STEPHEN (Interrupting): Cool. Did they say when we'll get our first thunderstorm?

DAD: No, it wasn't a forecast. They were talking about storm safety... what to do if severe weather comes along.

THERESA: I know what I'll do. I'll head straight for the porch to watch the clouds build and the lightning flash. I want to get a comfortable chair so I won't have to sit on the floor.

The shared theme in the provided excerpts is the multifaceted reactions to thunderstorms, from fear to fascination, and includes practical safety measures during such severe weather.

Explanation:

The excerpts presented highlight the various characters' relationships and reactions to thunderstorms. These narratives convey a mixture of anticipation, fear, practical safety concerns, and reflections on personal experiences with storms. Characters like Bess and Theresa express fear, preferring safety during a storm, while others like Venters seem more captivated by the natural display. The notion of listening to safety advice, like not using electric appliances during a storm, is juxtaposed against the desire to experience the phenomenon directly, as with watching the lightning flash from a porch.

Despite the varying attitudes towards storms, the shared understanding is the awe-inspiring and potentially dangerous nature of thunderstorms. The powerful imagery of darkening skies, the rumbling of thunder, and the flashes of lightning strongly evoke the essence of stormy weather. The safety precautions mentioned, such as not beginning a baking project during a storm, further hint at the gravity of a storm's potential impact.