Roman, on many occasions a UTA will appear as a straight bar or obvious enhancement at the very top of the 22 degree halo. The 'wings' form when the Sun is at the correct altitude above the horizon and look very dramatic. If you mentally chop the wings off the sample image until you are left with a straight bar, this will match up well with John's image. Hope this helps, and I hope you catch one soon!
As I have noted for many years, they appear more often in winter (early spring), when there are sometimes several days with alot of Ci/Cs.
Well, I do not remember any sun halo in summer.
