American Meteorological Society Certification Thermodynamics and Atmospheric Stability 3

Question 1

What is a capping inversion (or 'cap') in severe weather forecasting?

Accepted Answer

A warm layer aloft that prevents premature convection while allowing CAPE to build

Answer

A capping inversion is a warm layer in the lower troposphere that suppresses convection until sufficient forcing breaks the cap, often leading to explosive thunderstorm development.

Question 2

What does the K-Index measure in severe weather forecasting?

Accepted Answer

Thunderstorm potential based on temperature, dew point, and lapse rate

Answer

The K-Index combines low-level moisture, temperature lapse rate, and mid-level moisture saturation to estimate thunderstorm potential.

Question 3

Virtual temperature is used in atmospheric thermodynamics to account for what effect?

Accepted Answer

The effect of water vapor on air buoyancy and density

Answer

Virtual temperature treats moist air as equivalent dry air, accounting for the lower density of water vapor relative to dry air.

Question 4

The Brunt-Väisälä frequency measures what atmospheric property?

Accepted Answer

Buoyancy oscillation frequency of a displaced air parcel in a stable layer

Answer

The Brunt-Väisälä (or buoyancy) frequency describes how fast a displaced parcel oscillates vertically in a stably stratified atmosphere.

Question 5

Convective instability (potential instability) is assessed by examining changes in what variable with height?

Accepted Answer

Equivalent potential temperature (theta-e)

Answer

Convective (potential) instability exists when theta-e decreases with height, meaning the layer becomes unstable if lifted as a whole.

American Meteorological Society Certification Practice Test

American Meteorological Society Certification Practice Test

American Meteorological Society Certification Thermodynamics and Atmospheric Stability 3