Wind Factors at MSPPosted on June 25, 2014
People often ask how much of a factor wind is when determining which runways will be used for arrivals and departures at Minneapolis-St. Paul International Airport (MSP). The simple answer is that wind direction is a primary consideration during each moment a pilot lands or takes off at any airport, including MSP.
Historical wind data indicate there is a strong and consistent pattern of prevailing winds at MSP. This pattern shows the wind blows most often from the north and northwest of MSP during many months of the year, primarily during winter and spring seasons. The windrose diagram below, provided by Iowa State University of Science and Technology, indicates the wind directions at MSP for January 2014, and the wind speeds that occurred during that month; the average wind speed was 10.8 miles per hour.
Summer and fall wind patterns in the MSP area show the wind direction is most often from the south and southeast. Observations taken from June 1-June 20, 2014 document the average wind speed was 10.2 miles per hour.
It is important to note that these data indicate typical seasonal wind direction patterns, but differences in barometric pressure, uneven heating of the earth's surface, weather fronts, and localized geographic effects can contribute to non-typical wind patterns. Wind direction on the surface of the earth is not necessarily the same direction at altitudes above the surface. Wind speed is another factor that will vary on the surface and at different altitudes, and wind speed will often increase and decrease many times throughout the day.
Pilots and Air Traffic Controllers at MSP use wind speed to gauge how much headwind will exist for aircraft as they arrive and depart. This is because headwind is an important component of lift for an aircraft. Using runways that are most aligned with a headwind will provide the greatest opportunity to generate lift when the air flows over an aircraft's wings.
Wind does not have to blow directly down the runway to generate lift. Crosswinds with some degree of headwind also are helpful for generating lift. The higher the wind speed, the greater the lift.
Sometimes wind direction will be variable. When this happens at MSP, the Air Traffic Controllers will assign runways for aircraft arrivals and departures that are reasonable based on other aircraft operating factors that consider airspace congestion, weather systems outside the Twin Cities metro area, and the MSP Runway Use System. The MSP Runway Use System prioritizes runway assignments in an effort to concentrate aircraft operations over non-residential areas as much as possible when weather and air traffic demand offer flexibility.
For more information about wind factors, please contact the MAC Noise Program Office at 612-726-9411.