Stability Assessment » SWEAT Index Definition
Definition: SWEAT Index
The Severe Weather Threat (SWEAT) index differs from many of the other severe weather indices in that it takes into account the wind profile in assessing severe weather potential. Inputs include:
- Total Totals index (TT)
- 850 hPa dewpoint
- 850 hPa wind speed and direction
- 500 hPa wind speed and direction
In general, the following conditions lead to a higher SWEAT index and greater probability of severe weather:
- Higher temperature and moisture at low levels
- Cooler temperatures aloft
- Large vertical wind shear
- Wind direction veering with height
SWEAT index values have been empirically linked to convective events as follows:
SWEAT | Severe Weather Potential |
150-300 | Slight severe |
300-400 | Severe possible |
400 or greater | Tornadic possible |