Many organizations have figured out what their inclement weather policy is for employees who cannot get into work. The ones I'm familiar with let the employee take a vacation day or two. If the organization closes its doors due to the severity of the weather then usually employees don't have to use their vacation days.
All the above is fine but I think these policies surmise that the time inclement weather or other events will cause them to be closed is relatively short.
Enter Hurricane Sandy and this is not necessarily the situation. See a Wall Street Journal article Disaster Dilemma: How to Pay Employees Who Missed Work on how different companies were dealing with closures and issues that employees had when they were personally impacted by the storm.
I recall in our King County Pandemic Flu planning the Executive had established the policy that employees would continue to be paid if the County closed its doors due to the implementation of social distancing. The Finance Director at the time pointed out that it is all good and well to do so, but in about six weeks the coffers would be empty and there would be no funds left to pay employees. A nasty little detail that could get in the way!
Now is the time to think through what your organization's policies are for "longer" disaster events that go multiple days and even weeks. For me, I'd like to work for Starbucks!