Vocab Page E1.4 Low Pressure- A low pressure system is a whirling mass of warm, moist air that generally brings stormy weather with strong winds.

Transcription

1 Low Pressure- A low pressure system is a whirling mass of warm, moist air that generally brings stormy weather with strong winds. When viewed from above, winds spiral into a low-pressure center in a counterclockwise rotation in the Northern Hemisphere. A low pressure system is represented as a big, red L.

2 High Pressure- a whirling mass of cool, dry air that generally brings fair weather and light winds. When viewed from above, winds spiral out of a high-pressure center in a clockwise rotation in the Northern Hemisphere. These bring sunny skies. A high pressure system is represented as a big, blue H. Cold Front- A cold front is a boundary between two air masses, one cold and the other warm, moving so that the colder air replaces the warmer air. A cold front is represented as a blue line with the teeth pointing toward the direction on movement.

3 Warm Front- A warm front is a boundary between two air masses, one cool and the other warm, moving so that the warmer air replaces the cooler air. A warm front is represented as a red line with half circles pointing toward the direction on movement. Stationary Front- A stationary front is a boundary between two air masses that more or less doesn t move. A stationary front is represented as an alternating warm and cold front symbol.

4 Occluded Front- An occluded front is a combination of two fronts that form when a cold front catches up and overtakes a warm front. An occluded front is represented as a purple line with teeth and half circles. Temperature- a measure of how fast the atoms and molecules of a substance are moving. Temperature is measured in degrees on the Fahrenheit, Celsius, and Kelvin scales.

5 Anemometer- an instrument for measuring wind speed. Climate- an area's long-term weather patterns. The simplest way to describe climate is to look at average temperature and precipitation over time. Humidity- amount of water vapor in the air. Weather- what conditions of the atmosphere are over a short period of time

6 Relative Humidity- it is a measure of the actual amount of water vapor in the air compared to the total amount of vapor that can exist in the air at its current temperature. Warm air can possess more water vapor (moisture) than cold air, so with the same amount of absolute/specific humidity, air will have a HIGHER relative humidity if the air is cooler, and a LOWER relative humidity if the air is warmer. What we "feel" outside is the actual amount of moisture (absolute humidity) in the air.

7 Weather map- displays various meteorological features across a particular area at a particular point in time and has various symbols which all have specific meanings. Stratus- Are uniform grayish clouds that often cover the entire sky. Stratus clouds mean rain if it is warm and snow if it is cold. They look like a huge gray blanket that hangs low in the sky.

8 Cumulus- Are white, puffy clouds that look like pieces of floating cotton. Cumulus clouds are often called "fairweather clouds". Cirrus- Are the most common of the high clouds. They are composed of ice and are thin, wispy clouds blown in high winds into long streamers. Cirrus clouds are usually white and predict fair to pleasant weather.

9 Fog- A thick cloud of tiny water droplets suspended in the atmosphere at or near the earth's surface that obscures or restricts visibility