Transmission started bucking between 45-65 mph if you stomp on it shifts and runs great ???

What is your question?

I'll be driving, when engine is cold or just started, driving at 60 the room will surge 250-500 RPM then so it warms up it stops. Today it was super cold and it started bucking

What makes this problem better or worse?

Warmer weather

How long has your 2007 Chevrolet Silverado 1500 had this problem?

Super cold today just started bucking today