## 3 Results and Discussion
### High-Wind Events  
The measured wind speed and direction during 2017 are shown in the upper and lower parts of Figure 5a. The average wind speed was \(\bar{w}_{s}=7.7\) m/s, with a seasonal variation given as \(6.9,5.6,8.6\) and \(9.6\) m/s for spring, summer, autumn and winter months, respectively. The 90 th percentile wind speed, \(w_{s}^{\text{O90}}=14.2\) m/s, is shown as a red dashed line in the wind speed plot, and the ten longest events with wind speed above this percentile are the high-wind events that are coloured red in the measurement of both wind speed and direction. These events happened during the autumn and early winter season, and occurred with a wind direction of around 120\({}^{\circ}\).  
The histogram of the measured wind speed during 2017 is shown in Figure 5b, together with Rayleigh and Weibull distributions where the parameters are found using maximum likelihood estimates of the parameters. The histogram shows the highest frequency of wind speeds in the 6-7 m/s bin, where both the Rayleigh and Weibull distributions tend to underestimate the probability of these wind speeds. The histogram also has a slightly higher frequency of wind speeds when \(w_{s}>15\) m/s, compared to the smoother estimated probability density functions.  
Figure 4: Terrain height zoomed in on the D05 location. Contour lines every 100 m, starting at 50 m. Red dot: Location of measurement mast. (**a**) Norwegian Digital Terrain Model, 10 m horizontal resolution. (**b**) WRF D03, 3 km resolution. (**c**) WRF D04, 1 km resolution. (**d**) WRF D05/LES, 90.9 m resolution.  
The wind rose in Figure 5c confirms the tendency of the strongest winds coming from southeast (-east), but also shows that wind from either south or north-northwest was quite frequent this year. With almost no wind from either west or east, the wind blocking from the mountains in those directions is clearly shown in the wind rose. The wind rose also explains the overall location of wind turbines at Fakken, shown in Figure 1c, with two rows of turbines perpendicular to the main wind direction.  
The 10 longest high-wind events are shown in Figure 6 as a function of the length of the event, with the starting time for each event shown in the plot legend. The longest event started on 22 November at 04:00, shown with a thin blue line, and lasted for 72 h. This event occurred during the strongest storm of the year named Ylva according to the Norwegian Meteorological office. During this storm, the measured wind speed, shown in the left plot in Figure 6, also surpassed 25 m/s for about 24 h, which typically is above the cut-off wind speed for wind turbines. The shortest duration of these events is the 9  
Figure 5: Wind measurements from Fakken wind power plant mast. (**a**) Wind speed (**upper**) and direction (**lower**). Red dashed line: 90 th percentile value of the wind speed. Red values: The 10 longest durations above the 90 th percentile. (**b**) Histogram with estimated probability density functions. (**c**) Wind rose showing speed and direction.  
November event that lasts for 12 h, and also note that the 21 November event (16+ h) is just before the Ylva storm event.  
The wind direction in all events is around 120 degrees, as shown in the right plot of Figure 6, which confirms the tendency of southeast (east) wind as discussed for the wind rose for the whole year. Finally, the starting time of these events clearly shows that much of the strong wind occurred during the autumn and early winter season.