Extratropical Cyclones Forming East of the Rocky Mountains

Online 10.3: An Upper-Level Cyclone Crosses the Rockies 850 mb: Animation of 850mb heights and temperatures show the development of a strong low east of the Rocky Mountains late in the animation. The cyclone tracks northeastward. Cold air (blue and purple) is transported southward on the west side of the cyclone and warm air (yellow) is advected northward, east of the cyclone.