Here's a 5-day average 500mb anomaly from latest GEFS run through end-of-month. This is the retrograding state I'm talking about. This gives each s/w a further west/deeper dive in the succession. By doing this, it can free up room for 1 of the s/w to survive. pic.twitter.com/9NFeFUdy4X

— Anthony Masiello (@antmasiello) January 20, 2021