# Key for Lab Exercise 4 and Homework 3: Weather Pattern and Thunderstorm Potential Diagnosis, May 10, 2011

1. Surface Chart
• Place values on the isobars, as explained in class
• Label Highs and Lows.
• Draw Streamlines for the midsection of the country (color coded; blue=cold; red=warm moist; brown=warm dry)
• Analyze the boundaries (use proper symbols and colors.
2. 500 mb and 300 mb Charts
• Analyze troughs and ridges, highs and lows.
3. Surface-based CAPE and CIN Analysis. Notice the locations A, B and C. (100 points)
1. If thunderstorms develop, at which of the three locations would thunderstorm updrafts at the Equilibrium Level be the strongest and why?

Thunderstorms, if they developed, would be characterized by the strongest updrafts at Location C. This is because the CAPE values there are the greatest of any of the locations shown. Since the vertical velocity at the EL is directly proportional to CAPE, the potential vertical velocities would be greatest for the location with the greatest CAPE, regardless of the CIN.

2. At which of the three locations is there no chance of thunderstorms and why?

No thunderstorms would develop at Location A because there is no CAPE there. This means that in no circumstance would buoyant updrafts develop.

3. At which of the three locations is thunderstorm development most likely at the time of the chart and why?

Thunderstorms are most likely to develop at Location C at the time of the chart. At that, there is CAPE and a negligible amount of CIN. This suggests that the LFC is nearly at the ground or at the ground there.

4. Del Rio Texas Sounding
• Anlayze for afternoon heating...determine CT, CCL, show CAPE and CIN areas.
• Examine the forecast maximum temperature for the area and comment on whether the potential of the "loaded gun" will be "realized

The convective temperature is approximately 42C (107F). The forecast maximum temperature is around 100F. It appears that the potential of the loaded gun will NOT be realized.