Actually, it's just the Tulsa light pollution reflecting off the clouds. To the north is WalMart, Regal Plaza, Target, car dealerships....
...and billboards and 24-hour gas stations...
Metal Halide.
You are reaping the 'benefits' of lighting manufacturer's "white light" sales campaigns, to replace the orange-ish sodium lights with blue-rich Metal Halide and LED.
You notice it more because blue-rich light scatters in the atmosphere 4-5 times more than Sodium or incandescent light.
The new proposed Form Based Code contains provisions to limit blue-rich light like this, preferring instead light of a warmer nature (lower color temperature) and much less glare/scatter.
If you think that's a good idea, you can make your feelings known at the TMAPC Public Hearing Wednesday, February 2, 2011 in the City Council Chambers on the 2nd level of City Hall at 1:30pm.
It may be snowed out, but you can always send an email or call your councilor.
Why it matters:
http://www.illinoislighting.org/lightcolor.htmlhttp://docs.darksky.org/Nightscape/Article_SeeingBlue.pdf
