This mod adds some compatibility between TerraFirmaCraft and Weather2. For example, snowstorms can now spawn when the current temperature is at or below -2°C, and sandstorms can spawn when rainfall is at or below 100. This means the type of weather won't always be "rain".
The upper and lower limit rainfall for where sandstorms can spawn is configurable, and ditto is the temperature requirement for snowstorms. Default is what was mentioned before.