Disasters Not Happening?

It's really got me stumped

I've been working on a plugin recently that attempts to make the Nova economy more realistic, along with some other goals but this is what I've decided to fix first. One big thing I've come across in the process is that disasters do not appear to be happening at all!

I've removed all my plugins and started a new game, but even still after a while of playing there are no disasters listed in the pilotlog.txt file.

In order for them to show up, does the player actually have to visit the planet in question? I've tried making disasters with 100% odds of occurring but still they don't. Is there some global probability of disasters occurring on top of the one entered? I suppose one thing I'm not quite clear on is exactly what it means for a disaster with say a 30% chance of occurring actually means, since for example if said disaster lasted for 30 days it would seem like it would almost always be tripped if the probability was a chance each day of starting.

I'm currently running 1.1.1 on a 2011 Macbook Pro if that helps anyone in figuring out what's going on.

Any insight or observations you've had would be great, if you've had a similar problem or know anything about it, or if you can give a better explanation of how the probabilities work in regards to disasters.

Thanks for taking the time to read this and for any help you might be able to offer.