Teaching Notes
& Technical Tips
Grade Level
6-12

Subjects
Earth Science
Mathematics
Geography
Technology

NCTM Standards
Problem Solving
Communication
Reasoning
Connections
Number Relationships
Computation & Estimation
Algebra
Measurement

INVESTIGATION

What is the National Radar Summary map; what does it show?

OBJECTIVES

After completing this activity, you should be able to:

  • Describe the National Radar Summary map: explain how the map is prepared and what it shows. (Be sure to relate the local radarscope view to the National Radar Summary map.)
  • Locate areas of precipitation by interpreting a National Radar Summary map.
  • Determine the areas of most intense precipitation.
  • Track precipitation echoes as they move across the National Radar Summary map: observe changes over time; make predictions.
  • Explain how areas of precipitation relate to large-scale weather systems such as Highs, Lows, and fronts (by comparing the National Radar Summary map to a current surface weather map).
  • Explain how areas of precipitation relate to areas of cloud cover (by comparing the National Radar Summary map to a current infrared weather satellite image).

PROCEDURE
Technical Tip:
External links will open automatically in a second browser window; subsequent clicks on external links will replace the contents of the second window. This enables the user to keep both the activity and related graphics on the desktop.

Teaching Note:
Provide each student with a hardcopy of the activity Answer Sheet.

  1. Read the Introduction to Weather Radar. Alternate resource: Introduction to Remote Sensing (see "Doppler Radar").

  2. Download a current National Radar Summary map (or use a map provided by your instructor). Note: By clicking anywhere on the map, you can zoom in to a regional radar map showing a smaller area in greater detail.

  3. Answer the following activity questions. Base your answers upon your interpretation of the weather graphics that are hyperlinked within each question, as well as supplemental information presented in the sidebar (shown left). Record your answers on the National Radar Summary Activity Answer Sheet.

QUESTIONS
Conversion Factors:
mi = km x 0.621
km = mi x 1.609

Weather Calculators, courtesy National Weather Service, Sterling, VA. See "Wind Speed Conversions."

  1. Local Radar Imagery versus National Radar Summary map:
    1. What is the approximate maximum range of coverage for NWS local radars (in miles and kilometers)?
    2. Is there a single National Weather Service radar capable of scanning the entire United States for precipitation echoes?

You may need to convert the time from GMT (UTC) to Eastern Standard Time (EST) or Eastern Daylight Time (EDT). Refer to the time conversion table.
  1. What is the date and local time of the National Radar Summary map?
On the National Radar Summary map, the heights of storm cloud tops are shown in hundreds of feet, with the last two zeroes omitted. For example, 300 = 30,000 ft.
  1. Where is precipitation occurring?
    1. Using the following table of two-letter abbreviations for state names, cross-off all of the states in which precipitation is occurring. You may need to refer to a map of the United States (courtesy National Geographic Society) and/or a map of two-letter abbreviations for state names.

      Two-Letter Abbreviations - State Names
      AKALARAZCA COCTDEFLGA
      HIIAIDILIN KSKYLAMAMD
      MEMIMNMOMS MTNCNDNENH
      NJNMNVNYOH OKORPARISC
      SDTNTXUTVA VTWAWIWVWY

    2. According to the National Radar Summary map, is precipitation falling where you live?
    3. What is the maximum cloud top reported?
    4. What is the general relationship between precipitation intensity and the height of storm cloud tops?

  1. Using only the information provided on the National Radar Summary map, for those areas showing precipitation echoes, can you determine what type of precipitation is falling (e.g., rain, snow, thundershowers, etc.)?
Technique Hint:
Measure the distance that precipitation echoes move from the beginning to end of the animation.

Speed = Distance/Time

Example:
60 mi/6 hr = 10 mi/hr

Scale of the Map
Before you can measure distance on the map, you will need to determine the scale of the map. You may need to refer to a brief tutorial on determining fractional scale. To measure a real world distance to use to calculate the scale of the National Radar Summary map, you may need to refer to a map of the United States, courtesy National Geographic Society.

Conversion Factors:
Nautical Miles (knot)
mph = knot/0.87
knot = mph/1.15
kmph = knot/0.54
knot = kmph/1.85

  1. Do radar echoes change over time?

    Download a current USA radar map, courtesy WSI Corp. Intellicast. Follow the link to Start Looping (located at the top of the map), in order to display an animated GIF of the past two hours of national radar summaries. Note: By clicking anywhere on the USA radar map, you can zoom in to a regional radar map, that is also animated. Optional: Follow the link to Interactive Loop, featuring a button for a 12-hour loop.

    1. What is the direction (N, NE, E, SE, S, etc.) and speed of movement of precipitation echoes across the United States (in mi/hr or km/hr)?

      Hint: Verify your answer by comparing it with the arrows showing direction of cell movement and speed (in knots) on a current National Radar Summary map.

    2. According to the sequence of maps, make a precipitation forecast for your location. If precipitation is currently occurring, then predict how much longer the precipitation will occur. If precipitation is not currently occurring where you live, then predict when the next precipitation event might begin. Your forecast should be based (in part) upon the direction and speed at which observed precipitation echoes are moving (refer to Question 5a).
The USA radar map used in Questions 5 & 6 is a "value-added" product that utilizes surface weather observations to verify the type of precipitation observed by a national network of local weather radars.
  1. Compare the USA radar map to a current surface weather map. How do areas of precipitation relate to large-scale weather systems such as Highs, Lows, and fronts?
On black and white infrared weather satellite images, higher (colder) cloud tops appear white or shades of light gray. On enhanced infrared images, the highest (coldest) cloud tops appear as shades of dark gray to black embedded within areas of white; color-enhanced IR images often show the highest cloud tops as shades of yellow, orange, or red.
  1. Compare the USA radar map to a current infrared weather satellite image.
    1. Do all clouds produce precipitation?
    2. Can you infer the general relationship between the temperature of storm cloud tops (e.g., thunderstorm cells) and precipitation intensity?
Copyright © 1997-2008 by Walter Sanford. All rights reserved.
Weather Radar Activity | Comments/Suggestions?
Online Geoscience-Related Activities | Geosystems in FCPS