Well, it's in settings.txt, so you can easily see it and change it as you please. In Proportions it's at 3, but I may up it to 4 for Version 1.6.
I'm not sure if it really is "max", in the sense that, it will be a random value up to max, and sometimes less; or if it just is always that value. Same question for the damage level. I'd hope they'd be randomized, but I haven't tested it.
I suppose that in most games sensors III are discovered long before a SM ship is able to create storms...
Actually, right now, that component is quite useless, so I would mod the storm to allow for obscuration level 5 (which can only be defeated by destroying the storm).