More than likely the water pump is bad. The seal is going bad, when it's cold it will leak, as the motor warms up so does the seal, and the leak slows or stops. If you can get under the car, shine a light up on the bottom of the waterpump, there's a weep hole where the fluid usally leaks out. Sometimes on the V-6 engine the front motor case will corode and leak antifreeze also. Happy hunting