• Jet streams
    1. Which of the four different jet streams that occur in the Northern Hemisphere influence the weather here in Tucson?
    2. Which of the four different jet streams that occur in the Northern Hemisphere has winds that blow from the east toward the west?
  • Fronts
    1. Know the 4 different types of fronts mentioned in class and the meteorological symbols for them.
    2. Why is the cold air below the warm air in each type?
    3. What can you say about the temperature of the air that is rising in each type?
    4. Look at the description of the weather conditions associated with the different fronts given via the figures on pages 52-55.  Note how the weather conditions change from before to after the front passes a location.
    5. Temperature change is not the only way to determine when a front has passed. This list is what a meteorologist would look for find a front on a weather map.
    6. Based upon the following weather forecasts, what type of front will most likely pass the area?
      1. Light rain and cold today, with temperatures just above freezing.  Southeasterly winds shifting to westerly tonight.  Turning colder with rain becoming heavy and possibly changing to snow.
      2. Cool today with rain becoming heavy at times by this afternoon.  Warmer tomorrow.  Winds southeasterly becoming westerly by tomorrow morning.
      3. Increasing cloudiness and warm today, with the possibility of showers by evening.  Turning much colder tonight.  Winds southwesterly, becoming gusty and shifting to northwesterly by tonight.
      4. Increasing high cloudiness and cold this morning.  Clouds increasing and lowering this afternoon, with a chance of snow or rain tonight.  Precipitation ending tomorrow morning.  Turning much warmer.  Winds light easterly today, becoming southeasterly tonight and southwesterly tomorrow.
  • Troughs & ridges
    1. In words, troughs are the axis of low pressure regions and ridges are the axis of high pressure regions.  You should be able to recognize these on both a sea level pressure map or a upper air map.
    2. Cold fronts are usually found in troughs, but not all troughs contain cold fronts.
    3. The spacing between troughs and ridges can very considerable, but what meteorologist call "long waves" are typically spaced such that a trough will be in the east portion of the U.S. while a ridge will be in the western portion (See lower right figure on page 57).  Given that information and what has been said about highs and lows and general weather conditions, how would the weather compare between the eastern and western portions of the country in this case?
    4. The "long wave" pattern usually guides extra tropical cyclones, while the "short waves" can help to start extra tropical cyclones.
    5. The on the east side of an upper level ridge (which is the west side of a trough) the air is converging, while the air on the east side of an upper level trough is diverging.  Remembering the simple side view of a low pressure with converging air at the surface and diverging air above, where would you find a surface low pressure relative to the upper level trough?
    6. When upper level divergence is greater than lower level convergence (more air is taken out at the top than put in the bottom), surface pressure will decrease an a low will "intensify."  This is why lows tend to move toward a region with upper level divergence.
  • Station model & weather maps
    1. Know how to read a sample station model representation of meteorological data.
    2. You'll only be expected to know the following weather symbols:
  • Extra tropical cyclones or storms
    1. This is the low pressure that usually ties a cold front to a warm front.  The life cycle is shown on page 50.
    2. Using what you know about how winds circulate around a low pressure in the Northern Hemisphere, and the general temperature distribution (cold air toward the poles and warmer air toward the equator), you should understand the stereotypical top view of an extra tropical cyclone in the Northern Hemisphere.  This is much like the picture on the upper right of page 53, with the storming moving from the west toward the east and the warm front moving northward with the cold front moving eastward.
    3. Using the same logic as above, you should be able to draw what a extra tropical cyclone would look like in the Southern Hemisphere.
    4. Would a extra tropical cyclone intensify or dissipate if the upper level trough were located to the east of the surface low pressure?
    5. List three regions in North America where extra tropical cyclones tend to develop or form.  Hint: See the lower figure on page 56.