My 2011 FLHTK ( ultra limited ) had the same left wheel howling in a sweeping curve or even an aggressive lane change and I read somewhere where others said it was the tire, So I had the shop put on a new Dunlop American Eliete with new wheel bearings but the noise is still present ( but it does have a differnt pitch ) changed out the brake pads to rule it out but the left turn howl is still there.

The only thing I noticed is that they did not re balance the front tire with new wheel weights ( the same old ones were simply left in the same spot ) not sure what difference this may make in reguards to the noise.

I really thought changing my front tire and bearings would solve this issue, but in my case it did not, Just saying...

 

Most likely your tires. I had the same problem. I thought something else was wrong. That was with 8k miles on my 19 GSG with factory Dunlops. Finally replaced the tires and it's gone.