One of the first things you probably do every morning is look out the window to see what the weather is like.
Looking outside and listening to the day’s forecast helps you decide what clothes you will wear and maybe even what you will do throughout the day. If you don’t have school and the weather looks sunny, you might visit the zoo or go on a picnic. A rainy day might make you think about visiting a museum or staying home to read.
Thus, Weather is the day-to-day state of atmosphere and pertains to short term changes in conditions of heat, moisture and air movement. Weather results from processes that attempt to equalize the differences in the distribution of net radiant energy from sun. Areas located closer to the Earth’s equator receive more energy than areas that are closer to the Earth’s poles. In other words, the instantaneous state of atmosphere can be called as weather. It is usually expressed as fine, fair, foggy, cloudy, rainy, sunny or windy weather.
It refers to the sum total of the atmos¬pheric conditions in terms of temperature, pressure, wind, moisture, cloudiness, precipitation and visibility of a particular place at any given time. In fact, it denotes short-term variations of atmospheric condi¬tions and it is highly variable. It contrives phenomena in the atmosphere of our planet. Different surfaces such as forests, oceans, streams, mountains, and ice sheets also influence weather conditions. At different times of the year, sunlight falls on the Earth’s surface at different angles. So, at one period of time, one hemisphere receives more direct sunlight than another. This effect is known as the effect of the sun’s angle on climate, causes seasons.
Weather is an important factor to determine the success or failure of agriculture. All the agricultural operations from sowing to harvest of crops depend on the mercy of weather. It also plays a major role in the productivity of a crop in any region as the excess or shortage of elements of weather exerts a negative influence on crop growth, development and final yield.
There are certain factors that can lead to the variation in the weather such as geographic surface features such as large bodies of water and mountain ranges modify the wind characteristics and hence the meteorological parameters :-
(a) A mountain range in the path of prevailing wind creates moist conditions on the windward side and dry conditions on the leeward side. Air cools adiabatically to the dew point as it rises up the mountains. The air that is forced upward by the mountain range loses its moisture and becomes a dry mass when it goes over the top. This is called the aerographic effect (relief effect), which is different from the usual rainfall without mountains. This is how topography influences weather through variation in temperature and wind.
(b) Water is normally warmer than the surrounding land. When wind blows over a large body of water, it picks up moisture, thus creating a more moderate leeward condition. The leeward side of the body of water is subjected to less temperature fluctuations (relatively stable weather) compared to windward side. Windward side is suitable for drought tolerant crops and leeward side to relatively drought sensitive crops. North facing and south facing slopes may have different weather and thus different natural vegetation. Therefore, these sites have different crops grown in the respective areas and so on.
Similarly, there are six main components, or parts, of weather. They are temperature, atmospheric pressure, wind, humidity, precipitation, and cloudiness. Together, these components describe the weather at any given time. These changing components, along with the knowledge of atmospheric processes, help meteorologists—scientists who study weather—forecast what the weather will be in the near future.