Shown below are Isobars (light blue color), which represent lines of equal sea level pressure. The closer the lines are to each other represent a larger pressure change over a short distance. This results in stronger winds versus if the isobars were farther apart. Temperature creates pressure differences which then creates wind. As you can see below, the isobars are "tightly packed together" which is a signal that strong winds are possible. Western and Central North Dakota could be in for a prolonged period of strong winds Wednesday through Thursday.