Weather refers to the atmospheric conditions in a specific place at a specific time. There are many factors that impact on our weather and by studying these, meteorologists are able to predict the weather by studying patterns. Some of the important features of weather include:
Temperature: This is the most commonly used measurement of our weather. It is influenced by factors such as altitude, proximity to water, mountains and latitude (how far from the equator). The closer to water, generally the more mild the temperature and less variation.
Atmospheric pressure: This is the weight of the atmosphere overhead. Changes in atmospheric pressure signal shifts in the weather. In NSW, a high-pressure system usually brings dry, settled weather and light winds. Low-pressure systems usually mean cold, wet, and windy weather. The Bureau of Meteorology (BOM) have produced an excellent guide to reading and interpreting weather maps, including detailed information on different atmospheric pressure systems. Click here to access this.
Wind: Is the movement of air across the earths surface. It is influenced by many factors including changing landforms such as mountains, changing temperatures or changes in barometric pressure (see above). Understanding and predicting winds can be important in planning for outdoor activities and for setting up camp.
Humidity: This refers to the amount of water vapor in the air. Humidity is usually expressed as relative humidity, or the percentage of the maximum amount of water air can hold at a given temperature. Cool air holds less water than warm air. This is why areas closer to the equator and also near water tend to be more humid. Excess water vapor will fall as precipitation. Clouds and precipitation occur when air cools below its saturation point. This usually happens when warm, humid air cools as it rises.
Clouds: Clouds have more of an impact on our weather than just producing rain. They can act as a blanket, trapping the heat in close to the earths surface, making for warm nights. During the day, clouds can also act to cool the temperature because they reduce the amount of heat from the sun entering our atmosphere. Different cloud types have different impacts on the weather. For more information on cloud types, click here.
Precipitation: Different forms of precipitation can include any form of liquid or solid water that falls to the earth such as rain, snow, hail or sleet. Many factors influence how much precipitation an area has including humidity, access to water and changing temperature patterns such as wind or different terrains such as mountains.
Gaining an understanding of the features of weather in a local area can dramatically impact on the success or otherwise of an outdoor activity. This was discussed previously in the core topic. To review this info, click here.