Recently upon joining my Tekkit Lite server I've been hearing these large rumbling sounds like you'd get during a thunderstorm, however when I actually spawn in the world it's a nice calm day with no rain or lightning in sight.
Additionally I noticed it had also caused the outbreak of a number of fires which is quite annoying as it sets a number of trees on fire which then quickly spreads across the entire forested region that I'm situated by.
What could be causing these mysterious thunderstorm sounds and fires? - It would be nice to get to the bottom as this has happened twice now.
Another note: This problem has also been experienced by other players on the server however I myself have yet to actually play in a thunderstorm. Also another point is that this doesn't seem to occur every time I join, just a few.