Name:______

ATOC 3050 Homework 11 Air Masses and Fronts

Instructions: Make sure that you answer all of the questions completely. Use appropriate units on all numerical answers and answer non-numerical questions with complete sentences. Please write neatly when completing this assignment – if we can’t read your answer you will not get credit for it.

Part 1: Surface Weather Map Analysis - Air Masses

1a. Draw and label contour lines (isobars) every 4 mb on the map of sea level pressure from 12Z 24 Oct 2015 given below.

Name:______

1b. Draw and label contour lines (isotherms) every 10°F on the map of temperature from 12Z 24 Oct 2015 given below.

Name:______

1c. Draw and label contour lines (isodrosotherms) every 10°F on the map of dew point temperature from 12Z 24 Oct 2015 given below.

2a. What type of air mass is present in Louisiana? How did you determine what type of air mass was present at this location?

2b. What is the likely source region for the air mass identified in problem 2a?

Name:______

2c. What type of air mass is present in Nebraska? How did you determine what type of air mass was present at this location?

2d. What is the likely source region for the air mass identified in problem 2c?

2e. What type of air mass is present in western Washington? How did you determine what type of air mass was present at this location?

2f. What is the likely source region for the air mass identified in problem 2e?

Name:______

Part 2: Surface Weather Map Analysis - Fronts

3. Using your contoured weather map data from part 1 and the wind and cloud observations from 12Z 24 Oct 2015 given below mark the position of all fronts over the eastern 2/3 of the country (from Colorado to the east coast).

3a. Mark the position of the fronts on the map below as well as on the maps in problems 1a to 1c.

3b. What data shown on the weather maps did you use when determining the position of the fronts.

3c. What type of air mass is present ahead of the cold front?

3d. What type of air mass is present ahead of the warm front?

Name:______

Part 3: Meteogram Analysis - Fronts

Meteograms show weather observations over some amount of time (usually one day) at a single location. By analyzing the data plotted in a meteogram it is possible to identify the type and timing of frontal passages at a weather station.

4. Use the University of Colorado ATOC weather station meteogram from 18 November 2015 to answer the following questions.

4a. What type of front passed over this weather station?

4b. At what time (to the nearest 30 minutes) did the front pass this weather station?

Name:______

4c. What data in the meteogram did you analyze to determine the timing and type of front that passed over this weather station?

4d. Based on the type of front you identified in your answer to problem 4a what weather features shown on the meteogram did or did not match the typical weather conditions (listed in the tables in the lecture notes) associated with this type of front? What could explain the difference between what was observed and what is typically expected for this type of front?

5. Use the Plainview, NY weather station meteogram from 29 October 2012 to answer the following questions.

Name:______

5a. What type of front passed over this weather station?

5b. At what time (to the nearest 30 minutes) did the front pass this weather station?

5c. What data in the meteogram did you analyze to determine the timing and type of front that passed over this weather station?

5d. Based on the type of front you identified in your answer to problem 5a what weather features shown on the meteogram did or did not match the typical weather conditions (listed in the tables in the lecture notes) associated with this type of front? What could explain the difference between what was observed and what is typically expected for this type of front?