Ms. Clark’s students have found success identifying patterns in precipitation, but she wonders how they think about the factors that affect those patterns. She is aware of many strategies for uncovering students’ thinking, but in this case, she decides to spend a class period having students make and discuss scientific claims about where in the state (and the related geographic features) the other stations are located based on their precipitation totals. Using information gathered through class discussion, Ms. Clark will select resources that will help students further their understanding the following day. 

Prior to disclosing the location of the station (i.e., in the mountains or coastal region), Ms. Clark reviews the data reports from each station with her students (e.g., to check for missing data). Once they determine they are working with complete data sets, Ms. Clark shares the total precipitation recorded by the two stations outside their region. Ms. Clark writes the two totals on the board: Station A: 22.24 inches and Station B: 18.20 inches and asks students what they notice about the two values. 

One student replies, “Both are more than ours! We measured less than 17 inches in the fall.” Another student adds, “One is only about an inch more, and the other is about 5 inches more!” Ms. Clark asks the students to write the two totals down and then record a claim about where in the state they think each station is located, providing a reason for why they think that.

After students share their ideas with a partner, Ms. Clark asks students to share with the class, and she makes a list of student ideas about each station. One student shared, “I think that the station that recorded 18.20 inches is close to us, because the total was similar to what our station recorded.” Under Station B, Ms. Clark adds “close to us” but then asks the class what should count as “close.” After discussion, the class decides on “50 miles or less.” 

Another student offers a claim about Station A, “I think that station is near the coast because they recorded over 22 inches, and that was probably because of hurricane season.” 

Ms. Clark’s class has generated and recorded several claims as the class period is coming to an end. Reviewing the lists of student ideas, Ms. Clark organizes these student ideas about factors that might explain the differences in rainfall as a record of what students know and understand, at that point, about the factors that account for differences in rainfall. She will use this information to begin instruction the next day. Knowing that Station A is actually located in the mountains (not on the coast as many students thought), Ms. Clark expects this revelation will surprise students. She gathers some topographic maps and resources related to “rain shadows” to help students understand how the other station’s location (east of the mountains) affects its precipitation. Additionally, to help students understand that being in close proximity doesn’t always mean similar precipitation, Ms. Clark downloads a small data set from a station very close to their school to emphasize that “rain doesn’t fall the same on all,” even if you are just a few miles apart.

After the students have examined the additional data, and after considering the factors that are believed to account for the differences in those data, the students and teacher compile a revised set of factors that students know and understand. The teacher can then call students’ attention to how this is similar to the way that science works: hypotheses are formed based on current scientific knowledge and that knowledge is revised and grown as new scientific evidence is acquired.

Additional information on using topographic maps can be found in the content resources.

As students compare their seasonal data with other stations’ data in different regions, there will be a strong focus on making sense of the data within the graphs. Refer to the Practice Overview in December for tips on Analyzing and Interpreting Data.

Why is it important to make sense of trends in weather data? 

The Next Generation Science Standards (NGSS Lead States, 2013) highlight crosscutting concepts (CCC) that identify connections across areas of science including patterns, cause and effect, and systems. As students begin to examine more data (e.g., more months, more regions, more seasons), they may start noticing trends in the data. Scientists use these trends to make predictions about water levels, amounts of rainfall/snowfall, drought conditions, and more. 

• Meteorologists use trends in data to make and verify their forecasts.
• Hydrologists use trends in data to examine water levels in streams, rivers, and reservoirs. 
• Water Management facilities use trends in data to manage the projected water demands of their customers. 
• Agribusiness monitors trends in weather data for crop development and yield. 
• Climatologists examine year-to-year precipitation trends as they review drought, severe weather, and overall climate models. 
• Trends in weather are valuable for recreation enthusiasts, from fishermen to kayakers to ski resorts, golf courses, and more. 

How can I help my students make sense of the trends in our weather data? 

Below are suggestions for students to communicate their sensemaking of trends in weather data for one of the scientists or others listed above (or another from the CoCoRaHS website: Who Uses CoCoRaHS Observations?). 

• Have students share one trend they have noticed in their data. Example: I see it has rained for four days straight, no less than 0.65 inches each day. That is a lot of rain in such a short amount of time. The ground is saturated. 

• Ask students to choose one of the scientists or others (recreation facilities, water management facility, etc.) that use the CoCoRaHS data observations. Example: I think a soccer field manager would be very interested in this trend because if it continues to rain, they may not get many soccer games in, which would affect their overall business. Also, if the teams do play, they will be running into a lot of puddles, mud, and wet ground where the ball won’t roll well, players might get injured, or the fields might get damaged. 

• Have students write a short podcast or weather forecast script to share with scientists or their classmates. Example podcast script: Good morning, and welcome to your daily weather trend report. Today we have disappointing news for all of our soccer fans out there. Unfortunately, with four days straight of rain and no end in sight…unless you can play in rain boots or umbrellas on your head…it looks like you might not get back out onto the soccer fields this week! The overall forecast indicates there might be some clearing in the skies, but our weather trend report suggests that due to the large amount of rain we’ve had for four days straight, the ground may be supersaturated for some time. If your team does decide to head on out there, be careful! Be prepared for kicking up more water than your ball, and know that your ball won’t roll for long after landing, so you will have to adjust your kick. You might be better off playing traveling soccer down in some fields in the Coastal Plains region of the state where they haven’t seen a drop of rain for a month! That’s all for our weather trends report today. Let’s hope there’s a dry spell in our forecast so you can get out to play ball without getting soaked or covered in mud!

To expand on the scientists that use trends in data provided above, a diverse list of faculty in the NC State Department of Civil, Construction, and Environmental Engineering can be found at this link, including a link to a scientist that specifically studies hydroclimatology.

• Rain Shadow: One side of a mountain has much more rainfall than the other side because the mountain casts a “shadow” on one side, keeping it much drier than the other side. Consider another location in relation to a large mountain range. For more support on this concept, consider the following resources: 
  • Wikipedia Definition
  • Rain Shadow Effect YouTube video
  • Why Asheville has a Rain Shadow YouTube video

• Proximity to water: Winds that blow off of a warm body of water tend to increase humidity and rainfall. Consider another location in relation to a large, warm body of water. 

By considering these geographic features, students will be better equipped to analyze, compare, and synthesize the data shared from another location.