Really hoping for official answer. If a character with War Caster feat casts Booming Blade as a reaction to enemy provoking at 5' -> 10', is a reach weapon valid for the melee weapon attack component of the spell?
— Josh (@Gl33m1) April 11, 2018
Booming blade has a range of 5 feet, and its description says its weapon attack must be within that range. Whatever melee weapon you're using, the range is 5 feet. The spell really means it. #DnD https://t.co/4ad1qKYmM8
— Jeremy Crawford (@JeremyECrawford) April 11, 2018