Tokyo Life

Protect Yourself from Sudden Downpours

*This article originally appeared on a website operated by Tokyo International Communication.

Sometimes heavy rain starts falling suddenly, and it continues for several hours in the same area. This kind of rain can create severe damages in a short time. Let's think about how to protect ourselves from sudden downpours like this.

 

Understanding the Reasons for Sudden Downpours

Reasons sudden downpours occur

When warm and moist air rises up from the Earth's surface, chills, and forms clouds up in the sky, these are called cumulonimbus clouds. These clouds cause heavy rain. They are also involved in lightning and tornadoes.

 
Preparations for heavy rains
 

Before Sudden Downpours

Check the weather forecast before going out.

Before going out, check the weather forecast.
If the weather forecast states "atmospheric conditions are unstable," be careful. This means that there is warm air on the Earth's surface and cold air in the sky. This means that cumulonimbus clouds could form, possibly causing a sudden downpour, lightning, or tornadoes.
Other expressions to look out for include "weather could change easily" and "sudden lightning storms." If the weather forecast includes any of these, be careful.

 

Check the weather forecast for the near future.

Pay attention to the weather forecast when you are out as well. Try using the following sites to check the weather forecast for the near future.

This site indicates locations and severity of rain in the next 30 minutes. You can also view lightning and tornado information.

 
Preparations for heavy rains
 

You can also use this site for detailed information about rain conditions in Tokyo and the surrounding area. By looking up rainfall data from the past two hours up until now, you can get a sense for where and in what severity rain is likely to fall in the near future.

 
 

Pay attention to changes in the sky and atmosphere

If you notice any of the following changes in the sky and atmosphere, it means that cumulonimbus clouds are getting closer.

  • Black clouds are moving closer.
  • You can hear the sound of thunder.
  • A cold wind is blowing.
 

This means that heavy rain or lightning could strike soon. Tornadoes are also a possibility. Immediately evacuate to a safe place.

 

When Sudden Downpours, Lightning, and Tornadoes Occur

When sudden downpours occur

When heavy rain falls in the same location for several hours, this can cause rivers and sewers to overflow in a short time.
When sudden downpours occur, be careful of the following.

  • Move away from rivers and other standing water immediately.
  • There is a risk of water flowing inside, so do not go into basements or other underground areas.
  • There is a possibility of flooding, so do not use underground passageways.

When lightning strikes

When lightning strikes, it's dangerous to be in an open area with nothing else around you.
To protect yourself from lightning, take the following actions.

  • Even if the sound of the thunder is still far away, evacuate immediately.
  • Run into a building or car.
  • Do not stand under trees.
  • If there is nowhere to run nearby, lower yourself close to the ground.
 

When tornadoes occur

When a tornado comes close, all kinds of objects go flying at incredible speeds.
To protect yourself in a tornado, take the following actions.

  • Run into a sturdy building.
  • Inside the building, close the curtains and windows, then keep as far away from the windows as possible.

In addition, strong winds may knock down power lines. If you see any fallen lines, do not touch them under any circumstances.

 
Preparations for heavy rains
 
List