Weather
What is weather and how can we predict it?
Weather vs. Climate
What is weather?
Weather is sunshine, rain, snow, wind, and storms. It's what is going on outside right now. The weather is different at different places around the planet. In some places it's sunny right now, while in other places it's snowing. Many things affect the weather including the atmosphere, the Sun, and the season.
The science of weather is called meteorology. Meteorologists study the weather and try to predict it. Predicting the weather is not easy as there are so many factors and variables involved.
*Taken from https://www.ducksters.com/science/weather.php
Weather vs. Climate
Weather is the current conditions at a given time. Weather is constantly changing from day to day. Climate is different. Climate is the weather patterns expected for a region or season. Climate is determined by collecting weather data over 30 or more years.
Different places in the world tend to have different kinds of weather which we call their climate. Some places, like San Diego, California are warm and sunny for much of the year. While others, like the tropical rain forests, get rain most every day. Still others are cold and snowy most of the year, like Alaska.
- Adapted from https://www.ducksters.com/science/weather.php
Measuring Weather
What tools to meteorologists use?
Meteorologist get the information needed to forecast weather from both the lower and upper atmosphere. They use weather balloons, radars and satellites in the upper atmosphere. From the surface of the earth meteorologist gather information which includes cloud cover, temperature, precipitation, dew point, air pressure and wind speed. Combining all of this data results in the formation of weather maps.
How can we read a weather map?
A weather front is the leading edge of a weather system. A front is the boundary between two different air masses. One type of front is a warm front which is represented by a red line with semicircle bumps that point in the direction that it is moving. Warm fronts happen when warm air moves over the colder air. This may cause overcast skies and drizzle. A cold front is a blue line with triangles pointing in the direction that the front is moving. A cold front occurs because colder air is moving toward warm air. The cold air will push under the warm air this in turn lifts the warm air which condenses the water vapor causing clouds. Often cold fronts will cause the development of thunderstorms and even the possibility for tornadoes. Another type of front is a stationary front which is composed of both red semi circles and blue triangles. As students’ observe weather fronts over several days, they will see that the fronts move from west to east across the United States. When students are predicting weather it is important that they understand the weather that is often associated with fronts.
Air pressure is another important aspect of weather maps. Air pressure is represented with an H and L. High pressure brings fair weather and the pressure system moves in a clockwise motion. Low pressure is caused by air rising and result in cloudy or even stormy weather. These systems move in a counterclockwise motion. When teaching weather maps students need to understand the characteristics of the weather when they see the symbols H and L on a map.
There are many different types of weather maps. One map is the satellite map which shows the cloud cover over a specific area. Radar maps show precipitation. Temperature map show the high and low temperatures for a region. Current wind maps show the wind speed and direction. Current surface maps show the fronts, precipitation and the High and Low pressure systems. Students should be familiar with a variety of maps and be able to discuss the current weather conditions in a specific location along with predict the weather that is headed for the location based on fronts, precipitation and winds to the west of the city.
How do clouds indicate weather?
Clouds are also an indicator of the current weather conditions and the weather to come. There are three main types of clouds, cirrus, cumulus, and stratus clouds. Cirrus clouds are thin wispy clouds also known as mares’ tails. They are high clouds 25,000 to 40,000 feet above the ground. They are made up of ice crystals and they signal an upcoming storm or weather change. Cumulus clouds are puffy and look like cotton balls. They form 2,000 to 20,000 feet above the ground. Usually they mean fair weather, but they can grow into large thunderhead known as cumulonimbus clouds. The lowest clouds are the stratus clouds. They form close to the ground as fog or to about 6,5000 feet above the ground.. These clouds are low, flat and gray and they often cover the sky. These clouds produce drizzy, mist or rain.