What does the blinking yellow arrow on the traffic light mean?

It means that you may make the indicated turn on a permissive basis, after yielding to conflicting vehicles and pedestrians. It also means you may be taking your life and others into your hands assuming the driver of on-coming traffic knows what a blinking yellow light really means. It's like playing Russian Roulette but only with a blinking yellow light.

State officials say this is usually the same as turning on the circular green, but the flashing yellow arrow can be displayed at times when the straight ahead movement can not be given a green light. Aaaa, excuse me. You're saying the flashing yellow can do things a green light can't?  What was wrong with the "Cautious Left Turn on Green?"  Doesn't that mean the same thing as the blinking yellow? Sorry, but I'm just using some common sense here.

The purpose is to eliminate a dangerous condition called yellow trap. It occurs when the circular green is used to allow permissive turns, and one circular green ends sooner than the oncoming circular green. The left turning driver receiving the earlier yellow light tries to turn across traffic that still has a green light, causing an accident. The flashing yellow arrow can keep flashing until the oncoming green gets a yellow, allowing the driver to turn safely or to plow into the car making the turn and telling the driver later he had the right away.