The situation is that a strange light is pouring out of somewhere, and I'm not quite sure how to describe it. If you look at this animated image (Might take a while to load): Ignore the explosion at the start, but after that - the way the light moves. That's what I'm trying to get at, but I'm struggling to portray it very well. How would you go about it? Thanks.
A coruscating radiance blazed forth from the source, shifting and writhing like a mad aurora borealis. Glowing tendrils formed, twisted, and dissipated...
...and the light choreographed its brilliance, and it swayed and entwined and embraced itself presenting a luminous dance, a secret weave of dance, to a melody only it could understand.
"A screaming comes across the sky." (That hasn't been done before, has it? ) I do offer the serious suggestion that perhaps less literal description might be what you're after--Gravity's Rainbow's first sentence describing the effect of V2 rockets (the source of the above quote) works for just that reason.
Suddenly, the clear night sky ebbed and flowed with phosphorescent amber, soaked the the diamantine stars in its diaphanous glory--then dissipated and was gone.
The amber light radiated with slow-flowing magnificance. The halo and it's shimmering dance flowed farther and farther into the sky.
I can't remember what I had to start with, I rubbed it out several times. Was just something about the light twisting and dancing as it poured out into the night sky, or something along those lines.
I'm not being mean at all. This is a writing site, and in te end it doesn't matter haow anyone else would describe a particular image. Several members gave their own take on it, but it still is up to NM to come up with the description that would work for him, and that reflects his own writing style.