By JIM SALTER Associated Press

O'FALLON, Mo. (AP) — A line of severe thunderstorms and tornadoes that swept across the north-central U.S. last week has been classified by the National Weather Service as a serial derecho — the first on record in December.

At least 45 tornadoes have been preliminarily confirmed in the Dec. 15 storms that crossed the Great Plains and Midwest amid unseasonably warm temperatures.

Nebraska, Iowa and Minnesota took the brunt of the damage.

Five deaths were blamed on the weather.

A derecho shares similarities to a hurricane, but it has no eye and its winds come across in a line.

The similarity is in the damage, which is likely to spread over a wide area.