The Courier-Journal, Matt Stone) NO SALES, NO ARCHIVE, MAGS OUT, Associated Press
As art teacher Barbara Sprawls tries to quiet students, fifth-grader Dakota Diehl takes cover along with other students at Kenwood Elementary in Louisville Tuesday morning, Jan. 17, 2012 during a tornado warning. The National Weather Service on Tuesday issued a tornado warning for Jefferson and western Oldham counties in Kentucky and southern Clark and eastern Floyd in Indiana. The warning expired without incident.

LOUISVILLE, Ky. — Powerful spring-like storms lashed portions of Kentucky with fierce winds Tuesday, uprooting trees and yanking down power lines that clogged roads and left thousands without electricity.

Two tractor-trailers overturned on a Louisville-area highway during the storm, and one of the drivers told authorities that high winds caused the accident.

The fast-moving storm triggered a series of tornado warnings ahead of an expected sharp drop in temperatures from the balmy 60s in the morning to the more seasonal 20s by Tuesday night.

The Louisville area appeared to be among the hardest hit, though storm warnings stretched into south-central Kentucky.

The National Weather Service was assessing "strong evidence" of a tornado touchdown in a section of eastern Jefferson County, said hydrologist Mike Callahan. Television aerial footage in that area showed a path of damage including downed trees that covered roads and landed on roofs.

Wind gusts topped 60 mph in the area and were likely much higher in the hardest-hit areas, but the weather service was still trying to determine how high, Callahan said.

The storms were triggered by an approaching cold front that forecasters said would cause temperatures to plummet.

"Anymore it's not rare at all," Callahan said of spring-like storms in winter. "We have it almost every year lately."

The southbound lanes of the Interstate 265 were shut down after the two tractor-trailers overturned, one ending up in the median and the other in a ditch. The road was strewn with debris.

One of the semi drivers told emergency officials that high winds had knocked over his rig, said Jody Johnson, a local MetroSafe spokeswoman. She said the other semi driver had to be extricated and was taken to a local hospital with unspecified injuries.

At the private Kentucky Country Day School, students were ushered to designated safe areas as the storm approached, said school spokesman Jeff Topham. Damage appeared limited to some downed trees on the school grounds, he said.

Thousands of students in schools across the affected area participated in tornado drills, and power was knocked out to a handful of schools in Jefferson County.

Meanwhile, Louisville Gas & Electric Co. reported more than 13,700 customers were without power, mostly in Jefferson County. LG&E spokeswoman Liz Pratt said crews were responding to downed power lines and damaged power poles.