As promised yesterday, a robust convection phase of the Madden Julian oscillation (MJO) shifts into the tropical West Pacific just-after mid-month causing a warming influence to develop on the U.S. climate. Snow cover slows the warm-up in the medium range but note the mega-cluster ensemble “most likely” upper air forecast dissipates the polar vortex and creates high pressure across much of the U.S. in 15 days.