Colliding air masses within tornado alley make for exceptional conditions that allow for vigorously rising air, which is essential for thunderstorms. Storms in the Great Plains regularly reach 10 miles (16 kilometers) into the sky because of these conditions: 1  Winds pushing disparate air masses converge in tornado alley. 2  Colliding air, known as fronts, have nowhere to go, therefore they rise.
Apple's fiscal 2011 10-K report showed that the average size of an Apple Store has creeped up to 8,400 square feet per store, but Needham & Company analyst Charlie Wolf says that the retail stores are bulging at the seams and just aren't big enough.
Supermarkets averaged $39.30 per square foot, followed by home centers, at $30.67. Convenience stores had the lowest costs, at $28.00 per square foot. ExpAnSiOn: The average number of new stores planned for all participating chains for 2012 was 14 (per chain), up from 11 in the previous year.