What does this weather sign mean?

There is a thunderstorm today, a thunderstorm tomorrow and a thunderstorm the day after tomorrow.

Clear: it means that there are no clouds or scattered clouds in the sky, but the cloud amount is less than110, which is called clear. Sometimes there are very high and thin clouds in the sky, but they have little effect on sunlight.

Cloudy: it can be cloudy when the amount of low clouds in the sky accounts for 4/ 10 ~ 7/ 10 of the sky area or the amount of high clouds accounts for more than 6/ 10 of the sky area.

Cloudy day: it is called cloudy when the amount of clouds in the middle and low clouds accounts for more than 8/ 10 of the sky area. Cloudy days are dark days, and little or no sunlight can penetrate the clouds.

Fog: refers to a large number of water droplets or ice crystal particles suspended in the air near the ground. When this aggregate reduces the horizontal visual distance below 1000 meters, it is called fog; When the visible distance drops to 1000 ~ 10000 meters, it is called light fog.

Light rain: it is called light rain when the rainfall in 4 hours is less than 10.0mm or 1 hour is less than 2.5 mm. ..

Moderate rain: the rainfall within 24 hours is 1 0.0 ~ 24.9mm or the rainfall within1hour is 2.5 ~ 8.0mm..

Rainstorm: Rainstorm is called when the rainfall in 24 hours is less than 25.0 ~ 49.9mm or 1 hour reaches 8.1~15.9mm..

Rainstorm: Rainstorm is called when the rainfall reaches or exceeds 50.0mm in 24 hours and 1 hour reaches or exceeds16.0mm.. Heavy rain occurs when the rainfall reaches 100.0 ~ 199.9 mm; The rainfall of 200.0 mm is called rainstorm;

Thundershower: refers to sudden rainfall accompanied by thunder and lightning, which is characterized by short rainfall time, sudden start and end, and great changes in precipitation intensity. Intermittent precipitation accompanied by lightning and thunder.

Hail: It is a kind of solid precipitation. Refers to spherical or conical ice cubes with a diameter of 5.0 mm, and it will rain heavily in the clouds. The shape is also irregular. The monomer is called hail block, which consists of transparent and opaque layers. The diameter of large hailstones can reach 19 cm.

Freezing rain: raindrops freeze on the ground below 0℃, also known as rain storm (frozen by fog drops, called fog storm), and often fall off the power lines, freezing the road surface and affecting communication, power supply and traffic.

Sleet: refers to the precipitation phenomenon that raindrops and wet snow fall to the ground at the same time. When it happens, the near-surface temperature is slightly higher than 0℃. When snow falls into this layer of air, part of it melts into water droplets.

Light snow: refers to the snow whose horizontal visibility exceeds 1000m when it snows, or whose snowfall is less than 2.5mm within 24 hours.

Medium snow: refers to the snowfall with horizontal visibility exceeding 500 ~ 1000 meters or snowfall less than 2.5 ~ 5.0 mm within 24 hours. ..

Blizzard: refers to the snowfall with horizontal visibility less than 500 meters or snowfall greater than 5.0 mm within 24 hours.

Frost: In the transitional season of spring and autumn, the temperature is higher than 0℃ during the day and drops below 0℃ for a short time at night. When it appears, the temperature in the louver shall not be lower than 0℃; Frost often appears on the ground or on the surface of objects.

Low-pressure trough and high-pressure ridge: on the fluctuating high-altitude westerly airflow, the trough corresponds to the low-pressure trough, with active warm air in front of the trough, rain and snow weather, controlled cold air behind the trough, and strong wind cooling weather; The peak corresponds to the ridge of high pressure and the sky is clear.

Cold and warm fronts: A cold front is the front of cold air. At the junction of cold air and warm air mass, cold air pushes towards warm air. It is windy and rainy on the cold front, and windy and cool after the front; On the contrary, it is a warm front, the front is rainy, and it turns cloudy and sunny after the front, and the temperature rises.

Strong wind: expressed by wind vector, consisting of wind mast and wind plume. The wind pole refers to the direction of the wind, with eight directions. The wind plume is represented by 3 or 4 short strokes and triangles, perpendicular to the right side of the wind pole end (northern hemisphere).

Six-level wind: refers to the wind with a wind speed of 10.8 ~ 13.8 m/s above the ground.

Level 7 wind: refers to the wind with a wind speed of 13.9 ~ 17. 1 m/s above the ground.

8- 12 wind: the wind speed above the ground10m is17.2-20.7m/s, 20.8-24.4m/s, 24.5-28.4m/s and 28.5-32.6m/s respectively.

Typhoon: refers to a strong warm-hearted cyclone vortex that occurs in the tropical ocean. When the average wind force near the center reaches 12 or above, it is called a typhoon.