Nebraskans can't stop thinking about the weather for a simple reason: It's impossible to ignore. Freezing cold can replace blistering heat in just a few days' time. A single storm can unleash a blizzard, tornadoes and flooding as it crosses the state. World-Herald weather reporter Nancy Gaarder explains why Nebraskans can't stop watching the skies. The newspaper's photographers show how the state's wide-open landscape provides the perfect stage for spectacular storms overhead and the sunset encores as the clouds pass.--