The ring is caused by the bending of light rays through ice crystal clouds. Those type of thin high clouds often precede a weather front, so expect rain in a day or two after you see the ring. Those are called lenticular clouds and often foretell rain or snow within a day or two. They are a reflection of the mountain forcing the air to reveal moisture high in the atmosphere. That invisible moisture often comes before a weather front.
Snow avalanches kill more people in the mountains than any other natural disaster.
You can reduce your risk by understanding avalanches, but remember, even experienced back country mountaineers are killed by slides. Sometimes for the better, but often for the worse. Especially dangerous are sudden rises in temperatures. Increasing temperatures, especially with rain on top of new snow - generally mean hazardous avalanche conditions. Cooler temperature may improve snowpack stability, but always beware.