Lots of uncertainty Week #2 and beyond on the evolution of the stratospheric PV (according to GEFS). Notice wide range of solutions for the impact of the Week #2 pulse (or lack of it) on the PV (vertical bars in first pic). Reasons? NW Pac pattern + strength of Eurasian ridge. pic.twitter.com/pmsHhvrqPI

— Jason Furtado (@wxjay) January 14, 2018