This index provides the average wind speed at 10, 50 or 200 hPa between 60°N and 90°N and thus indicates the strength of the stratospheric polar vortex during the polar winter.
The SPV index provides a measure of the circumpolar vortex strength and indirectly relates to a risk of cooling temperatures near the surface in the northern hemisphere, if decreasing below zero.
If the index becomes negative, the vortex disruption is such that a “split" or strong “displacement" is under way, possibly weakening the jet stream in the troposphere.
Example
- Show the historical and forecast SPV strength at 10, 50 and 200 hPa:http://api.meteomatics.com/2018-11-01T00ZP100D:P1D/polar_vortex_10hPa:ms,polar_vortex_50hPa:ms,polar_vortex_200hPa:ms/50,10/html