Yeah, could be that much around Houston, which is so flat (and so concrete-y) that any significant amount of rainfall can cause major flooding.
Several of the models have it stalling and lingering in one spot right over SE Texas, which is the real big rain threat. And some of those models also have it getting pushed back to sea, re-intensifying, and coming back in, either further east in Texas, or along the Louisiana coastline.
Can't say I've ever seen a storm quite like this one.