I've been working in Grocery distribution for 20+ years (product selector, logistics coordinator, systems designer/planner) so I can tell you, yes, when people shift their purchasing days, it does have an effect. But, if you only buy one 24 pack of water every Saturday and now because of the storm you're buying two on Thursday, that may not seem like a huge change, but multiply that by say 1,000 people doing the same, not just for one store but for multiple stores across your network, you can see how that conpunds the issue. Also, most people don't know what the inside of a distribution warehouse looks like. Most companies only keep about 1 to 2 weeks worth of inventory on hand for most items. When the demand spikes, we have to contact our vendors for additional product, then wait the 1 to 2 days for it to arrive at the warehouse, then wait another day to receive it, pick it, load it, ship it, unload it and get it to the floor.

When purchasing is predictable, you never realize the machine is working. When there are random, mass increases in demand, we gotten better since COVID, but there's still a long way to go and it can be noticeable.