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.
It is simply the average revenue for every square foot of retail sales space. According to Advanced Retail Management the average regional mall sales per square foot is $341 and most big box retailers average between $250 to $350.Annual sales divided by the total square feet gives you the sales per square foot.ales per square foot of store space can be considered a key measure of efficiency in retail. In the clothing industry, according to RetailSails, sales per square foot for Nordstrom is $400, compared with just $173 for Macyâs. At $350, Saks Fifth Avenueâs sales per square foot approaches Nordstromâs.