NASHVILLE, Tenn. − Thousands of Tennessee residents remained without power Monday after the National Weather Service officially confirmed two tornadoes tore through over the weekend, flattening homes and businesses, and killing at least six people including a toddler.

The Nashville suburbs of Hendersonville, Gallatin and Madison − where three people died − were slammed by a tornado with peak winds of 125 mph, the weather service reported late Sunday.

Northwest in Clarksville, another tornado with peak winds of 150 mph razed homes and left three others dead and dozens injured. Although the complete storm path could take days to determine, survey teams determined the Clarksville twister was on the ground for more than an hour and tracked for 43 miles through Tennessee into southern Kentucky, Josh Barnwell, a meteorologist with the NWS in Nashville told USA TODAY.

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Potentially 13 tornadoes over an 8-hour period

Emergency response officials preliminarily counted 13 tornadoes impacted the state, Barnwell said, though they were continuing to confirm the total number on Monday.

The severe weather outbreak that began early Saturday afternoon and ended about 10 p.m. may be the deadliest December tornado event on record for Middle Tennessee, the NWS reported. The region previously recorded a total of eight tornado deaths, spanning decades of tornado incidents, in December.

In less than an 8-hour period, dozens of people were injured, cars flipped on I-65, trees buckled, and roofs were blown off buildings as shoppers hunkered down in store basements Saturday for what the NWS preliminarily determined was a string of tornadoes.

The first tornado warning was issued at 1:22 p.m. in Stewart County and Montgomery County, where Clarksville is located, some 50 miles northwest of downtown Nashville.

In all, the weather service issued 34 severe weather warnings − 20 which were tornado warnings, Barnwell said. The last warning was issued at 8:30 p.m. near the Alabama border in Coffee County, Tennessee.

"We have not heard of any damage from that area yet," said Barnwell, who added the NWS plans to send survey teams to Coffee County this week.

Tornado ratings confirmed as EF-3, EF-2

On Sunday the NWS confirmed an EF-3 tornado with winds that reached 150 mph touched down in Clarksville.

The tornado that touched down in Madison, Hendersonville and Gallatin received a preliminary rating of EF-2, with winds of 125 mph.

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Storm damage reports

6 dead, dozens sent to hospitals

Officials said six people died in Madison and Clarksville and 83 people were transported to hospitals − 21 in greater Nashville and 62 in Clarksville, The Tennessean, part of the USA TODAY Network, reported.

Nine were in critical condition on Sunday at Vanderbilt University Medical Center in Nashville.

Recovery efforts

As of late Monday morning, just under 20,000 people remained without power in Middle Tennessee, according to power companies including CDE Lightband and Nashville Electric Service.

Scores of residents spent the night in emergency shelters opened by churches and The Red Cross while utility crews tried to restore electricity to customers after near-freezing temperatures hit the Midstate overnight Sunday, the Tennessean reported.

Nashville Mayor Freddie O'Connell said nearly two dozen structures collapsed in Music City as a result of the storm and "countless" others were damaged.

Late Sunday, The Tennessean reported, Gov. Bill Lee and First Lady Maria Lee surveyed tornado damage in Madison, miles from downtown Nashville.

No rain expected in Midstate until weekend

As of 10 a.m. Monday, the temperature at the Nashville International Airport registered at 37 degrees, after dipping into the 20s earlier in the morning.

Conditions were expected to improve Monday night into Tuesday morning, the NWS said.

"We're supposed to warm up a bit," Barnwell said. "It will be a nice calm weather week."Today we'll be in the 40s and tomorrow we may be in the 50s."

A chance of rain in the region is not expected until the weekend.

Contributing: John Bacon and Jorge L. Ortiz, USA TODAY; The Tennessean staff.

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at [email protected] and follow her on X @nataliealund.