The rules and regulations of insurance, like the rule of law, are not a rigid, mathematical sort of thing. Programming adheres to concrete rules of "if this happens, then that happens." The same goes for engineering and most board games. In matters of insurance, however, quite a bit comes down to judgment and interpretation. 
So, negligence is not just a list of qualifiers. The definition of negligence is failure to act in such a way that most people would reasonably expect you to in such a circumstance. This means that a lack of preparation in the face of a storm warning might qualify as negligence, for example.
This also means that you have some leeway. If you were to do literally everything possible to prevent your home from being damaged during a storm, your insurer could ask why you didn't use your retirement account to build a 60-foot wall around your house. That might be possible, and you might have the means to do it, but it's just not reasonable.
To avoid being found negligent as a homeowner preparing for a storm, there are some simple steps you can take.
- Put your patio furniture away
- Check your gutters
- Put fragile valuables somewhere safe
- Secure your fences
- Clear old limbs and debris from the yard and trim your trees
- Install storm windows
- Stock up on emergency supplies and have a backup plan
- Bring the pets indoors and keep your family safe
If you are a responsible homeowner, your home insurance provider shouldn't have any reason to deny your claim on the count of negligence. You're not really expected to go above and beyond the call of duty, and they don't expect you to reinforce your fence with concrete or put steel shutters over your windows. They just want you to take the appropriate, reasonable steps to safeguard your home and your family from danger.
In short: A lack of preparation can constitute negligence in the eyes of your home insurance provider, but basic preparation should be enough. They just want you to do everything you were already planning on doing to keep your home safe whenever there's danger.