Air Masses and Fronts

Ryan Keser
Type Category
Instructional Materials
Activity , Lesson/Lesson Plan
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



Air Masses and Fronts is a detailed lesson plan from Better Lesson in which students study the movement of air masses across North America and how their interactions cause weather to change. The lesson begins with a split tank demonstration to illustrate the roles of temperature and density in the movement of fluids. Students then investigate relationships between cloud cover, precipitation, temperature, and fronts utilizing a series of simplified weather maps. The lesson depends on prior knowledge of convection. Teachers may need to review this concept so students can successfully describe the movement of fronts and the resulting weather patterns.  

The lesson follows the 5E Lesson Model. Several resources are provided, including lesson plans, background information for the teacher and a student activity sheet. The author shows video clips of students working in groups on the activity and the instructor asking probing questions.

A link to the University of Illinois Earth's Atmosphere Resource for additional information about weather doesn't work. Teachers may want to use instead.

The author states this activity will take about 70 minutes.  The teacher may need to purchase a split tank and food coloring to do the demonstration. They may also need to make color copies of the maps in the lesson.

Intended Audience

Educational Level
  • Grade 6
  • Grade 7
  • Grade 8
  • Middle School
Access Restrictions

Free access with user action - The right to view and/or download material without financial barriers but users are required to register or experience some other low-barrier to use.

Performance Expectations

MS-ESS2-5 Collect data to provide evidence for how the motions and complex interactions of air masses results in changes in weather conditions.

Clarification Statement: Emphasis is on how air masses flow from regions of high pressure to low pressure, causing weather (defined by temperature, pressure, humidity, precipitation, and wind) at a fixed location to change over time, and how sudden changes in weather can result when different air masses collide. Emphasis is on how weather can be predicted within probabilistic ranges. Examples of data can be provided to students (such as weather maps, diagrams, and visualizations) or obtained through laboratory experiments (such as with condensation).

Assessment Boundary: Assessment does not include recalling the names of cloud types or weather symbols used on weather maps or the reported diagrams from weather stations.

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
Students observe convection when bodies of fluids of differing densities meet in the split tank demonstration. Teachers should consider using red food coloring instead of yellow for the warm water in the split demo tank so it is more easily associated with a warm front. They should also make sure that students understand that air in the atmosphere behaves as water does in the demo tank, since both are fluids. In the Explore section of Air Masses and Fronts, students look for patterns and evidence of how the interactions of air masses result in changes in weather conditions as they utilize maps of fronts, cloud cover, precipitation, and temperature in Step 4. The speed at which weather changes is addressed when they study the movement of cold fronts versus warm fronts. In order to collect data, the teacher should provide local weather maps as suggested in Step 6 and task students with gathering evidence of how fronts, as the leading edge of air masses, result in changing weather conditions in their area. Studying the maps and recording weather conditions over a period of time would enhance their understanding of the relationship and the probability of predicting the weather accurately. The flow of air masses from regions of high pressure to low would have to be addressed in another lesson such as

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
Students apply scientific principles of density and relative humidity to investigate the creation, characteristics, and movement of air masses and associated fronts. They apply these principles to construct an explanation for different weather patterns.

Disciplinary Core Ideas

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
The lesson addresses portions of the Disciplinary Core Idea. Students relate the temperature and moisture content of various air masses to their source regions. For example, Maritime Tropical Air Masses form in the atmosphere over warm ocean waters at low latitudes. Regional geography is addressed when examining the regions in which air masses form. Students examine the movement of air masses and fronts throughout the lesson which shows atmospheric flow patterns. In order to more fully address the Disciplinary Core Idea, the teacher would need to specifically ask about the link between intensity of sunlight and air mass formation (polar versus tropical) as well as resulting weather – rain versus snow, for example. Teacher can address altitude and regional geography by using local maps as suggested in the Explore Section. The lesson is not designed to address climate, although the topic can be addressed in the discussion of air masses as their characteristics are indicators of climatic conditions. The impact of ice and landforms can also be addressed in a discussion of the characteristics of air masses, i.e. polar ice plays a role in polar air masses and landforms create continental air masses. The teacher will need to use other resources to address the interactions of living things. A lesson on the impact of population change on Earth’s oceans and landform such as may be used. The impact of latitude and landforms on oceanic flow patterns can be discussed using a map at

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
Students investigate the cause and effect relationship between air masses and the resulting weather phenomena. This relationship is the focus of the Explore - Explain section of the lesson.

Resource Quality

  • Alignment to the Dimensions of the NGSS: Grade-appropriate elements of the three dimensions work together to support students in making sense of weather phenomena. The lesson includes part of the complex Disciplinary Core Idea on weather and climate when students investigate how air masses and the resulting weather are influenced by sunlight and the ocean. They see how air masses vary with latitude (polar versus tropical) and local and regional geography (continental versus maritime). Students use the Crosscutting Concept of cause and effect and the Science and Engineering Practice of creating explanations when they examine the relationship between air masses and resulting weather phenomena.

  • Instructional Supports: The lesson engages students in a meaningful scenario of interpreting weather indicators much as meteorologists do in the real world. The purpose of the lesson is to make sense of weather phenomena and connect simple weather map symbols to associated weather patterns. In the Explore section, the author suggests that the teacher provide regional weather maps so students can connect the symbols on a weather map to their own experiences – to the weather outside their window. The Split Demo Tank is designed to provide students with a shared experience prior to studying the weather maps. The directions for this section are rather prescriptive. Teachers may want to use it as a time to garner interest in a phenomena and not tell students what is happening, instead referring back to that experience at later points in the lesson. The background information and answers provided are accurate and appropriate for middle school. Students have opportunities to express and represent their ideas while answering questions during discussions and while completing the worksheet. They are encouraged to justify their thinking as they interpret the maps in the Explore section. They have an opportunity to respond to peer and teacher feedback orally. Supports for differentiated instruction are not addressed.

  • Monitoring Student Progress: The lesson does provide a student worksheet in which they record their answers. Teachers can use this to assess student progress although no rubrics or scoring guidelines are provided to assist in interpreting student performance, in planning instruction or providing ongoing feedback to students. The worksheet is not aligned to the three dimensions in any way. No formative assessments are included. Students do use the Practice of constructing explanations and the Crosscutting Concept of cause and effect to make sense of weather phenomena. Methods, vocabulary, representations, and examples are accessible and unbiased for all students. Teachers may want to have students model the behavior of air particles when fronts meet and clouds are formed to better align the lesson with NGSS.

  • Quality of Technological Interactivity: No interactivity with technology is required, although the teacher will need Internet access to download the worksheet and show the videos.