How to tell if a Save The World mission will have a "major storm incoming"?

I recently started playing the Save the World campaign. I love exploring absolutely every single nook and cranny in the mission maps. I play solo, so it takes me a very long time to fully explore a map, but I just love doing it.

After the first few missions, I started getting warnings during a mission that a major storm is incoming which will end the mission within 2 in-game days.

At first, I was disappointed that I'd have to cease exploring and rush to finish the main objective. But now I'm very discouraged because it keeps happening. It seems every mission now has this storm time-limiter.

Do all missions from here on out have an incoming storm? If not, is there a way to tell if a mission will have one?

If I know the mission will have one, I can at least know to not waste time trying to loot everything in the map.

Every mission (other than storm shield defense) has a time limit, with some being longer than others (I believe the longest non-event limit is 4 days for a Protect 4 Atlases mission). This is to prevent people from afking in an instance of the game world forever. By using time limits, it also encourages players to work together to put together strong defenses quickly instead of solo-grinding resources and loot.

Fortnite is not meant to be a exploration game. While some discovery is necessary on each map (to find objectives, locate secondary targets, etc.), it is primarily a base defense FPS. Besides, once you've seen one map, you've seen pretty much all of them. They are all extremely similar.