Meteorology Lab Activity: Interpreting Surface Observation Symbols Introduction: Routine surface meteorological observations are represented on weather maps by a standard notation of symbols and numbers. In order to correctly interpret the data, it is important to understand what types of data the different numbers and symbols represent. This skill is not only important for reporting weather conditions for a given station, but also for determining the positions of significant meteorological features like fronts, cyclones and anticyclones. The purpose of this activity is to introduce these reporting symbols and how to extract information about temperature, dew point temperature, wind speed and direction, cloud cover, pressure and current weather. Key words throughout this activity link directly to helper resources that provide useful information for answering the questions. Part I - Components of the Observation Symbol: 1. Fill in the blanks of the diagram to indicate what type of meteorological data is represented by each location. You may look in the appendix at the end of this lab for help.
2. Give the wind direction and wind speed in knots for the following three symbols. 3. Complete the following tables by reading the information from each weather symbol below.
Part II - Reporting on Weather Conditions: Use the map of surface observations to answer the following questions. Example: #1: Denver, CO Light Rain, 30 F, Dew point 28 F, Pressure 1007.4 mb, Skies Overcast, Wind 23-27 knots from the Northeast 1) What is the temperature in Des Moines, Iowa? 2) What is the dew point temperature in Phoenix, Arizona? 3) What is the pressure in Dallas, Texas? 4) What is the report of cloud cover in Chicago, Illinois? 5) What is the report of current weather (weather symbol) in Casper, Wyoming? 6) What is the speed and direction of the wind in Miami, Florida?
Part III - At Home Internet Activity Reporting Current Weather Conditions: 1) Now apply what you have learned to real-time weather data. Go to the www.wx.com* and type in the zip code for Muscatine, IA (52761). Construct a surface observation weather symbol recording weather data given. List the latest observations for temperature, dew point temperature, cloud cover, pressure, current weather, wind direction and speed. Then complete simillar diagram for the follow cities. Muscatine, IA Chicago, IL Seattle, WA Washington, D.C. * If www.wx.com is unavailable, try Weather Underground at www.wunderground.com.
Appendix Weather Symbols
Weather Station Model Explanation Temperature: The value highlighted in yellow located in the upper left corner is the temperature in degrees Fahrenheit. In this example, the reported temperature is 64 degrees. Weather Symbol: The weather symbol highlighted in yellow indicates the type of weather occurring at the time the observation is taken. In this case, fog was reported. If there were thunderstorms occurring when the observation was taken, then the symbol for thunderstorms would have appeared instead. Dew Point Temperature: The value highlighted in yellow located in the lower left corner is the dew point temperature in degrees Fahrenheit. In this example, the reported dew point temperature is 58 degrees.
Cloud Cover: The symbol highlighted in yellow indicates the amount of cloud cover observed at the time the observation is taken. In this case, broken clouds were reported. Here the sky is 75% cloud cover. Sea Level Pressure: The value highlighted in yellow located in the upper right corner represents the last three digits of the sea level pressure reading in millibars (mb) with the last number to the right of the decimal point. Here it is 027 which is 1002.7
Wind Barb: The symbol highlighted in yellow is known as a wind barb. The wind barb indicates wind direction and wind speed. Here the wind speed is 13-17 knot from the southeast. The wind barb might also indicate the rise and fall of the current pressure. If the flap is slanting upward from the wind barb the the current atmospheric pressure is rising. If the flag is slanting downward toward the wind barb the current atmospheric pressure is falling. If the flag is level the pressure is holding steady. This wind barb say the pressure is rising. Pressure Tendency Symbol Rising / Steady Falling \