Initial Publication Date: July 5, 2011

Climatology Basics

Part C: Local Weather Stories

As you learned in the previous labs, multiple factors work together to create the weather in a given location and time period. Most people probably haven't thought much about how fast, or in which direction, weather systems travel, nor how quickly the weather can change in a single day or week. In this lab, you will see how variable weekly weather can be, and you will consider the factors that make it so changeable.

You will also download and analyze temperature and precipitation patterns for one city over a number of years and see how climate patterns emerge from many years worth of weather data.

When we observe weather, we usually report temperature, precipitation, cloudiness, humidity, air pressure, wind speed, and direction. Weather observations are made by many systems, both from the ground and from above. These systems include: automated instruments, satellites, trained professional observers, as well as volunteers. If you'd like to become a volunteer weather watcher you can join the CoCoRaHS network.


Checking In

Begin the lab with this question: What is weather, and how does it differ from climate? Try your hand at using what you have learned so far in this module to sort out weather from climate. Choose one of the options listed here, either download and print the strips (below) or work with the interactive weather and climate sentence page.

  • Download and print the following sentence strips.
  • Cut apart the sentence strips.
  • Sort them into two groups: weather or climate. When you are done sorting, write out and add two more statements of your own to each set.

Track a storm system

Get a feel for the rate at which typical weather systems travel over a week's time by viewing a slide show of one week's weather. Examples of these systems are shown on the weather map, upper-right, as blue high (H) and red low (L) pressure regions, and their related frontal zones. Play the entire slideshow, below, see all the slides. Then play it again one slide at a time and examine it more closely. Choose one H (high) or L (low), or a front (blue or red lines), and follow the high or low with your pencil tip as it moves across the map, through space and time. Note: the slide show can be played full screen mode.

 
weather tracking ppt
Click to view

In this exercise, you will get a sense of how fast storm systems move across the contiguous (lower 48) United States, by recording and drawing the storm tracks of the two weather systems shown in the slide show above.

  1. Print out a blank outline map of the United States. (shown right) 
    Blank Map3
    Click the image to enlarge the map to full size and then download, save, and print the map.
  2. Using the printed maps from the link below or the online maps in the animation above, locate the first map in the series. Note and record the date and time of this map.
  3. Observe the location of the first low pressure center in the Seattle, Washington area on March 30, 2012.
  4. Record its location on the blank U.S. map by drawing a L on the blank map and circling it.
  • Advance to the next map image, March 31, 2012. Note the location of the low, now located near northern Idaho. Record this new on your blank map.
  • Advance to the 3rd map image. The low pressure is now over Montana. Again, record the location on your blank map.
  • Repeat this procedure for the next several map images, following one storm as it travels across the country, and eventually heads out across the Atlantic Ocean.
  • Draw a black line connecting the location of the low across the map.
  • Rewind the map images to April 2nd, 2012, and track a second storm. Either start with the one off the coast of Washington, or the one located over South Dakota.
  • When you are done tracking the storm, answer the Stop and Think questions listed below.

Stop and Think

1. Which day (date) did the L pressure move off the Atlantic coast? 

2. How many days did it take for the storm to travel across the country? 

3. Given the distance the storm traveled as approximately 2700 miles (4350 kilometers), what was the average rate of travel of the storm? Express your answer in miles (or kilometers) per day.

 

Discuss

Talking about the Weather 
Some areas have weather patterns that are more variable than others. You may have heard the adage: "If you don't like the weather in Vermont (or some other place...), just wait five minutes." How fast does the weather change in your hometown or neighborhood? 

Recall the regional climate drivers that you studied in Labs 3A and 3B. Which of these factors contributed to the movement of this storm system across the country? Choose a location on the storm track and use your knowledge to write out a script that could be used by a TV meteorologist to describe the weather patterns shown in the series of images. Share your weather story with your lab team or class.

 

Use weather data to discover climate patterns

In this next activity, you will use the NOAA's National Climatic Data Center (NCDC) records to explore temperature and precipitation data for a selected area. You will begin by selecting one single year's worth of data to view, and then you will expand the graph to display data from an extended period of time—up to 120 years. By exploring this historical dataset, you will learn how daily weather patterns vary over a typical year and you will get a sense of how climatologists use long-term records to arrive at a definition of "normal" temperature and precipitation.

When you have investigated these concepts, you will apply your skills by using the NCDC site to inform your answer to the question: "What will I wear to my cousin's wedding in May?"

When we think of weather we often only think of today, this week or this month. However, if you step back and look at a large collection of weather data it is possible to use the daily records to visualize the climate. The NCDC archives many variables of weather and climate data, summarizing the data in both monthly and daily time frames, making many types of research possible.

The daily data recorded at these NCDC stations includes observations of: maximum and minimum temperature, precipitation amount, snowfall amount, and snow depth. Monthly data includes mean, maximum, and minimum temperature and total precipitation.

The data you will use in this activity is available at the following website. Access the National Climatic Data Center's Divisional Data Interface ( This site may be offline. ) (link will open in a new window) to begin your investigation.

Static Graph Interface

  • On the Data Retrieval page, click the "State" tab first and choose Montana, then click the "Division" tab.
  • Select the Eastern division or region of the state. Your teacher may assign another place for you to investigate.
  • Use the dropdown menus to select Starting and Ending dates that span the last full calendar year (January through December).
  • Click the Static Graphs radio button and select Temperature from the pull-down menu.
  • Next to the word "Show," make sure that "All Months" is showing.
  • Click Submit.


  1. On the graph that appears, read the axes labels and the legend to interpret what it means. Does this graph provide you with enough information to know what to wear to the wedding?
  2. Use your browser's back button to go back to the Data Retrieval Page. Use the same selections as before, except for changing the Start Date two years earlier so that you request the last 3 years of temperature data.
  3. On the three-year temperature graph, check and record the values reported for each May.
  4. Go back to the Data Retrieval Page again. This time, request a static graph of precipitation for the last full year (January to December). Read the axes to interpret the graph. Look for patterns that indicate whether the region you are studying appears to have a rainy season or a dry season.
  5. Generate another graph to show three years of precipitation data. 

Checking In

What new patterns emerge in the plotted data when you add more years to the graph?

  1. Go back to the Data Retrieval Page again. In the drop-down box next to the word Show, highlight "May" and set the Starting and Ending Dates to request May temperatures for the last 10 years. 

    Do a Reality Check... Look to see if the values seem realistic. If they don't, try setting the month of the Starting Date to the same date as you are requesting. For example, to request May temperatures, set the month of the Start Date to 05.
  2. Explore the data by generating several more graphs, requesting temperatures and precipitation levels for various months over the full range of the data.
  3. For more weather variables, such as wind speed and barometric pressure, access the Weather Underground historical data website. Again, input your city, and date range of choice in order to observe daily, weekly, monthly, or custom date range data outputs.

Stop and Think

4. How do the long-term graphs of weather data compare to the original (single year) graph? Which type of graph is a better representation of typical temperature and precipitation for a station?

5. Your cousin in Hastings, Nebraska (NE) has invited you to her outdoor wedding in early May. What will you wear? What is the likelihood that you will you need a sweater or jacket? Might it be over 100° in which case you better bring shorts! Is it likely that it will it rain? Use the NCDC and Weather Underground sites to investigate historical Nebraska temperature and precipitation data in order to answer this question. Explain your clothing selection and your procedure for arriving at this decision.

Optional Extensions