BACKGROUND:

Meteorology is the physical and chemical science of the atmosphere. Meteorologists study and predict the weather. The interaction of the oceans and atmosphere, including solar radiation helps us understand how weather forms and sustains itself.

Describing the weather and how it changes is recorded on weather maps or synoptic chart. Information on temperature, pressure, wind, radiation, and condensation helps meteorologists to predict future weather patterns. The weather can be divided into its meteorological elements, which describe the physical condition of the atmosphere, land, and oceans.

Temperature. The air temperature is measured by a thermometer over which air is allowed to freely flow over the bulb, but protected from solar and terrestrial radiation.

Atmospheric Pressure. The pressure is the weight of the vertical column upon an area. A barometer measures atmospheric pressure.

Humidity. This term is used to express the amount of water vapor in the air. Humidity is usually measured by the change in length of hygrometric substances giving relative humidity.

Wind Velocity. This describes the speed and direction of the motion of the air. A knot is a measure of speed used at sea by sailors. It is equal to one nautical mile per hour. A nautical mile is approximately 2 kilometers.

Condensation. Water vapor may condense into liquid or solid particles. Liquid is precipitation (rain) and solid gives cloud cover.

Radiation. Solar radiation refers to the number of hours of bright sunshine per day. Both solar and terrestrial are measurable by total radiation receivers.

Visibility. This is defined as the maximum distance an object can be distinguished against the background sky.

Observations of current temperatures, humidity, wind, pressure, and highest and lowest temperatures are usually transmitted by commercial radio and television systems, telephones, recording systems, and NOAA (National Oceanographic and Atmospheric Agency) Weather Radios for the localities they serve.

Data such as the previous day's highest and lowest temperatures and precipitation amounts are generally carried in newspapers for both the local areas and other cities. Many papers carry foreign reports. Television and radio weather programs sometimes carry selected data, primarily for U.S. cities.

Records of past weather, which also are compiled and analyzed to describe the climate on a local, regional, or worldwide basis, are maintained by NOAA's Environmental Data and Information Service. The Weekly Series of Daily Weather is another source of past weather data. It contains daily charts of surface weather patterns, upper wind patterns, high and low temperatures, and 24-hour precipitation across the United States for each week.

PROCEDURE:

Weather is important to everyone. In many instances it controls what we can or cannot do on a particular day. It is therefore important to be able to read and interpret weather maps. This introduces students to the different weather map symbols.

1. Go over the "Symbols Used in Plotting Report," especially the sky coverage. Students will have to interpret the cloud cover of both maps from the satellite and then transfer the information onto a blank map. Make sure that students understand the symbols.
     
   Precipitation refers to the way water is precipitating. Fog is low clouds. Snow is crystallized water. Rain is liquid water. Thunderstorms can refer to severe rain, including hail. Drizzle refers to light rain, while showers are a steady downpour of rain.  
     
   Wind speed and direction shows the direction of where the wind in coming from. The direction can be determined by comparing the line to north. So if the direction is south to north, you would refer to the wind as coming from the south. The speed of the wind is measured in knots which is a nautical term that is measured as 1.852 km per hour.
     
   Sky coverage refers to the amount of clouds in the sky. This may be suggestive if you are looking a satellite photo or you are on the ground looking up.
     
   Types of clouds refers to the clouds present at different elevations and the form they are taking.
     
   Fronts and pressure systems refer to centers of high or low pressure system. The different fronts include a cold front, warm front, stationary front, and occluded front. A cold front is when the leading edge of air is colder air replacing warmer air. A warm front is when the leading air mass is warm air that is replacing cooler air. A stationary front is when the front is stalled or not moving. An occluded front is when a cold front catches up to a warm front.
     
2. Use the worksheet for students to draw the symbols and to describe what each symbol means.
     
3. Use a local weather map to see if students can interpret the symbols found on them. Remember that sometimes the symbols may be a little different.

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