
Today the sky looked weird to me, I drove over to Lompoc to do a (rare) day shift and the sky was overcast with heavy fog, so typical here on along the Pacific coastline. At lunchtime I could only see a little bit of blue here and there....but it looked weird, I wondered if we were going to get rain.
I have just finished watching our local weather report and there was apparently a fire rainbow sighted over the Lompoc/Vandenburg area, with some heavy rain and hail up in the mountains. A fire rainbow is an optical phenomenon and rarely seen, and conditions for viewing have to be perfect. In order to be observed, the sun must be very high in the sky, at an elevation of 57.8� (90 -32.2�) or more, and can only occur in the presence of cirrus clouds.
The arc is formed as light rays enter the horizontally-oriented flat hexagon crystals through a vertical side face and exit through the horizontal bottom face. It is the 90� inclination that produces the well-separated rainbow-like colours and, if the crystal alignment is just right, makes the entire cirrus cloud appear to shine like an undulating rainbow.
The scientists call it a circumhorizontal arc ..but I think Fire Rainbow has all the appropriate drama phenomenon deserves

Pictures and info courtesy of Wikipedia