An incredible correlation between vertical geopotential height and the phase of the AAO.
Amazing l have never noted that before. A light bulb moment.
When geopotential height between surface to 100 hPa is positive . The AAO index is negative.
When geopotential height between surface and 100 hPa is negative. The AAO index is positive.
Some convincing proof that the condition of the polar vortex affects our weather.
I will put this geopotential height anomaly in the polar vortex on my weekly observation round.
https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.aao.shtml