--- title: Weather: pressure, wind, clouds and storms — a lesson of Mova's school · trees and pragmatics description: «Weather: pressure, wind, clouds and storms», a lesson of the world course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Weather is what the air is like at one place and time: hot or cold, wet or dry, calm or windy, cloudy or clear. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/world/15-weather/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [World](https://md.mova.elamur.ai/free/en/corpora/school/world/) / Weather: pressure, wind, clouds and st… # Weather: pressure, wind, clouds and storms Lesson 15 of the world course of Mova's primary school: 17 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/world/15-weather/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/0/) — Weather is what the air is like at one place and time: hot or cold, wet or dry, calm or windy, cloudy or clear. - [1](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/1/) — The air above us presses on everything; this push is called air pressure. - [2](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/2/) — Warm air is lighter and rises, while cool air is heavier and sinks. - [3](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/3/) — Wind is air moving from places where the pressure is high to places where it is low, like air rushing out of an untied balloon. - [4](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/4/) — Clouds form when moist air rises and cools; when the droplets grow heavy they fall as rain, and when the cloud is cold enough the water falls as snow or hail. - [6](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/6/) — It heats the air so suddenly that the air bursts outward with the bang we hear as thunder. - [7](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/7/) — For example, you see the flash before you hear the thunder, because light travels much faster than sound. - [8](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/8/) — Weather is the state of the air at one place and time. - [9](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/9/) — Air pressure is the push of the air above us. - [10](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/10/) — Wind blows from high pressure towards low pressure. - [11](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/11/) — High pressure usually brings calm, dry weather; low pressure often brings clouds, wind and rain. - [12](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/12/) — Snow forms when water freezes into ice crystals inside a cold cloud. - [13](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/13/) — Hail is balls of ice that grow in tall storm clouds, carried up and down by strong winds. - [14](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/14/) — Lightning is a giant electric spark; thunder is the sound of the air it heats suddenly bursting outward. - [15](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/15/) — Light travels much faster than sound, so we see lightning before we hear thunder. - [16](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/16/) — Sound travels about one kilometre in three seconds. - [17](https://md.mova.elamur.ai/free/en/corpora/school/world/15-weather/17/) — A thermometer measures temperature, a barometer measures air pressure, a rain gauge measures rainfall and a wind vane shows the direction of the wind. - ← previous: [The water cycle](https://md.mova.elamur.ai/free/en/corpora/school/world/14-the-water-cycle/) - next →: [Climate zones](https://md.mova.elamur.ai/free/en/corpora/school/world/16-climate-zones/) - ↑ back to [World](https://md.mova.elamur.ai/free/en/corpora/school/world/)