The next time you make a ranged weapon attack during the spell’s duration, the weapon’s ammunition, or the weapon itself if it’s a thrown weapon, transforms into a bolt of lightning. Make the attack roll as normal. The target takes 4d8 lightning damage on a hit, or half as much damage on a miss, instead of the weapon’s normal damage.
Whether you hit or miss, each creature within 10 feet of the target must make a Dexterity saving throw. Each of these creatures takes 2d8 lightning damage on a failed save, or half as much damage on a successful one. The piece of ammunition or weapon then returns to its normal form.
At Higher Levels.
When you cast this spell using a spell slot of 4th level or higher, the damage for both effects of the spell increases by 1d8 for each slot level above 3rd.