94 Taurus 3.8 cold start clunk sound

Hello
I notice a single "clunk" when starting in cold weather. It's below freezing here too. Turn key, starts to crank just a little, "clunk" 1 time, then continues to crank until the engine starts. It's below freezing here also. New battery 6 weeks ago. Subsequent attemps at starting and no clunk sound during starting. After engine warms up it seems OK.

Any thoughts?? Starter going out??? Relay going out for a split second??

Thanks

B