Temporal and spatial occurrence of strong winds and large snow load amounts in Finland during 1961-2000

• Published in: Silva Fennica
• Main Authors: Hilppa Gregow, Ulla Puranen, Ari Venäläinen, Heli Peltola, Seppo Kellomäki, David Schultz
• Format: Article in Journal/Newspaper
• Language: English
• Published: Finnish Society of Forest Science 2008
• Subjects: coniferous forest; wind climate; precipitation; soil frost; snow; Forestry; SD1-669.5; Northern Finland
• Online Access: https://doi.org/10.14214/sf.231; https://doaj.org/article/4fa13654f1bf4e0591c2d7c78fb33423

Information on the temporal and spatial occurrence of strong winds and snow loads on trees is important for the risk management of wind- and snow-induced damage. Meteorological measurements made at 19 locations across Finland during 1961–2000 are used to understand the temporal and spatial occurrence of strong winds and large snow loads. A Kriging interpolation method was used to produce a spatial analysis of wind-speed events above 11 m s–1, 14 m s–1, and greater or equal to 17 m s–1 and snowfall accumulation above 20 kg m–2 and 30 kg m–2. According to the analysis, wind speeds exceeded 14 m s–1 at least 155 times and reached 17 m s–1 only 5 times at inland locations during the 40 years. Large snowfall accumulations were more frequent in the higher-elevation inland areas than along the coast. The snow load on trees exceeded 20 kg m–2 about 65 times a year when averaged over all 40 years, but was as high as 150 times a year during the mild 1990s. The maximum number of heavy snow-load events occurred in 1994 in northern Finland, consistent with a forest inventory by the Finnish Forest Research Institute in 1992–1994. The findings of this study imply that the risk of wind-induced damage is highest in the late autumn when trees do not have the additional support of frozen soil. In contrast, the risk of snow-induced damage is highest at higher-elevations inland, especially in northern Finland.