Extratropical Cyclones Forming East of the Rocky Mountains

Edition 1 - Example of Rocky Mountain Cyclone: Sea Level Pressure and Wind Vectors of the April 2001 Cyclone: A strong surface low associated with a Rocky Mountain cyclone develops on 10 April 2000. The low intensifies to a central pressure of less than 988mb as it travels northeastward across the western Great Lakes. Strong winds associated with the strong pressure gradient in the vicinity of the low are indicated by the green arrows. Longer arrows indicate faster winds; arrows point to the direction the air is flowing toward.