Lemon Cloud Jell-O Mold

1 (6 ounce) box lemon Jell-O
3 cups boiling water
1 (6 ounce) can frozen lemonade
1 (8 ounce) carton Cool Whip

Dissolve Jell-o in boiling water and add lemonade. Refrigerate until jelly-like. Fold in Cool Whip and pour into a 6-cup mold.
Refrigerate until ready to unmold and serve.