Airport noise? Blame it on el Nino

The prevailing jet stream over the Midwest from the south and west has brought the unusual warmth in the last few weeks. Despite today’s return to cooler weather, that trend is likely to continue for awhile.

And that might be part of the reason for an increase in jet noise complaints recently — the wind.

In its latest noise update, the Metropolitan Airports Commission says an unusual wind pattern for this time of the year is forcing jets to take off to the southeast, and land from the direction of Minneapolis’ neighborhoods.

As a direct result of the prevailing wind patterns, the airport was in a south flow configuration for 35 out of 61 days in September and October 2015. At times, this configuration was used for many consecutive days as winds continued to blow from the south and east. When MSP operates in a south flow, aircraft depart from Runways 12L, 12R, and 17 (over Eagan, Mendota Heights and Bloomington); arrivals land on Runways 12L and 12R (over Minneapolis). Persistent use of the south flow is rare, particularly during late fall, when north winds typically become more common.

There are several factors in selecting which runway to use but wind direction is the most important. Aircraft take off into the wind to take advantage of the airspeed advantage to speed takeoff.

This graphic shows the effect of the wind on where the takeoff noise was directed compared to the same period a year ago.

There may be some temporary relief for some neighborhoods. with the the cooler temps, winds have shifted more to the west and northwest.