The latest available daily NCEP-R1 PNA index (-466.45) value from Dec 20th is already into the 99th %ile (top 20 most -PNA of 2264 days) of all December days since 1948.https://t.co/HWLnROzM3G— Eric Webb (@webberweather) December 22, 2021
The latest available daily NCEP-R1 PNA index (-466.45) value from Dec 20th is already into the 99th %ile (top 20 most -PNA of 2264 days) of all December days since 1948.https://t.co/HWLnROzM3G