"Bye Northern Lights"

Yesterday Dad, Jenifer, Jenna, and I. We where all walking back to the house. Dad looked up at the sky and said, "Say good bye to the Northern Lights." I looked up and saw a green glow in the sky. "What's that?" I asked. "It's the reflection of the Northern Lights." answered Dad. Then we walked to the house. The reason Dad said "Say good bye to the Northern Lights." Is that the sky was getting cloudy so you can't see them.