Throwing advic?

I am from texas but i am playing baseball in minnesota. I do really good in the fall and then when winter hits i lose my arm strength because we cant get outside and throw any more and we are confined to throwing the length of the gym. Is there any advice on how i can keep my arm strength up in the winter to be prepared for spring?

Throw every day. Even if just fifteen or twenty minutes at a time, even if you’re stuck with throwing indoors, throw every day, just to keep the arm loose and flexible. And a couple of times a week, get a catcher and do a bullpen session during which you can focus on some aspect of your mechanics or work on a new pitch or refine an existing one—and if you can get a portable mound, set it up at 60’6", have your catcher assume his position behind the plate, and work on control, location, whatever. I used to do this when I was living in New York and it was too cold to do anything outdoors in the winter. 8)