High winds and whipping rains rammed into Blount County at 5 p.m. Saturday, putting roads in perilous condition and leaving thousands in the dark.
Maryville outage maps alone reported 2,034 customers were without power by 5:30 p.m.
The Tennessee Department of Transportation said on Twitter that motorists in East Tennessee should avoid the roads.
"Severe weather is moving into East Tennessee over the next hour or so," TDOT spokesman Mark Nagi said. "Use extreme caution. Better yet, stay off the roads if possible as standing water will likely occur in some areas."
Severe thunderstorm warnings, a tornado watch and high wind advisories were issued for Blount by the Nation Weather Service in Morristown.
Residents are advised not only to drive with caution but to seek protection in their own homes, preferably in interior rooms or lower building floors.
The bad weather was expected to last until around 9 p.m. to 10 p.m. Saturday.