Weather mapping and analysis (36 points)
Examine the Surface Observation Map to address the following questions. This map shows station models depicting weather data across the United States. Be sure to use the Weather Map Symbols data chart at the end of the lab to help as needed.
1. Locate the station model in southeastern Iowa. Fill in the weather variables listed below that this part of the country is experiencing. Be sure to label units on any numbered variable.
temperature_______________ dew point temperature_______________
wind direction_______________ wind speed_______________
sky coverage_______________ current weather_______________________________
pressure_______________ pressure change over the last three hours_______________
2. Locate the station model in southern Texas. Fill in the weather variables listed below that this part of the country is experiencing. Be sure to label units on any numbered variable.
temperature_______________ dew point temperature_______________
wind direction_______________ wind speed_______________
sky coverage_______________ current weather_______________________________
pressure_______________ pressure change over the last three hours_______________
Isolines can be used to show patterns of many weather variables. Isolines are drawn using the same rules that apply to contour lines. An isotherm is a line of equal temperature. An isobar is a line of equal pressure.
3. Using a colored pencil, draw isotherms across Figure 1 with a 10°F interval. Begin with a line valued at 25°F. Label each line with its correct temperature. You may want to first draw the isotherms with a regular pencil that can easily be erased and then trace over them with a colored pencil or marker once you are confident in the locations. Indicate the color used for the isotherms by filling in the box here.
4a. Where are the warmest temperatures?
b. Where are the coldest temperatures?
5. What is the maximum temperature range present across this United States on this date?
6a. Circle three states from the list below that have the greatest temperature gradient across the state.
Washington California Wyoming Texas Kansas Minnesota
Arkansas Florida Kentucky South Carolina Pennsylvania Maine
b. How did you determine the states you selected above?
7a. Where are the highest dew points in the country? Why are the water vapor levels high in this part of the country?
b. Where are the lowest dew points in the country? Why are the water vapor levels low in this part of the country?
8a. What is the dominant wind direction across the central part of the country (from Minnesota through northern Texas)?
b. What is the dominant wind direction in the southeastern part of the country?
9. Label a location on Figure 1 where a continental polar (cP) air mass exists.
10. Label a location on Figure 1 where a maritime tropical (mT) air mass exists.
11. Cold fronts are locations where a colder, drier air mass (continental polar) pushes into a warmer, moister air mass (maritime tropical). Use the temperature, dew point, and wind directions on the map’s station models to locate and draw the position of the cold front on Figure 1.
12. Based on the map, will temperatures likely become warmer or colder than they currently are in central Mississippi and Alabama?
13. Based on the map, will dew points likely become higher or lower than they currently are in central Mississippi and Alabama?
14. Using a colored pencil, draw isobars using a 4 mb interval on Figure 2. Label each line with its correct pressure. Please note, some isobars will form enclosed circles in this case. Indicate the color used for the isobars by filling in the box here.
15. On Figure 2, label the high pressure center with an H. Label the low pressure center with an L.
16a. Which way are the winds rotating around the central high pressure system?
clockwise counterclockwise
b. Which way are the winds rotating around the central low pressure system?
clockwise counterclockwise
17. High pressure tends to produce mostly clear, sunny skies with lack of precipitation. While low pressure tends to produce cloudy conditions with potential precipitation. Do the data in this example support this conclusion?
18. Shade in all regions of the country with winds greater than or equal to 15 knots on Figure 2.
19. Differences in temperature cause differences in pressure. Differences in pressure cause wind. Thus, you might expect that areas with a high temperature gradient to have higher wind speeds. Do the data in this example support this conclusion?