Polar Vortex February 2024. The stronger it is, the faster it spins, and the more bottled up its frigid air remains. Early data shows that the polar vortex is likely to be weaker than normal in the winter of 2024/2025.
When the ao turns negative, it tends to mean that something has happened in the arctic that leads to milder conditions and a weaker polar vortex, allowing cold to meander. A strong/stable polar vortex usually means strong polar.