What does convective available potential energy (CAPE) indicate?

Convective Available Potential Energy (CAPE) is a critical measure used in meteorology to evaluate the potential for convection and severe weather. It represents the amount of energy that is available for rising air parcels to ascend within the atmosphere. When air parcels are heated at the surface, they become less dense and rise. If the conditions are right, particularly if the environmental lapse rate is favorable, this rising air can lead to the development of convective clouds and potential thunderstorms.

Higher values of CAPE indicate a significant potential for strong updrafts, which can be associated with severe weather phenomena such as thunderstorms, hail, and tornadoes. Thus, CAPE serves as a useful indicator for forecasters to assess the intensity and likelihood of convection occurring within a given area.

The other options do not accurately describe CAPE. For instance, it does not relate to high pressure systems or ocean currents, nor does it define a temperature threshold for cloud formation. Instead, it specifically quantifies available energy for vertical motion, making it a key factor in predicting severe weather events.