By Terry Eliasen, Meteorologist, WBZ-TV Exec. Weather Producer

BOSTON (CBS) – If you look up Tuesday there is a good chance you may see a halo in the sky!

Halos around the Sun and Moon are certainly not rare. They are caused by high cirrus clouds refracting light.

Cirrus clouds are so high in the sky (typically higher than 20,000 feet), they are made up of millions upon millions of tiny ice crystals which readily refract the light from the Sun or Moon.

Perhaps the coolest thing about halos (or rainbows too for that matter) is each one is different. In other words, the halo that I see is sort of my own personal halo, different even from a friend or neighbor standing right next to me. We each see the crystals slightly differently depending upon our position, so no two halos are exactly alike!

Often halos can be a sign of bad weather ahead (rain or snow) because the high cirrus clouds are typically the first to arrive before a storm and that is exactly the case Tuesday. These clouds are streaming out ahead of a frontal boundary which will eventually bring rain to parts of our area later Wednesday and Thursday.

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