Big change in the SH #polarvortex has begun as a minor #SSW occurs. The substantial build up of heat fluxes suggests that more weakening is possible, however. This could potentially be the largest event since 2002, when the only major #SSW occurred in the SH that we know of. pic.twitter.com/eoxYZJawbY

— Dr. Amy H Butler (@DrAHButler) August 27, 2019