5th to 6th: Rapid Development of Low Pressure System with Strong Cold Air – Hokkaido and Tohoku at Risk of Strong Winds and Heavy Rain

2023-10-04 21:35:07

5th to 6th: Low pressure system develops rapidly Strong cold air for this time of year Hokkaido and Tohoku are at risk of strong winds and heavy rain (Weather forecaster Tomomi Yoshida October 5, 2023) – Japan Weather Association tenki.jp

5th to 6th: A low pressure system develops rapidly. Strong cold air for this time of year. Hokkaido and Tohoku are at risk of strong winds and heavy rain.

October 05, 2023 06:35

A low pressure system will rapidly develop near Hokkaido into tomorrow, the 6th (Friday), so Hokkaido and Tohoku are on alert for strong winds. Strong cold air will flow into the sky for this time of year, and atmospheric conditions will become extremely unstable. Strong rain clouds and thunderclouds will form, and heavy rain is likely to occur in some places. You also need to be careful regarding heavy rain.

A low pressure system is rapidly developing, and the cold air is moving south for this time of year.

Today, the 5th (Thursday), a low pressure system will move towards Hokkaido, and a front will pass from northern Japan to eastern Japan. As a low pressure system rapidly develops near Hokkaido into tomorrow, the 6th (Friday), northern Japan is likely to experience a large pressure gradient.

Additionally, warm, humid air is flowing toward low pressure systems and fronts, making the atmospheric conditions extremely unstable in northern Japan. Until tomorrow, the 6th (Friday), extremely cold air with temperatures below -21°C will flow into the air approximately 5,500 meters above northern Japan, making the atmosphere extremely unstable.

Beware of strong winds and high waves

In Hokkaido and Tohoku, extremely strong winds will blow from the night of today, the 5th (Thursday) until tomorrow, the 6th (Friday), and will cause heavy barges at sea.

The maximum wind speed (maximum instantaneous wind speed) expected today, the 5th (Thursday) is
Hokkaido region: 20 meters (35 meters)
Tohoku region: 18 meters (30 meters)
The maximum wind speed (maximum instantaneous wind speed) expected for tomorrow 6th (Friday) is
Hokkaido region: 25 meters (35 meters)
Tohoku region: 23 meters (35 meters)

What is the expected wave height today, the 5th (Thursday)?
Hokkaido region, Tohoku region: 4 meters
The expected wave height for tomorrow the 6th (Friday) is
Hokkaido region: 7 meters
Tohoku region: 6 meters

Please be on guard for strong winds from today, the 5th (Thursday) night until tomorrow, the 6th (Friday). We also need to be careful of high waves tomorrow, the 6th (Friday).

Beware of heavy rain

Heavy rain with thunder will continue into tomorrow, the 6th (Friday), and there will be heavy rain in some places.

Heavy rainfall is expected in the 24 hours until 6:00 a.m. on Friday the 6th.
Hokkaido region, Tohoku region: 100mm
Heavy rainfall is expected in the next 24 hours until 6 a.m. on Saturday the 7th.
Hokkaido region: 100 to 150 mm
Tohoku region: 50 to 100 mm

Be wary of landslides, flooding of low-lying areas, and rising and flooding rivers. You should also be careful regarding lightning, tornadoes, strong wind gusts, and hail.

What is very strong wind?

Very strong winds refer to winds with an average wind speed of 20 m/s or more and less than 30 m/s. The speed is approximately 70km to 110km per hour, which is regarding the same speed as a car on a highway. This is the kind of wind where you have to hold on to something to stand up, making it difficult for your car to drive at normal speeds. When such winds blow, roof tiles and signboards may fall or be blown away. The instantaneous wind speed is often regarding 1.5 times the average wind speed, and sometimes more than 3 times the average wind speed.

There is a risk of injury from flying objects, so caution is required when performing outdoor activities. If very strong winds are expected, keep flower pots and other objects that can be easily blown away indoors.

5th to 6th: Rapid Development of Low Pressure System with Strong Cold Air – Hokkaido and Tohoku at Risk of Strong Winds and Heavy Rain

5th to 6th: A low pressure system develops rapidly. Strong cold air for this time of year. Hokkaido and Tohoku are at risk of strong winds and heavy rain.