Take a slice of lemon and rub it over the winter-roughened spots. Leave it there for five minutes, and then rinse it off with cold water. Do this every morning until the dry area is soft again. After just one treatment, the ashy skin will start to flake off because the acid in the lemon will help loosen dead skin cells. This is great for knees and feet as well, and will even lighten dark spots. So obviously this is wonderful for big events where a little skin will be shown, or just in time to take care of those dark ashy problem areas before wearing shorts and bathing suits when the weather gets warmer.
Lastly, just be cautious not to get the lemon on clothing. Lemon juice has acetic acid in it and acts like a bleaching agent, especially when it's exposed to light. So if you get some on your clothes, no worries. It won't bleach them right away, but wash it off as soon as possible.
Cheers and here's to happy, healthy living.