The storm struck Tuesday at about 4 p.m., and it wasn't long before about a metre of water collected in the area of the Oak Hills trailer park.
Initial reports suggested police evacuated 17 residents, but Fire Chief Dale McLean said the number grew by more than five times over the course of the afternoon and evening.
"We've had a number of homes that are being evacuated and they're being sent to our reception centre, so now our numbers for the reception centre are up around 100," he said.
Michael McDonald, a reporter with the local radio station CHNL, found himself at the heart of the story because he lives in the trailer park.
"I have heard from some people that they've got water right in their living rooms, rivers running through their trailers is what they've told me," he said.
Exactly why the rain turned into a muddy river and flooded the trailer park is unknown, although assistant fire chief Curtis Bossert said at one point that reports suggest a debris dam let loose above a nearby road.
But the city's utilities manager Mike Firlottee is blaming a blocked outfall.
The city said in a statement there have been no reported injuries, and it has opened an emergency reception centre at Interior Savings Centre Parkside Lounge, where it is asking residents to register.
The same storm cut power to about 2,800 BC Hydro customers, although the service has now been restored.
Environment Canada issued a severe thunderstorm watch for the South Thompson region, noting the weather system was capable of producing strong wind gusts, large hail and heavy rain.
(CHNL, Kamloops This Week)