1. Upper Air Diagrams
Dewpoint will be replaced with the dewpoint depression, which is the difference between the temperature and dewpoint.
You will not see a negative dew point depression.
Pressure changes to a height in meters. This can be seen as the thickness between the surface and the corresponding level.
Warmer temps = higher thickness
Lower temps = lower thickness

2. Stacked or Tilted Trough?
In areas of deep low pressure or heights, the trough axis can be analyzed at each level of the atmosphere.
If axis at each level is in the same general
location, then it can be thought of as vertically stacked.
If the axis is in a different location, it can be classified as tilted with height.
Why is this important?

3. Stacked or Tilted Trough? (cont.)
Strong developing low pressure systems tend to tilted with height. Why?
500 mb heights are influenced by the temperature of the layer from the surface to 500 mb.
Behind a cold front, cooler air will aide in decreasing the vertical depth of the atmosphere just behind the front.
Colder air = Lower heights
In developing low pressure, the axis at each level with height will tilt toward cooler air.

4. Strengthening - mT air rises, with cP air sinking - Helps to move system along

5. Stacked or Tilted Trough? (cont.)
Once an occlusion occurs in an area of low pressure, cooler air is wrapped around the low.
Temperatures are about the same around the system.
Occlusion = weakening of system, cold front catches the warm front.
Example: Slow moving system or cutoff low. More convergence at surface compared to divergence aloft.

6. Weakening - In occlusion, warm air is located over the cooler air
Weakening - In occlusion, warm air is located over the cooler air. - Low begins to fill