Strong stormy weather can cause flash floods. This is when heavy rain pours down on a region and very quickly floods an area. Scientists are trying to find ways to warn people before flooding hits by studying weather patterns.
Forecasters can predict when they believe tornadoes may form with radar research in severe storms. Tornadoes can be extremely devasting ripping through towns and occuring very quickly sometimes with little warning.
A U-boat crew hears the alarm sound and prepares for an emergency dive. After the crew is in position, the captain reveals that it was only a practice drill so they don't get rusty in the event of a real emergency. Such drills help the crew escape the U-boat in the event of a mechanical failure or an attack by an enemy.