In this video, I discuss how cyclones are moving more slowly across the surface. This means that the storms can pick up more heat energy (since the sea surface temperatures or SST are warmer), and they can also pack stronger winds. The result is more powerful storms slamming into coastlines bringing more precipitation, higher force winds and devastation.
Note: At the time this video was recorded, hurricane Michael had just been upgraded to a category 4 storm. Obviously, it became much more powerful later on. In fact, Michael has been declared to be a more powerful hurricane than Katrina. Strengths is usually measured in millibars of pressure in the eye (not winds). The lower the pressure, the more powerful the storm (this typically indicates a tighter, smaller eye with a higher pressure gradient resulting in higher wind speeds rotating about the eye). Katrina was 920 mm; Michael, 919 mm.