Summary
The key points to remember are:
- When vertical wind shear is weak, buoyancy processes are the dominant control on convective updrafts and downdrafts
- Positive contributions to buoyant energy come from increases in potential temperature and water vapor
- Updrafts dominate during the early portion of an ordinary cell's life cycle; downdrafts dominate in the later stages
- Thermodynamic diagrams are essential tools for estimating vertical buoyancy distribution, which has important implications for both updraft and downdraft strength
- The Lifted Index (LI) is a simple quantitative estimate of buoyancy in the midlevels of many convective environments
- CAPE provides a quantitative estimate of buoyant energy, especially when calculated using an appropriate low-level average of both moisture and temperature
- CAPE can be used to estimate updraft strength (Wmax)
- A capping inversion or lid, measured by CIN, can either prevent convective storm development entirely or delay initiation until maximum heating is reached
- Downdraft and near-surface outflow strength depend on both precipitation loading and evaporation processes
- In general, drier mid-levels are associated with stronger downdrafts