Common terms of weather forecast

Sunny day: the cloud cover in the sky is less than 30%.

Yin: The amount of clouds in the sky accounts for more than 90%.

Fog: A large number of tiny water droplets or ice crystals float in the air near the ground, and the horizontal visibility drops below 1 km, which affects transportation.

Light rain: the daily precipitation is less than 10 mm.

Heavy rain: the daily precipitation is 25.0-49.9mm..

Thunderstorm: Intermittent precipitation accompanied by lightning and thunder.

Hail: With the violent vertical movement in the cumulonimbus cloud, small hail nuclei repeatedly rise, condense, fall and melt, and grow into small ice cubes with transparent layers, which have an impact on crops.

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

Sleet: The temperature near the ground is slightly higher than 0℃, and wet snow or rain and snow drop at the same time.

Xiaoxue: The daily snowfall (melting into water) is less than 2.5mm. ..

Medium snow: the daily snowfall (melting into water) is 2.6-4.9 mm.

Heavy snow: the daily snowfall (melting into water) reaches or exceeds 5.0 mm.

Frost: Frost is formed when water vapor condenses into white crystals on the ground and the surface of objects at a temperature below 0℃. If there is little water vapor and no frost, it is said that black frost has freezing damage to crops, which is called frost.

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).