NASHVILLE, Tenn. (AP) - A cold front is running into very warm air over Tennessee, triggering tornado watches.

The areas covered early Monday include most of West Tennessee and the northwestern corner of Middle Tennessee. the watches are in effect until midmorning, but could be extended and moved on eastward as the line of storms moves through.

Some school systems were delaying the start of classes because of the stormy weather.

Forecasters with the National Weather Service say there is a moderate risk of severe storms in the state.

Temperatures before dawn were in the 70s, but were expected to fall into the lower 30s by late Monday night and early Tuesday.