Student Pages - Lesson 5 - Activity 5: Warm and Cold Fronts
Low pressure systems generally create cloudy, stormy weather and high pressure areas generally create fair weather. They also produce winds that rotate in opposite directions. In the Northern Hemisphere, low pressure systems always create winds that move counterclockwise. The high pressure systems always create winds that move clockwise. Winds around high pressure systems transport warm air masses from the south and winds around low pressure systems transport cold air masses from the north. It is this transportation of air masses that creates fronts.
Fronts are lines that denote the leading edge of a dramatic change in air mass or air temperature. The leading edge of the air mass travels forward along the weather front. When we observe an approaching front, we notice that the temperatures and air behind that front may be very different from the air and temperatures in front of it. Fronts lift and cool the air, which creates clouds and precipitation. If the air rotation is counterclockwise around a low pressure system, it will bring warm air from the south in front of the low and will bring cool air from the north behind it.
A warm front is shown on a weather map as a red line with rounded bumps. The round bumps indicate the direction that the warm front is moving.
On the other hand, a cold front is shown on a weather map as a blue line with triangles. The triangles indicate the direction that the cold front is moving. If the low pressure system did not produce counterclockwise wind circulation, there would not be movement of air masses and thus, no fronts.
Now that you understand fronts, use the internet to collect data for the 13 weather stations. Use the link below to gather real-time weather data for highs and lows for the 13 weather stations.
- http://weather.unisys.com/surface/meteogram/index.html
- http://weather.unisys.com/surface/meteogram/details.html
- http://www.srh.noaa.gov/jetstream/synoptic/wxmaps.htm Review of symbols and their meanings.
- Make sure you use the appropriate symbols for cold and warm fronts and place the symbols on your weather map and into your spread sheet. Make sure you gather data for all 13 cities.
- Find the two warmest stations and draw a line between them and label them WARM on you weather map.
- Find the two coldest stations and draw a line between them and label them COLD on you weather map.
2. Discuss your results with your group. Be prepared to share your report and your flipbook with the class.
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