ForceWeather
Syntax:
ForceWeather WeatherID WeatherOverrideFlag (optional)
Example:
ForceWeather Clear ForceWeather SkyrimStormSkyrim 1 fw SigilWhiteOut
Forces the weather to immediately switch to the specified weather. If OverrideWeatherFlag is 1, the weather will not change again until ReleaseWeatherOverride is called. Otherwise, the weather will change back in the normal fashion according to the weather system.