, or to go sour as applied to milk
Senior Project ... 
can go to protect the borders, one can serve the society, give one to the saints... [DOC] [TLE] turn | Definition, meaning & more | Collins Dictionary [PAR] turn | to move or cause to move around an axis | Definition, pronunciation, ... 15. 
to cause (milk, etc) to become rancid or sour or (of milk, etc) to become rancid ... 
17. to direct or apply or be directed or applied  he turned his attention to the ..... 
You can use turn to indicate that there is a change to a particular kind of weather.