Upper-level 30,000-ft jet stream flow aloft and low-level/surface temp distribution
Polar Jet holds Arctic-cold air far north across northern Canada

  • Subtropical Jet flows W-E over the Chicago area – Chicago positioned in the southern edge of “Cool” Transitional air
  • Short Wave #1 gave cloudiness/drizzle to the Chicago area Saturday – it will continue to move off to the east, merging with the nearly stationary Short Wave # 2 and intensifying off the NE U.S. coast mid-week.
  •  Short wave #3 will move east into the Rockies, where it will intensify – developing into a major Plains winter storm system midweek.