On Wednesday at 2:31 p.m. the NWS Wilmington NC issued a coastal flood advisory valid for Thursday between 4 a.m. and 8 a.m.

Like many across western North Carolina, Williams’ home was not in a FEMA-designated flood zone, so flood insurance wasn’t required, and she was unaware of the changing risks in recent decades.

Georgina Sanchez, a research associate at NC State’s Center for Geospatial Analytics, faults FEMA’s existing flood maps that show where people are required to buy flood insurance. She said ...