Weather Instantly Changing

Noticed a small glitch where the sky was clear and then instant fog.  I have the weather set to randomly choose in the TimedExecute plugin every 2 hours (plenty of time).  No other weather plugins or weather-related timers.

what was the weather pattern? can you send a clip?

Like a video?  I wasn't recording the screen, so no.  It was very clear and then went instant fog.

what was the weather pattern? can you recreate the bug?