Learner Outcomes

By completing this lesson, the learner will:

• observe polar weather patterns
• make generalizations/predictions about local weather from global observations
• interpret vertical sounding data
• create mathematical graphs and models describing relationships among atmospheric variables
• predict the development of a tropical storm through satellite imagery.

Exploration

Find several current GOES images or other recent satellite images of the Gulf of Alaska. What is the general direction and rotation of weather systems near Alaska? Convert image time (in Zulu or GMT) to local time. What is the duration between GOES images? How do you think polar weather affects your local weather?

Experiment

Keep track of events in the Gulf of Alaska by examining images from Unisys Weather, the University of Wyoming, or the University of Wisconsin-Madison. As soon as you notice the distinct comma shaped cloud mass indicating a developing low pressure cell and the associated fronts and cloud patterns, follow the progress of the storm. Each day analyze the upper level charts and examine the satellite images and make predictions for the following day; compare the previous day's prediction with the current day's reality. {Click here for a review on making weather observations, and click here for a review on weather forecasting and a weather forecasting contest}.

2. Make an analysis of weather variables and their relationship to local weather.

Locate the thermodynamic hodograph/skew-t plots for your city or the nearest city to you (interpretation help can be found here). Make graphs of pressure vs. elevation, temperature vs. elevation, wind direction vs. elevation, and humidity vs. elevation using a spreadsheet program.

3. Find a major cold front somewhere in the United States. Locate the vertical soundings for

• a locality above the cold front,
• a locality below the cold front,
• a locality above the warm front, and
• a locality below the warm front.
Plot pressure vs. elevation, temperature vs. elevation, wind direction vs. elevation, and humidity vs. elevation. Develop a model (derive a predictive formula, linear or non-linear regression) that fits these data (use a spreadsheet or graphing program). Plot the localities on a map showing positions of the fronts. Do your plots fit the characteristics of what you would expect for these localities? Why or why not? Use the model to predict sea level temperature and pressure. Compare these values with a map showing temperature and pressure; do your values match? Why or why not? Describe your results.

Extensions

Examine a satellite image which shows a well developed hurricane and a tropical storm to familiarize yourself with what these weather phenomena look like. Check out the archived material at Unisys Weather site for historical data and images on hurricanes. During the hurricane season (late summer to early winter) keep track of events in the central Atlantic Ocean and the Caribbean by examining images from The Weather Underground, or Unisys Weather site.

As soon as you notice the distinct comma shaped cloud mass indicating a developing tropical cyclonic storm and the associated cloud patterns, follow the progress of the storm. If it reaches a higher level of severity (for example, tropical depression to tropical storm, or tropical storm to hurricane,) examine the satellite images and make predictions of the pathway. For the following day; compare the previous day's prediction with the current day's position. You may want to look under hurricanes; at this site for the tracks taken by previous storms. If it turns out to be a major storm, keep track of all information presented in the media.