2002 Ford Taurus AC blowing hot and smoking

I'll be driving down the HWY doing about 65mph and the AC will start blowing hot and when i come to a stop smoke starts pouring out from under the hood. As soon as the smoke stops the AC blows cold again. Its not running hot the gauge says its normal temp. and the smell coming from the engine isn't antifreeze. I would donate some money to you guys but i spent all my money on just getting this car and already having troubles with. Please help very puzzled.