This is a classic East Asia positive Mountain Torque (+MT) event w/ -MSLPa in the lee of the Himalayas. This creates a cross-barrier PGF that opposes earth's rotation, slowing it a tad. The atmosphere speeds up to conserve angular momentum thus, we get a day 6-10 NP jet extension pic.twitter.com/ZLVqrs55eE

— Eric Webb (@webberweather) October 17, 2018