Heavy Rain Warning in Kanto: Updates and Precautions

Locally rapid development of rain clouds in a fairly narrow area

The rain is getting stronger intermittently to the extent that even in the city center the feet get wet.
Looking at the radar image, we can see that rain clouds are developing in a narrow area, although it is quite localized.

Under the developed rain clouds, not only heavy rain but also severe weather phenomena such as thunder, gusts, and hail may occur, so please check the rain cloud radar frequently.

Today, the 14th, it rained widely in the Kanto region, with localized heavy rain at night.

Today, the 14th, the Kanto region will experience intermittent rain in the afternoon, with heavy rain and thunderstorms expected in some places.
Even if the rain is weakening, rain clouds will develop rapidly in a short time, and it is likely that there will be heavy rain. When going out, be careful of sudden changes in the weather, such as sudden heavy rain, lightning strikes, and gusts such as tornadoes.

Also, in the Kanto region, there are places where the ground has become loose due to the rain that has fallen so far. If rain clouds stagnate or develop more than expected, there is a possibility of “warning heavy rain”, and the heavy rain warning area may expand. Be vigilant and careful of landslide disasters in the evening.

What kind of rain is heavy rain?

Heavy rain refers to rainfall of 30 mm or more and less than 50 mm per hour. This is an image of falling like an upside down bucket. In addition, even with an umbrella, about half of the people sleeping inside a wooden house notice the rain. Outside, the road becomes like a river, and cars running on the highway may experience “hydroplaning,” a phenomenon in which a film of water forms between the tires and the road surface, making the brakes inoperable.

In places where heavy rain is expected (places where it rains heavily), it is possible to cause landslide disasters, flooding of low-lying land, and swelling and flooding of rivers, so caution is required.

A sign of a guerrilla downpour

There are three major phenomena that can be precursors to a guerrilla downpour (localized downpour).
① “A black cloud is approaching”
Developed cumulonimbus clouds that bring guerrilla downpours (locally heavy rains) appear pitch black. Black clouds that appear to be moving at high speed, or the sky suddenly turning dark despite the clear sky are also signs of guerrilla downpours (localized downpours).

② “I heard the sound of thunder.”
When you hear a rumbling sound, a thundercloud is approaching. Also, seeing lightning is one of the signs of guerrilla downpours (localized downpours).

③ A cold wind suddenly blew.
From the developed cumulonimbus clouds, cold wind blows down with raindrops. You also need to pay attention to changes in the wind.

If you feel any of these signs, evacuate to a safe place immediately. Also, when a thunder warning is issued or when the weather forecast says “unstable atmospheric conditions” or “sudden change in the weather”, there is a possibility of torrential downpours (locally heavy rain). Please note that there is