Weather characteristics before the arrival of typhoon

Weather characteristics before typhoon: high clouds appear, thunderstorms stop, visibility is good, land and sea winds are not obvious, showers stop falling, wind direction changes, and sunset glow is special.

1, high clouds appear

The outermost edge of a typhoon is cirrus, a white feathered or ponytail cloud. When this cloud appears in a certain direction and gradually thickens into a dense cirrostratus, it indicates that there may be a typhoon approaching.

The thunderstorm has stopped.

In summer, thunderstorms often occur in mountainous areas and basin areas every afternoon. If the thunderstorm stops suddenly, it means that there may be a typhoon approaching.

3. Good visibility

Two or three days before the typhoon came, visibility improved, and mountains and trees in the distance could be seen clearly.

4. The land and sea breeze is not obvious.

Usually the wind blows from the sea to the land during the day and from the land to the sea at night, which is called sea breeze and land breeze, but this phenomenon is not obvious a few days before the typhoon comes.

The shower stopped and fell.

When high clouds appear, the clouds are getting denser and lower, and showers often fall and stop, which is also a sign of typhoon approaching.

6. Change of wind direction

The southwest wind often blows in summer, and it is also very gentle. However, if it is changed to the northeast wind, it means that the typhoon is approaching and has begun to be affected by the edge of the typhoon, and then the wind speed will gradually increase.

7. Special sunset glow

On 1 and 2 days before the typhoon strikes, when the sun sets, several beautiful radial red and blue rays are often emitted from the western horizon to the zenith, and then converge in the symmetry between the east and the sun. This phenomenon is called anti-twilight.

Characteristics of Typhoon after Landing

1, gale

The wind speed of typhoons is mostly above 17m/s, even above 60m/s ... According to the measurement, when the wind reaches 12, the wind pressure per square meter on the plane perpendicular to the wind direction can reach 230kg. Therefore, typhoons and strong winds and the waves caused by them can throw the 10,000-ton ship into the air and break it, or push it inland. It is also enough to destroy or even destroy buildings, bridges and vehicles on land. Especially in areas where buildings are not reinforced, the damage is even greater.

2. Heavy rain

When the typhoon lands, the rainfall center can drop 100 ~ 300mm, or even 500 ~ 800mm of heavy rain a day. The flood disaster caused by typhoon and rainstorm is fierce and destructive, and it is the most dangerous disaster.

3. Storm surge

When the typhoon moves to land, due to the typhoon's strong wind force and low air pressure, the sea water accumulates strongly in the direction of the coast, the tide level rises sharply, and water waves flood the coast. The storm surge of a strong typhoon can raise the coastal water level by 5 ~ 6 meters. If storm surge meets astronomical high tide level, it can produce high-frequency tide level, which will lead to flood, seawall burst, destroy houses and various building facilities, flood towns and farmland, and cause a large number of casualties and property losses.