Pre-detect can't working properly in the end of thunder & rain.

[Rivmun]

Due to the return value of Minecraft function. It's hard to determine what is the next weather when thunder & rain is over.
Now this mod is considering next thunder is rain, and next rain is clear. Density change is also based on this.

Detail: MinecraftClient.getInstance().getServer().getWorld().getProperties().getWeatherClearTime() is always return 0 in normal play-through without use command.