I have never used addWeatherEffect, but I have spawned lightining using a different line.
instead try:
EntityLightningBolt lightning = new EntityLightningBolt(world, x, y+1, z);
world.spawnEntityInWorld(lightning);
As for the explosions:
world.createExplosion(lightning, lightning.posX, lightning.posY, lightning.posZ, <Explosion Strength, Go With A # Around 4>, false);