First of all let me say I love the idea of a Gigantix spawning in a storm and roaming around in a violent rage until strong players band together to bring it down. Awesome idea. However, the execution was very poor. There are tons of things that can be done to make this system better, but I'm only going to focus on 1: a heads-up system.
Urgent Quests give a 15 minute heads-up for players to prepare, followed by a 30 minute window to defeat the boss in. Operatives will warn when a Trial is about to start and when it does, it is clearly marked on the map so any player in that area can see it and participate if they wish. These types of systems currently in the game help players to prepare for and adapt to situations as they come, and they are great systems. Unfortunately, the Gigantix does not have these.
Storms come at random intervals with absolutely no warning beforehand. From a lore-perspective, it doesn't make sense for Operatives not to warn their agents out in the field that a super powerful dangerous monster is about to spawn and kill them, nor does it make sense for there not to be any kind of weather forecast or alerts in a world where technology far surpasses our own. From a gameplay perspective, it's not fun to have to sit around and wait for a Gigantix to spawn and not get to enjoy the rest of the game. And yes, I mean HAVE to, because if you are doing anything besides waiting for it, even something as simple as gathering on the border of the area you are in, the boss could spawn and you will lose half its duration just trying to reach it in time.
At the very least, there should be a meteorologist NPC that players can talk to in town to get a forecast, but personally I think it needs to go a step further. I think we need a warning system, just like we have for Trials and Urgent Quests. An operative should come on our screen a few minutes before a storm is coming and give us a heads-up. They could say something like, "It looks like a big storm is coming, be careful out there!" That would allow players out in the field going about their business to start heading over to the area where the Gigantix is known to appear and prepare for its arrival. Meaning that players can actually play the game normally and get to enjoy the Gigantix system, versus what it is now which is sit around waiting and hope you don't need to use the restroom or you could miss it.
TLDR: We should get a warning when a Gigantix (bad weather) is coming, the same way we get warnings for Trials and Urgent Quests.