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    Using the Synoptic Code for the Prediction of Weather
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    Synoptic Code Experiments

    This experiment is courtesy of 

    Using the Synoptic Code for the Prediction of Weather


    M. Christopher Marchese
    Science Department Chairman
    Northeast Catholic High School
    Philadelphia, PA

    Andrew Batzell
    Rohm and Haas Scientist

    Lisa McNamara
    Rohm and Haas Scientist

    John Halligan
    Rohm and Haas Scientist

    Grade Level:

    9 through 12, College



    Earth and Space Science



    Upon completion of this lesson, the students will be able to:

    1. interpret the synoptic code

    2. construct a thermoscreen, with anemometer

    3. identify different types of clouds

    4. understand and read the barometric pressure

    5. construct a psychrometer to measure relative humidity

    6. understand what causes different types of weather

    7. coordinate their work with three different sites

    8. decode synoptic weather data via information sent by E-mail

    9. predict weather patterns as they apply to fronts, precipitation, etc.



    Because of the nature of this experiment, all students must be able to use the scientific method for the purpose of formulating a hypothesis on weather. This is very similar to the process by which television meteorologists study and predict weather forecasts over a five-day period.

    There are a number of disciplines needed to complete this experiment. Therefore, students should have full understanding of temperature, pressure, wind speeds, weather types, and humidity. The students after learning the different principles of meteorology, will apply this knowledge to the synoptic code.

    Every night when we watch our local news, besides sports and headlines, the most popular part of the broadcast deals with "what is the weather forecast?" Have you ever though about how weather is predicted, or why today it is 89 degrees and tomorrow it is going to be 81 degrees? With today's technology, the average human has an idea of this process. However, in the past, there were many different types of equipment and techniques used to determine weather patterns.

    Radar has been important in measuring weather since World War II. Meteorological radar equipment is used for observing precipitation, clouds and other atmospheric phenomena. Rockets have been used in exploration and the study of atmospheric structure. And with the birth of sophisticated technology, meteorological satellites are in orbit around the earth. These satellites measure infrared and visible radiance to provide routine observations of weather conditions in the lower atmosphere. At any given time, there are as many as eight to ten satellites in orbit. These satellites have the ability to construct images as they pertain to clouds, atmospheric water vapor, estimated atmospheric, land, and water temperatures. They are also used for forecasting of severe types of weather, such as, thunderstorms and hurricanes. With the help of computer technology, these satellites are able the predict movements of weather systems and fronts, which help in the routing of airplane and ship traffic.

    The synoptic code is a branch study of meteorology that combines the knowledge of atmospheric conditions with weather. The purpose of the synoptic code is for the quick interpretation of weather at a given station. The method of forecasting, also known as the synoptic method comprises data of atmospheric states, at different locations all at the same time. The network of stations are usually spread out at intervals of 10km.With hourly observation, synoptic sites around the world have the ability to construct maps, which show air masses and frontal locations. For the purpose of this experiment, students will be interpreting present weather, past weather, low, medium, and high cloud types and pressure characteristics. The information will be placed in code at each school's site and transmitted to a home base via the Internet for analysis.


    Prelaboratory Instruction:

    Air Pressure:

    Air pressure is directly proportional to the density of air at any point on the earth's surface. There are many different factors that affect the pressure of the earth's atmosphere. They are temperature, water vapor, and elevation. Think about playing baseball for the Colorado Rockies or the Florida Marlins. Which home field is more susceptible to homeruns? If you answered the Rockies, you are right. Air is much thinner at higher altitudes. Therefore, air pressure is not as great. The device used to calculate air pressure is called a barometer.



    Winds are formed by movement of air from one place to another. They are caused by differences in air pressure and from unequal temperatures in the atmosphere. There are two major types of winds. The global and the local winds. Local winds are the normal breezes we experience at the shore or while sitting on a park bench. There are two major types of breezes, named from their origin. A wind coming from the sea is called a sea breeze, and the wind coming from land is called a land breeze. Global winds are seen by specific patterns. (See below). There are doldrums, tradewinds, westerlies, and easterlies. A wind that is commonly seen on weather channels is the jet stream. This is a circulation of high-speed winds that dictate weather fronts. Airplanes feed off the jet stream for increasing jet speed when flying from west to east. Wind is measured by an anemometer. This device is calculates wind speed in meters per hour. One knot is equal to 1850 meters per hour or approximately 1.166 miles per hour.


    Relative Humidity and Clouds:

    Humidity is defined as moisture in the air. Air has the ability to hold water vapor. Depending on temperature, high relative humidity may be unbearable. Humidity is calculated by using a psychrometer. This device has two thermometers attached to it. One wet bulb and one dry bulb. Based on relative moisture in the air, the wet bulb reading can be much lower than the dry bulb. Scientists, using a chart, like the one below can calculate the relative humidity in the air. This calculation is based upon the difference in temperature of the wet versus the dry bulb.

    Because of these phenomena, clouds form. Clouds are composed of moisture held in the air. When moisture condenses clouds form. There are many different types of clouds. These clouds are structurally different based on the altitude where they exist. In times of complete atmospheric saturation, clouds return rain, sleet, snow, or hail to the earth's surface. The type of water returned to the surface depends solely upon atmospheric temperature and surface temperature.



    Temperature is determined by the amount of heat in the air. The primary source of heat is the sun. What causes different temperatures on the earth's surface? The angle at which the sun's rays strikes the surface of the Earth. If you looked at a typical drawing of the planet, you will notice its shape to be almost spherical. At the equatorial region of the earth, the sun's rays have the most direct path of incidence, as compared to the polar regions. Therefore, it makes sense that the air temperatures of land masses located closer to the equatorial regions are warmer.


    By combining the knowledge of the following, students will have the ability to predict and give weather forecasts. It all starts with the construction of the thermoscreen


    Preparing the Thermoscreen:

    The students working together as a class will first construct the thermoscreen. Each group of students will have a particular area to work on for the construction of the thermoscreen. The idea of the experiment is for this thermoscreen to be placed at a site away from the influence of the school building. Temperature, wind speed, relative humidity, barometric pressure, cloud coverage, wind direction, and precipitation. Based on hourly observations, the students will be able to take the observed information and interpret it by using meteorological symbols and synoptic code.



    psychrometer--wet and dry bulb
    rain gauge
    lattice work



    4 @ 6' 2 x 4
    12 @ 3' 2 x 4
    8 @ 2 x 2 x 4 ‘
    1 @ 3/3 x 3/3 x �' plywood
    1 @ 2/10 x 2/10 x �"
    2 sheets 4 x 8 plastic latticedrywall screws
    plywood door hinges
    latch workings


    Preparing Students for Synoptic Interpretation:

    Because the synoptic code is detailed and lengthily, students will be given the code symbols and numbers. Typically only one two-digit code is used for the observation of present weather. Numbers 20 through 29 is weather observed within the past hour.


    Figure 1. Synoptic Codes

    Present Weather

    00 No cloud development observed
    01-03 Cloud development or dissipation observed
    04 Visibility reduced by smoke
    05-06 Haze
    07-08 Dust or sand whirl
    09 Duststorm or sandstorm within site
    10 Mist
    11-12 Shallow fog or ice fog
    13 Lightning
    14-16 Precipitation in sight, not at station
    17 Thunder
    20-29 Weather in past hour
    20 Drizzle
    21 Rain
    22 Snow
    23 Rain and snow
    24 Freezing drizzle or rain
    25 Rain shower
    26 Snow shower
    27 Hail shower
    28 Fog
    29 Thunderstorms
    30-35 Dust or sandstorm
    36-39 Drifting snow
    40-47 Fog
    47-49 Freezing fog
    50-59 Drizzle
    60-69 Rain
    70-79 Snow
    80-90 Showers
    91-99 Thunderstorms


    Past Weather

    Past weather is defined as weather occurring in the hours of 00, 03, 06, 09, 12, 15, 18, 21 UTC. This information is calculated over a time span of three hours.

    0-2 Cloud cover
    3 Sandstorm, duststorm or blowing snow
    4 Fog, ice fog or thick haze
    5 Drizzle
    6 Rain
    7 Snow
    8 Showers
    9 Thunderstorms



    Low Cloud Type

    0 No stratocumulus, Stratus, Cumulus or Cumulonimbus
    1 Cumulus humilis or Cumulus fractus
    2 Cumulus mediocris or congestus
    3 Cumulonimbus calvus
    4 Stratocumulus cumulogenitus
    5 Stratocumulus
    6 Stratus nebulosus or Stratus fractus
    7 Stratus fractus or Cumulus fractus
    8 Cumulus and Stratocumulus
    9 Cumulonimbus capillatus
    * Sky obscured


    Medium Cloud Type

    0 No Altocumulus, Altostratus or Nimbostratus
    1 Altostratus translucidus
    2 Altostratus opacus or Nimbostratus
    3 Altocumulus transludicus
    4 Lenticular Altocumulus translucidus
    5 Thickening Altocumulus translucidus
    6 Altocumulus cumulgenitus
    7 Altocumulus and Altostratus or Nimbostratus
    8 Altocumulus castellanus or floccus
    9 Altocumulus of a chaotic sky
    * Sky obscured, often by lower cloud layer


    High Cloud Type

    0 No Cirrus, Cirrocumulus or Cirrostratus
    1 Cirrus fibratus or uncinus
    2 Cirrus spussatus or Cirrus castellanus or floccus
    3 Cirrus spisatus cumulonimbogenitus
    4 Thickening Cirrus uncinus or fibratus
    5 Low, thickening Cirrus and Cirrostratus
    6 High, thickening Cirrus and Cirrostratus
    7 Cirrostratus covering the whole sky
    8 Cirrostratus partially covering the sky
    9 Cirrocumulus
    * Sky obscured, often by lower cloud layers


    Barometric Pressure Characteristic

    Pressure the same or higher than 3 hours ago
    0 - Increasing, then decreasing

    Pressure now higher than 3 hours ago
    1 - Increasing, then steady; or increasing, then increasing more slowly.
    2 - Increasing.
    3 - Steady or decreasing, then increasing; or increasing, then increasing more rapidly.

    Pressure the same as 3 hours ago
    4 - Steady

    Pressure the same or lower than 3 hours ago
    5 - Decreasing, the increasing

    Pressure now lower than 3 hours ago
    6 - Decreasing, then steady; or decreasing, then decreasing more slowly
    7 - Decreasing

    Steady or increasing, then decreasing; or decreasing, then decreasing more rapidly



    At 8 am EST, your information site received two transmissions. One 30 miles and one 60 miles west of your station. Decode the following information, remember, the weather at your station is not comparable to the information just received. Make a prediction on weather that will be arriving in your area soon.








    Students will obtain synoptic codes from other schools for the purpose of predicting the weather at the home base. Ideal distances of other stations are approximately 25 to 30 miles in radius west of the home base. The notion is to receive synoptic codes from the following stations, and for the students to predict the weather, similar to meteorologists, without the computer technology. This is the data table they will use.




    Angular Surface Temperature: Is it all in the tilt?


    M. Christopher Marchese
    Science Department Chairman
    Northeast Catholic High School
    Philadelphia, PA

    Andrew Batzell
    Rohm and Haas Scientist

    Lisa McNamara
    Rohm and Haas Scientist

    John Halligan
    Rohm and Haas Scientist


    Grade Level:

    9 through 12, College



    Earth and Space Science, Chemistry and Physics



    Upon completion of this lesson, the students will be able to:

    1. construct a light board.

    2. understand the concepts of basic electricity.

    3. measure and observe temperature changes of different surfaces over time.

    4. understand the concept of radiant pathway.



    This experiment demonstrates relative temperature change as it pertains to different surfaces. Temperature is defined as the heat in the air. In order to determine the relative temperature, the students will isolate four different types of surfaces common on the earth's surface. Four equal watt bulbs are to be suspended over each container. At any given time, the students can switch the degree to which the light is hitting the surface, by rotating the light board on its axis. The ideal temperature angles are 180 degrees and 45 degree. This creates a model to which the sunlight hits the Earth at the equator and the poles. Students will measure and plot and graph the change in temperature over the change in time.


    Laboratory Preparation:



    3 2'x6' Wood Boards
    2 Plastic Protractors
    4 Porcelain Light Sockets
    4 100-watt light bulbs
    4 plastic buckets
    4 thermometers



    The midpoint of your light board must be found; mark this area with a straight line. Spread out the four light sockets, so that when the buckets are placed below the lights, the light is directly in the center of the bucket. Run the wire throughout each socket, then mount into the light board by screwing the socket into the wood. Repeat this step three more times. The other two boards are used as support legs. Drill a hole through the top center of each leg. Place washers in between the lightboard and its supporting legs. Fasten metal supports to the bottom for further reinforcement. The two protractors are positioned on either side of the lightboard, with the lightboard at a 180 degree angle. Mark the boards for both 180 and 45 degrees.


    This experiment will study the range in temperature of different surfaces over time. This will give the relative temperature change of all four surfaces. Grass, asphalt, water and sand at 24 hour time periods, over a two-day period. These four substances were chosen as representatives of common surfaces in our world today. There are many questions which need to be asked before performing this experiment. What effect does color and density have on the change in temperature? Does changing the angle of the light source create just as much temperature change as a direct hit? Brainstorm with your class before performing the experiment. Your students may have a number of good ideas.

    Students will construct a hypothesis for both the 180 and 45 degree angle. Observe and calculate data over a two-day time span. Compare and analyze results by group discussion.

    At 180 Degrees


    At 45 Degrees


    Why? Was your hypothesis true?

    Other related surfaces which can be tested.

    - concrete, gravel, clay, and Astroturf

    This experiment is courtesy of 

    My Dog Kelly

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    Last updated: June 2013
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