I am going to use analogies to help you understand the situation, bear with me
I looked at the 10 day jet stream forecast. Mother nature has fired long range missles that will eventually reach the United States. The timing of when they will hit becomes easier to predict as they get closer. Once these missles reach the U.S. a storm will begin forming. Not every missle fired carries the same payload, some have fireworks while others have nuclear warheads. The storm that spawned deadly tornadoes in North Carolina is a good example of a nuclear warhead.
Follow the weather forecasts from now on. If they are forecasting storms, pay attention, and look for these warning signs.
SEVERE THUNDERSTORM WATCH: Storms that can destroy property and kill people may form later.
SEVERE THUNDERSTORM WARNING: A storm that can destroy property and kill people is coming to get you
TORNADO WATCH: Storms with tornadoes may form later.
TORNADO WARNING: A storm probably has a tornado. The part of the storm where the tornado should be is coming to get you