Here's some more info about the changes:
https://www.fema.gov/flood-insurance/risk-ratingHouston, Austin, and San Antonio will get hit hard with the "increased rainfall" metric. Those cities have the highest density of rainfall gauges, measure the most data, and had huge relative jumps in annual rainfall the last time the data was updated a few years ago. NOAA won't admit that they punished cities for building robust flood warning systems, but they used all that data to change 12" of rain to 16" of rain that was influenced by recent storms while lessening the more historical and better distributed rainfall data.
Houston and the Gulf Coast will get hit hard because they're flat. FEMA rates now take into account elevation above the floodplain. With Houston being very flat, most houses are within a foot or two of the 100-year flooding elevation. If you are closer in elevation to the floodplain, you pay more. This neglects the fact that flat areas also store more water than hilly areas. So a house could be 1' above 100-year in Houston, but require going from 12" of rain to 24" of rain to fill the entire floodplain 1-foot higher. A house in Austin on a creek slope can be 1' higher than the floodplain and require going from 12" to 13" of rain to flood. Both would be treated the same in terms of elevation.
Houston will get hit hard by the "equity" part of the revision. People in Houston actually care about flooding. They will ask if a house has flooded before and they will pay less if it does. People in other cities don't usually ask or care that much. FEMA rightfully says that low-value houses flood more than high-value houses and end up paying more after a flood event (because cheaper houses flood, so people pay less for them, so the houses that flood are cheaper...you get the idea). Unfortunately, making smart decisions like buying a house with a lower risk of flooding gets punished by the Feds. So people with higher home values will subsidize low-value property flood insurance.
SE Houston and coastal areas get hit hard because of coastal issues. It's a concept called "combined probability." Not gonna explain it here because I've already written too much. Google it if you want to learn more.
Let me guess, OP, you live in a house in Houston, close to the 100-year floodplain but not in it, and your appraisal is at least $300k, right? Might also live in Galveston County or SE Harris County.
A lot of people need to seriously consider dropping their flood insurance with the increases that are coming. Make your own decisions, but I'd drop it if I have a townhome with a kitchen on the 2nd floor, a first-floor kitchen I wouldn't mind remodeling, 1st floor bathroom I wouldn't mine remodeling, or only half-baths on the first floor.