Surface systems often follow the prevailing airflow at this level. Therefore, the airflow at 700mb, inferred from the geopotential contours and geostrophic balance, can indicate the direction surface systems will take.
Notice that winds over the eastern U.S. are generally out of the south. At the same time, a surface cyclone was centered over the Ohio Valley.
24 hours later, the cyclone propagated northeastward (parallel to the winds at 700mb) and was centered over Eastern Canada.