After the stores are already empty

Storm risk shows up twice. Once before it hits, when everyone in town wants the same jugs, and once after, when ditches, fuel, and sewage are in water that looked fine yesterday. A kit bought on a clear week is the thing that covers the first problem. You will not win that aisle at 4 p.m. the day before landfall.

• Short stored water means you are in that aisle with everyone else, or you are filling whatever is clean while the tap still has pressure. A bathtub liner can hold wash water. It should be labeled so nobody drinks it in the dark.
• Marking storm or flood puts a portable filter and a weather radio on the list even for three days. The filter is for water you didn't store. It is the wrong tool once fuel or sewage is in it. If officials say the tap is unsafe, use what they tell you to use.
• Three people for 72 hours is nine gallons, plus that filter and radio, plus food, an opener, lights, and first aid. Two weeks jumps the gallons, switches food to buckets, and can add a toilet, because the stay is long and the storm box is checked. The result page is the count. This is only the shape of the risk: too little drinking water, then bad water, then nowhere for waste to go.

Storm does not put a backpack on the list. "May need to leave" does. If your county clears out for hurricanes, smoke, or high water, the risk of a stay-only kit is the morning they tell you to go and the supplies are all in jugs you can't carry. Mark both if both can happen. I don't have your flood map. The radio is how the county still reaches the house after the phone quits.