The Pacific’s greater reach gives storms plenty of room to roam, but while they take advantage of that—especially in the tropics—they generally steer clear of North America’s west coast, going unnoticed by most people in the U.S. There are a number of reasons for that.

Human-caused climate change and El Niño have heated ocean waters to record levels, giving tropical storms a boost, scientists say For the first time on record, storms have reached top-tier Category 5 strength in every tropical ocean basin in the same year.