it's about to dump an incredible volume of rain all over the Carolinas. Flooding is probably the biggest concern. And the slower it moves, the worse off people will be.

I cannot even imagine 40 inches of rain.

By far, the most serious threat from a tropical cyclone to Texas residents is flooding.
And the worst thing about it is that the weaker the system is, the more efficient it is at producing heavy rains and catastrophic flooding. Claudette (1979), Allison (both 2001 and 1989), and Charley (1998) stand out as recent examples of this fact. Amelia (1978) showed that a system can meander around the state for over a week , creating a headache for residents anywhere between the High Plains and Coastal Plain. This proves the point that any system, no matter what strength, can create major problems for Texas.

https://www.weather.gov/media/lch/events/txhurricanehistory.pdf

that could increase it's intensity.

The fact that storms tend to weaken as they move over relatively cooler water, then dissipate once over land is consistent with what we're witnessing with hurricane Florence.

Track the storms atmospheric pressure, which has gone up from 943mb yesterday to 955mb today. That's still very low and consistent for a hurricane type phenomenon. That pressure should continue to rise as the storm makes landfall and its source of warm ocean moisture is cut off.

I would not expect the hurricane's wind speeds to increase as it ventures closer towards the coast and inland.