The answers would be the following:
1. Natural disasters
2. Lightning
3. Flood
4. Blizzard
5. Tornado warning
6. Earthquake
Here's more about the choices:
Natural disasters are highly unpredictable and it can happen anywhere and at anytime. There are some ways that you can predict some of the natural disasters, but the effects and the gravity of the situation can only be assessed during and after it happens. They can be extreme and loss of life can occur.
Lighting is an electrical discharge that happens when an imbalance occurs between the clouds and the ground and more often, within the clouds itself. There are about 2,000 deaths caused by lightning a year in the world.
Floods can be due to nature but it can also be caused by man. An evacuation plan is a must when it comes to flood-prone areas. Overflowing of rivers is an example of a natural disaster but pollution and deforestation due to activities of human beings also triggers a flood.
Blizzard is a sustained and sever snowstorm. To count as a blizzard winds should be at least 35mph and rage on for an extended period of time. What makes it so dangerous is that snowstorms prevents travel so it is hard to escape from one. Visibility is almost zero, so it would be dangerous to travel when you are caught in one.
Tornado warnings is an alert given to the public when a tornado has already occurred, or a funnel cloud has been spotted. The warning is often in the form of sirens, warning residents near-by to seek immediate shelter. Some residents have their own shelters, while others retreat to the nearest one they could find.
Earthquakes are also natural disasters that are less predictable than others. When an earthquake occurs, it is advisable to evacuate to an open space. The heavy and strong shaking of the ground can easily overturn objects, which could fall.