The #BananaHigh -- one of 1st things I learned in synoptic forecasting classes @psumeteo 40 years ago! If arctic high pressure extends to east as well as south, curving around a low pressure system, that can produce a long swath of snow, which this storm will have.❄️ #Harper pic.twitter.com/40siMye6Zp

— Stu Ostro (@StuOstro) January 18, 2019