How many ensemble members are indicating the potential for a weaker polar vortex?

Answer: a majority.

The UKMET, for example, targets mid-November through mid-December for a slowing of the typical westerly winds at 10 hPa.

Impacts on our weather, if any, may lag somewhat. pic.twitter.com/1GyhzN62Iz

— Ben Noll (@BenNollWeather) August 15, 2021