Thunderous smites

For the spells duration you imbue a meelee weapon in your hands with the raw power of storms. 

The first time you hit with a melee weapon attack during this spell's duration, your weapon rings with thunder that is audible within 300 feet of you, and the attack deals an extra 2d6 thunder damage to the target. Additionally, if the target is a creature, it must succeed on a Strength saving throw or be pushed 10 feet away from you and knocked prone.

At higher levels: When you cast this spell using a spell slot of 2nd levei ar higher, you deal 1d6 thunder damage on a number consecutive hits made with this weapon equal to every slot level above 1st.