Handout (1.5 MB)

To test the effect of deviations from PI Theory's idealized boundary layer profiles, observationally-based near-surface temperature and moisture profiles are used to calculate PI. These values are compared to PI values calculated using PI Theory's idealized boundary layer. Temperature and moisture variations are each found to affect PI by an average of 3-4 m s-1, showing that conditions inside a TC play a non-negligible role in determining that storm's PI.

Finally, for four TCs in which a distinct specific entropy minimum is observed far from the TC center, PI is calculated using this minimum as the environment and compared to PI calculated using the standard observed environment. It is found that setting the environment to the radius of minimum entropy increases PI by 2 to 20 m s-1. This demonstrates that the location of the environment chosen for real-time PI calculation can greatly affect the value calculated.