I averaged the daily values from Dec-Mar of the AO, NAO, PNA, and EPO teleconnection indices, then took a sum total. I had to reverse the sign of the PNA so that it matched up with the others for the sum total (i.e. standard -PNA and +AO/NAO/EPO are warm east of the Rockies) pic.twitter.com/ZJD7bF4lDS

— griteater (@griteater) April 5, 2020