Weather (5.P.2.1, 5.E.1.1, 5.E.1.2, and 5.E.1.3)

Weather systems and concepts related to weather
water cycle
The water cycle is how water moves around the planet from clouds, plants, oceans, lakes, ground, etc. It is a never-ending cycle and is driven by the sun's energy.
heat energy
The sun provides heat which aids in the process of evaporation. Changes in heat energy determines the state of water from solid, liquid and gas.
Gravity plays a role in precipitation. Once water vapor condenses in the atmosphere it can become too heavy and will fall back to the surface of the earth in the form of rain, sleet, hail, or snow.
Evaporation is the process in which liquid water is changed into water vapor. This process speeds up as there is more heat energy. Our sun is the driving force in evaporation.
Condensation occurs when there is a loss of heat energy and water vapor clusters together to form clouds or water droplets. This process can occur anywhere there is a loss of heat energy so when we see water on the grass in the morning it could be dew, or water that condensed close to the ground.
Water is absorbed by plants through their roots. When heat energy increases water can be evaporated into the atmosphere through the leaves of the plant. PLANT SWEAT!
Water percolates into the ground after the process of precipitation. Homes that rely on a well as a source of water have a pump that takes water from underground and brings it to the house to be used.
Water that runs over the surface of the earth. Water flows towards the lowest elevation. It will begin in mountain streams and eventually flow towards the sea or ocean pulled by gravity.
The sun is the driving force for most abiotic or biotic cycles on earth. Heat energy from the sun is responsible for the processes that occur in the water cycle. Without the sun there would be no cycle.
A living or once living component of the environment. Plants and animals are biotic.
Components in the evironment that are not living such as water, light, heat, soil, and so on.
Jet stream
The jet stream consists of cold, fast moving winds high in the atmosphere. During the winter months the jet stream dips farther south bringing colder air farther into to the southern states. In the summer months the jet stream is positioned farther north so the warmer tropical air pushes farther north.
Gulf Stream
The Gulf Stream is a very powerful current in the Atlantic Ocean. Warm water close to the equator is pushed westward by trade winds. This warm water begins in the Gulf of Mexico flows along the eastern seaboard of the United States and moves toward the European shores. The climate in these areas are warmer due to this flow of warm water.
Prevailing Westerlies
The United States' weather patterns are greatly influenced by the direction of the wind as it flows across the country. Prevailing Westerlies move in a west to east pattern. Therefore, most of the weather we experience move from the western part of the country towards the eastern portion.
El Nino
Surface temperatures of the ocean become unusually warm in the Pacific Ocean. When this occurs there are major changes in weather patterns in the United States and South America. Rainfall increases in the United States and Central American causing destructive flooding while causing drought conditions in the West Pacific.
When we measure temperature we are determining how hot or cold the air is. The temperature of air masses plays a crucial role in weather conditions.
air pressure
Air has weight and takes up space. Air surrounds us and pushes down on us at about 15 pounds per square inch. We don't know this is occurring because the air inside our bodies pushes outward with the same force. We can feel the difference in the air pressure when we go to the mountains and the air pressure is not as great. That's when the air on the inside of our bodies pushes out with more force and our ears "pop".
The amount of water vapor in the air. Humidity is measured using a hygrometer.
The measure of the distance you are located from the equator. As you move from the equator and travel toward the poles the latitude increases. As it increases so does the climate. Locations farther from the equator have colder climates.
The measure of the height above sea level. This affects climate in that the higher above sea level the colder the climate. For example, when traveling to the NC mountains the temperature will be colder than the temperature here in Denver and even colder than the beach (at sea level).
The earth is divided into two parts. The equator is one dividing line. The half to the north is the Northern Hemisphere and the half to the south is the Southern Hemisphere. It is important to understand as the earth revolves around the sun parts of the earth receive more direct sunlight. This is what causes the different seasons during the year. We live in the northern hemisphere.
An instrument that measures how hot or cold something is. When used for weather it measures air temperature.
An instrument that measures air pressure. As the reading on the instrument drops to a lower number we say the air pressure is low. Low air pressure can mean rain or stormy weather. As the air pressure rises we say the air pressure is high and the weather is fair.
An instrument that measures wind speed. Wind speed is measured in miles per hour.
wind vane
An instrument used to measure wind direction. It points to the direction from which the wind is blowing.
rain gauge
An instrument used to measure the amount of precipitation. (To measure precipitation that falls in a solid form such as snow, sleet or hail it has to be melted first before getting the measurement. About 10 inches of snow equals one inch of rain.)
sea breeze
During the day the sun heats the earth's surface. Water heats and cools slower than land. Therefore, during the day the ocean temperature will be cooler than the land. Cool air from the ocean will blow towards the land as the warm air over rises.
land breeze
At night the land cools faster than the water. Cool air over the land blows toward the ocean as the warm air rises.
stratus clouds
These clouds are lower lying clouds. They form in layers and blanket the sky. These clouds can bring overcast conditions as well as rain or snow. When it rains or snows those clouds are called nimbostratus (nimbo in Latin means rain or storm cloud).
cirrus cloud
These clouds form high in the atmosphere. They are so far from the earth's surface they are made up of ice crystals. High winds blow them out to look like feathers or horse tails. The clouds mean fair weather but can indicate a change in weather later.
cumulus cloud
These clouds look like puffy cotton balls in the sky. The weather is fair when these clouds are around but whenever they grow upward they can bring thunderstorms.
cumulonimbus cloud
Cumulus clouds that grow upward can develop into clouds that bring thunderstorms or severe weather. These storms are associated with lightning, thunder, and sometimes hail or tornadoes.
Coriolis Effect
Winds blow around the earth's surface from areas of high pressure to areas of low pressure. However, they do not blow in a straight line. They will curve in different directions depending on your location on earth. Winds affecting our weather come from the west and are called Prevailing Westerlies.
warm front
Faster-moving, lighter air moves over colder, heavier air. As this happens the warm air rises and cools causing the water vapor to condense causing thicker cloud cover and light rain that could last a few days. Temperatures will be warmer.
cold front
Faster-moving, heavier air moves under warmer, lighter air. It pushes warm air up very quickly causing the water vapor in the warm air to condense and form clouds. Tall cumulonimbus clouds may form bringing short but very heavy rains, storms, or even tornadoes.
stationary front
Two air masses meet and stop moving this brings clouds and precipitation, sometimes over a few days.
occluded front
Warmer air becomes trapped between two cold air masses usually during a storm. As winds swirl in the counterclockwise direction, the cold front moves faster and catches up to the warm front trapping it.
A large storm that brings strong winds and heavy rain. It forms off the coast of Africa and gains strength over warm ocean waters. Once this storm moves over land it causes flooding, beach erosion and damage to property.
A violent storm with rotating air that extends from thunderstorms towards the ground. They are fast moving and can cause extensive property damage. They are different from hurricanes in that they form over land and do not last as long as hurricanes.
The condition of the atmosphere at a certain time and place.
Conditions are recorded over a long period of time to determine a pattern for an area. Temperature, rainfall and wind speed/direction are used.
Imaginary line around the center of the earth. Temperatures around the equator are very warm creating tropical climates. As you move farther away from the equator towards the poles, the temperature decreases. Warm water and air around the equator moves towards the poles while the air and water from the poles flow downward toward the equator.
high pressure
When air is cold it is more dense and heavy. This heavier air pushes down on us more than warm air. Fair weather and cooler temperatures are observed.
low pressure
When air is warm it is lighter and less dense. Air that is light exerts less pressure on us. As this air rises it will condense and cause cloudy conditions and sometimes rain.