What usually develops along a front where cold air meets warm air?

Honestly "global warming" may be a slight possiblity, however they called it "climate change" because its not real, in fact we had one of our coldest days here not too long ago, and the "issues" with this subject is a blindfold for actual problems.

Inner peace.. jk it's  a stable electron configuration

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other

34 degrees fahrenheit