Rain is not the problem. Thunderstorms are typically associated with localized (1/4 mile) cells of intense rain, but the updrafts, downdrafts, and wind shear that are dangerous to even huge aircraft are widespread (pilots are taught to avoid the cells by 20+ miles).
Hence "no rain" at your relatives' homes is not inconsistent with NOTAMS (Notices to Airmen) to avoid dangerous weather. I just looked at weather radar for DFW and it looked like there was a possible squall line forming near enough to be a problem.
I do not discard the possibility that the radar reports are faked.