Let thunder duration vary by biome

A lot of people don't know this, but for those of us who live inland and in hilly country, the noise level and reverberation of a thunderclap will go on, and on, and on. People who live in very flat areas or near the ocean don't really experience this; my wife from California USA was very shocked when she started living in the Southern US, because thunder rolls and rolls in that region, sometimes lasting we'll over three to five seconds per lightning strike. Even cloud-to-cloud strikes can cause this. Long thunder should be the norm in warm biomes wherever there is no rainfall, as compensation, and should also happen in mountainous biomes because of the echo we would expect in real life.