Lisø PhD Dissertation Manuscript - NTNU

meteorological stations are expected to achieve a value of the exposure coefficient below
0.8. In Canada heavy snowfalls often coincidence with high wind velocities according to
[15]. This is not the pattern in Norway. In Norway heavy snowfalls may occur at low wind
velocities as well as at higher wind velocities.
4.3. The Norwegian climate
Norway is a country with large variations in mean temperatures and wind velocities. In Fig.
6 mean winter temperatures are given (December – February). There is a pattern of low
winter temperatures in the mountainous regions of southern Norway and the inland regions
in the far north. Coastal areas in southwest have temperatures between 0 and – 2.5 °C,
while the inland in the far north has winter temperatures less than –15 °C. In Fig. 7 the
number of days with wind stronger than 5 m/s for months with normal temperature less
than 1 °C is presented. 1 °C was chosen as a limit to consider all months with high
probability of snow and snowdrift. The map also shows number of months with normal
average temperature less than 1 °C. Approximately 90 % of the Norwegian mainland has
six or more months with average temperature less than 1 °C. I.e. six or more months with
possible snow and snowdrift. In Fig. 7 there is a clear pattern of higher probability of high
winds in the costal areas. It should be noted that the costal areas do not always have the
highest number of occurrences, but these regions also have fewer months with
temperatures below 1 °C. In the middle of Norway (approximately 62° – 67° north) this
pattern is most pronounced. In this region the coastal areas have at least one month with
mean temperatures below 1 °C less than the inland, but a higher number of days with wind
above 5 m/s.
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