The frequency changes as the storm moves, so the speed of the storm can be calculated from how much the frequency changes. With Doppler technology, meteorologists can now track the paths of thunderstorms and potential tornadoes with much greater accuracy than in the past.
Weather Stations and Satellites
Automated weather stations are important in gathering weather data. These stations gather information without a human observer being present. A typical weather station is shown in Figure 28. It includes sensors that measure weather data such as temperature, precipitation, and wind speed and direction. The information collected is transmitted as radio signals to a weather center, where it can be displayed on a computer monitor.
Since the early 1960s, weather satellites have been placed in orbit around Earth to collect information about weather, including cloud cover, humidity, temperature, and wind speed. Meteorologists combine data from various weather stations and satellites to form a comprehensive view of a region's weather.
Figure 28 These scientists are setting up an automatic weather station on an island in the Bigourdan Fjord, Antarctica.
Data Analysis
Tracking the Weather
Meteorologists track weather data closely to help produce accurate short-term forecasts and to understand longer-term variations in weather. The table at the right provides the actual daily average temperature and daily precipitation for Minneapolis and St. Paul, Minnesota, for a seven-day period. Use the table and your knowledge of weather to answer the questions below.
Using Tables On which day was the average daily temperature highest? On which day was it lowest?
Calculating The average daily temperature on Day 7 was 11°C below normal. What is the normal temperature for that date?
Using Tables What were the maximum and minimum average daily temperatures over the week? What was the temperature range?
November Weather
Day
1
2
3
4
5
6
7
Average Daily Temp. (°C)
−7
−7
−4
−4
−6
−5
−13
Daily Precip. (cm)
0
0
11
1
3
16
3
Inferring What was the total precipitation over the seven days? What was the likely form of this precipitation? (Hint: Recall that the freezing point of water is 0°C.)
Predicting What type of front most likely passed through the region on Day 6 or Day 7? Predict the weather conditions that followed.
Making Generalizations Suppose you were visiting Minneapolis during this period. Describe how the weather changed during your visit.
Table of Contents