2. Parameters

Stability Assessment » Showalter Stability Index (SSI) Skew-T Procedure

Skew-T procedure to determine Showalter Stability Index (SSI)
  1. Find the temperature (T) and dewpoint (Td) at 850 hPa
  2. From that T and Td, find the LCL
  3. From the LCL lift the parcel moist-adiabatically to 500 hPa and find the parcel temperature (T′).
  4. Given the 500 hPa sounding temperature (T500), SSI is computed as follows:

SSI = T500 - T′