Midlatitude Cyclones: scaffolding activity

Introduction:
A cyclone is an area of low pressure around which the winds flow counterclockwise in the northern hemisphere. Winds associated with midlatitude cyclones transport heat and moisture from the tropics to higher latitudes and these air masses typically clash in the middle latitudes, often producing clouds and precipitation. The purpose of this activity is to introduce the characteristics of cyclones, the associated air masses and fronts, and finally how to locate the center of a cyclone from wind observations. Key words throughout this activity link directly to helper resources that provide useful information for answering the questions.

Common Characteristics of Cyclones:
1) Complete the following sentence: A cyclone is also is known as a _______________________________.

2) How is the center of a cyclone labeled on a weather map?

3) Describe the weather conditions that typically accompany a cyclone.

4) Describe how a midlatitude cyclone appears on a satellite image.

Associated Air Masses and Fronts:
5) The diagram below depicts a model cyclone with associated fronts and air masses. Answer the following questions by labeling the diagram itself. You may label the diagram in one of two ways; 1) by printing out a copy of this activity and marking your answers directly onto the printout or 2) by saving the image into your favorite graphics software and modifying the image using that graphics package.

Circle the center of the cyclone
Label air mass #1 and air mass #2 (as was done for air mass #0)
Label the types of fronts represented by front #3 and front #4

6) Describe the general wind pattern associated with cyclones.

Storm Tracking:
7) For each of the following three surface maps, (Map #1, Map #2, and Map #3), use the wind barbs to determine the location of the cyclone center. Mark its position on the blank map for each map, using the correct symbol to represent the center of a cyclone. For each position, also indicate the date and time.

Map #1

Map #2

Map #3

8) What was the cyclone's general direction of movement?

9) In what state was the storm located in for map #1? What about maps #2 and #3?

Find the Current Cyclones:
10) To apply what you have learned to real-time weather data, go to the Weather Visualizer ( CoVis version | public version) and create a map of the latest surface observations. From this map, identify the position of any midlatitude cyclones that may be influencing the weather in the United States.

You may label the diagram in one of two ways; 1) by printing out a copy of this activity and marking your answers directly onto the printout or 2) by saving the image into your favorite graphics software and modifying the image using that graphics package. If the Weather Visualizer is too busy, here are additional web sites for accessing current weather data.

precipitation

Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

universal time coord