Some may ask if a tropical cyclone can form while inland. The answer is not as straight forward as it can seem. Warm-core lows do form over land frequently, but something very close to 100% of these would never be considered tropical cyclone-like. But there are exceptions.

In this situation, both ground and deep layers of the atmosphere are very saturated. Given favorable upper-level support, Invest 90L could, in theory, pull something off even prior to moving offshore (assuming it does move offshore). Definitely interesting to watch, and very dangerous, regardless. There is genuine potential that if 90L does get named (which would be Arthur), this ongoing flooding could be so significant that it ends up being considered for retirement.