The foehn over Sofia Airport increased the work of air traffic controllers

The strong winds led to problems for aviation on 17 and 18 March, because of the high speed, gusts and lateral direction to the runway of Sofia Airport. The maximum wind speed reached 22 m/s or 80 km/h. The crews reported wind shear throughout the night while BULATSA’s air traffic controllers proved exceptional professionalism in servicing the airspace.
The phenomenon is called foehn and occurs in the cold half of the year. A cyclone influenced the weather as warm air from the Mediterranean flew at high velocity over the ground, streaming above the Mountain of Vitosha and accelerated during its descend over the valley of Sofia. This raised the temperatures above the normal for the season.
The turbulence and wind shear (change of wind speed and/or direction from one point in space to another) caused discomfort for passengers and increased the workload of air crews and air traffic controllers.
The workload of BULATSA’s meteorologists was also increased as they were required to provide the most accurate forecast for the wind speed, direction and the duration of the phenomenon. These issues reflect on both the professionals and the flying public, so the information needs to be provided in a timely manner. A good coordination was in place and no incidents occurred in these critical periods.
A standard procedure for the aircraft to ‘Go Around’ is in place for such situations where the safe landing is a paramount.
The chart below shows the average speed (blue) and the wind gusts (red). Data source: Aerodrome Weather Observation System.