Last week’s thunder, even in the middle of a snowstorm, was a reminder that the violent weather of spring and summer is on its way. A more formal notice — Severe Weather Awareness Week — starts Monday.

The main feature of the annual event is the statewide tornado drill, scheduled for Thursday. The drill includes nine Wisconsin counties, where sirens will sound at 1:40 p.m. Five minutes later, the sirens will sound across most of Minnesota, except the northwest part of the state. Local media may interrupt programming as well.

A second drill, scheduled for 6:55 p.m., is intended to get families to re-examine their plans for responding at home.

The weather service points out that, as with actual tornadoes, there will be no all-clear siren during the test. In actual storms, a second siren indicates a second tornado warning.

Each day of the week will bring a focus on a different aspect of severe weather. The Minnesota Division of Homeland Security and Emergency Management has extensive information about each type of severe weather, including how to respond in different circumstances, on its website:

Monday: Alerts and warnings.

Tuesday: Storms, lightning and hail.

Wednesday: Flooding and flash floods.

Thursday: Tornadoes.

Friday: Extreme heat.