Terminology of weather forecast

Common nouns, terms and definitions in 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 than10mm; 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.

Have an impact on crops.

Freezing rain: raindrops freeze on the ground below 0℃, also known as rain songs (frozen by fog drops, called fog songs), which often fall off from power lines, making

The road surface is frozen, which affects 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: white frost appears when water vapor condenses into white crystals on the ground and the surface of objects below 0℃. Those with low water vapor content and no frost are called black frost pairs.

All crops have freezing injury, 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, and the warm air in front of the trough is active in rainy and snowy weather.

After the cold air is controlled, the wind cools the 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. What a stormy day on the cold front.

Gas, windy weather in the front after; 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. Wind plumes are represented by 3 or 4 short strokes and triangles.

The force of strong wind is perpendicular to the right side of the end of the mast (northern hemisphere).

Meteorological terminology

1. Time division: The daytime mentioned in the weather forecast refers to 8: 00 to 20: 00 local standard time, in which 17: 00 to 20: 00 is called evening; Call night after 20 o'clock to 8 o'clock the next day.

2. Weather conditions (the division between cloudy and sunny): sunny means that the amount of clouds in the sky is less than 30% (that is, 30%) all day; Cloudy is the sky condition when there are 4-70% medium-low clouds or 6- 10% high clouds in the sky; Partial cloudy is the sky condition when there are 1-3% medium-low clouds or 4-50% high clouds in the sky; A cloudy day is a weather phenomenon in which the sky is dark and the clouds are densely covered, or even if there are gaps in the clouds, the sky still feels dark (accounting for more than 80% of the total amount of clouds), and occasionally weak sunlight can be seen from the gaps in the clouds.

Fog: A visible aggregate of a large number of tiny water droplets (or ice crystals) suspended in the atmosphere near the ground. The only difference between fog and clouds is whether they touch the ground or not. Fog greatly reduces the horizontal visibility of the ground. According to the regulations of the International Meteorological Organization, when the visibility drops below 1 km, it is called fog.

Cloud amount and cloud height: Cloud amount refers to the percentage of clouds covering the sky; Cloud height refers to the vertical distance from the bottom of the cloud to the ground of the station.

3. Temperature: The temperature mentioned in the weather forecast refers to the air temperature measured in the open air without direct sunlight (generally measured by blinds). The highest temperature is the highest temperature in a day, which generally appears at 14- 15, and the lowest temperature generally appears at 5-6 am.

4. Precipitation: Precipitation includes rainfall, snowfall, sleet and hail.

Rainfall: The meteorological department generally refers to the rainfall within 24 hours. Rainfall is generally divided into eight levels: sporadic light rain, light rain, shower, moderate rain, heavy rain, heavy rain, heavy rain, heavy rain, heavy rain and heavy rain. According to the 24-hour precipitation (mm), the rainfall grades are: light rain 0. 1 ~ 9.9, moderate rain 10.0 ~ 24.9, heavy rain 25.0 ~ 49.9 and heavy rain 50.0 ~ 99.9.

Hail: Hard spherical, conical or irregularly shaped solid precipitation.

Snowfall is divided into light snow, medium snow, heavy snow, blizzard and blizzard according to snowfall. Among them, blizzard is the snow with high snowfall intensity (the horizontal visibility distance is less than 500m during snowfall or the snowfall within 24 hours is greater than15 mm); Blizzard, also known as blizzard, is a weather phenomenon that strong winds carry a lot of snow and it is impossible to judge whether there is snowfall at that time, and the horizontal visibility is less than 1km.

5. Wind: Wind refers to the horizontal flow of air. Expressed by wind direction and wind speed: the wind direction is divided into sixteen directions, which refers to the direction in which the wind blows; Wind speed is expressed in wind scale or m/s, and it is divided into average wind speed represented by 2-minute average situation and instantaneous wind speed represented by instantaneous situation.

The strength of the wind is expressed by the wind speed, generally measured by the size of the wind or how many meters/second. There are thirteen grades:

Static wind: that is, level 0 wind.

Breeze: that is, level 4 wind. Wind with a wind speed of 5.5-7.9 m/s

Breeze: that is, level 3 wind.

Strong wind: that is, 8 winds. Wind with an average wind speed of17.2-20.7m/s.

Strong wind: 10 wind.

Storm: 1 1 wind. A wind with a wind speed of 28.5-32.6 m/s.

Hurricane: the wind above 12. (Tropical cyclones with the maximum surface wind force 12 or more near the center are called typhoons in the northwest Pacific).

Gust: a sudden change in instantaneous wind speed, sometimes accompanied by a change in wind direction, which lasts for a short time.

Black wind: a strong sandstorm weather with strong instantaneous wind speed and extremely low visibility.

Dry-hot wind: agricultural meteorological disaster weather with high temperature and low humidity and certain wind force.

Cold dew wind: Cold damage caused by cold air invasion in autumn, which reduces rice production.

Monsoon: the prevailing wind direction changes with the seasons, and it is almost the opposite within one year.

Trade wind: a large-scale airflow blowing from the south side of the subtropical high to the low-pressure area near the equator in the lower atmosphere.

Sea breeze: the wind blowing from the sea to the land in coastal areas due to the warming of the mainland surface during the day.

Land wind: In coastal areas, the surface wind blowing from the land to the sea due to the radiation cooling of the mainland at night.

Downburst: A strong downward airflow, usually causing scattered disastrous winds at or near the ground.

Wind shear: the spatial variation of wind vector in a specific direction.

Mountain wind: in mountainous areas, due to thermal reasons, the wind blowing from the hillside to the valley at night.

Valley wind: in mountainous areas, the wind blowing from the valley to the hillside during the day due to thermal reasons.

Gale: A sudden strong wind of short duration. Often accompanied by thunderstorms.