Weather

Stormclouds

16-008-NASA-2015RecordWarmGlobalYearSince1880-20160120

Navy-FloodedNewOrleans

Day5pressureforecast

07 July - Percent of global area at temperature records - Global warming - NOAA

Great Red Spot From Voyager 1

Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the lowest level of the atmosphere, the troposphere, just below the stratosphere. Weather refers to day-to-day temperature and precipitation activity, whereas climate is the term for the averaging of atmospheric conditions over longer periods of time. When used without qualification, "weather" is generally understood to mean the weather of Earth.

Types of Weather Phenomena

Weather is caused by the differential heating of the Earth's surface by the Sun. This weather variability is due to the Earth's atmosphere's ability to move energy around the globe. Various weather phenomena include rain, snow, fog, wind, and thunderstorms. Extreme weather events such as tornadoes, hurricanes, and blizzards can cause significant damage and loss of life.

Temperature

Temperature is a fundamental aspect of weather and is a measure of the average kinetic energy of the air molecules. Temperatures on Earth can vary widely, from the extreme cold in the Arctic and Antarctica to the intense heat of the desert regions.

Precipitation

Precipitation is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms include rain, snow, sleet, and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor, so it condenses and "precipitates."

Wind

Wind is the flow of gases on a large scale. On the surface of the Earth, wind consists of the bulk movement of air. Wind is caused by differences in the atmospheric pressure. When a difference in atmospheric pressure exists, air moves from the higher to the lower pressure area, resulting in winds of various speeds.

Weather Forecasting

Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location. Humans have attempted to predict the weather informally for millennia and formally since the 19th century. Weather forecasts are made by collecting quantitative data about the current state of the atmosphere and using meteorology to project how the atmosphere will change.

Impact on Humans

The weather has a profound impact on human health, safety, and activities. Extreme weather can lead to natural disasters, causing damage to infrastructure and loss of life. On the other hand, favorable weather conditions can promote outdoor activities and crop growth. Understanding and predicting weather patterns help in planning and preparedness to mitigate adverse effects.

Climate Change and Weather

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It can be a change in average weather conditions or the distribution of events around that average (e.g., more or fewer extreme weather events). Climate change can affect weather patterns, leading to more frequent and intense extreme weather events.