Sounds like outdoor dining will have to close up under bad weather conditions. Alot of work, but it is the only way to take advantage of using outdoors to make some money.
thing is, this was a storm that all the forecasters said was not tracking towards Arlington and Alexandria. You will have a lot of trouble if you shut down dining based on t-storm watches because they impact wide areas. But if you only do it on t-storm warnings (that is, a specific storm is identified and its likely track put it over an area at a certain time), then you can go from no worries to clobbered in a space of 45 minutes. That's a heck of a spot to be in if you are basing your night's earnings on outdoor dining.