Severe Weather in Norway

Tornadoes forms during severe thunderstorms. For thunderstorms to form cold and warm air masses have to meet, and the warmer and moister the warm air mass is, the more severe thunderstorms is created. A tornado is defined as a violent rotating column of air. The rotation is due to winds at different altitudes, blowing in different speeds which creates a wind share. The rotating air is rotating horizontally first but is lifted from the ground by the updraft of the thunderstorm. Once it is lifted nearly vertically it is considered a mesocyclone.

In the United States the tornadoes usually travels from southwest to northeast. This is because the tornadoes moves in the same direction as the thunderstorms that are producing them. The average number of tornadoes in the US each year is estimated to be over 1000 according to this webpage:
http://scienceline.ucsb.edu/getkey.php?key=1073

Tornadoes do also occur in Norway, but the tornadoes in Norway happen in a lot smaller scale of those in the US though. Because the tornadoes in Norway are at a F0 or F1 on the Fujita-scale the extent of damage is also very small compared to those than can develop in the US. In Norway the surface temperature is not high enough and also the temperature differences in the air masses is not big enough to create great tornadoes. Norway have experienced tornadoes at a F2 on the Fujita-Scale, but these tornadoes has been very short-term tornadoes.There is no recorded number on how often Norway experiences tornadoes each year. One reason is that a lot of the tornadoes in Norway are so small and often unnoticed. Each summer Norway experiences events of eddies, that can be somewhat similar to those like an tornadoes but of course not to compared to tornadoes. They are just both rotating winds.
Norway does experience on a average 100.000 thunderstorms each year though. Beneath are some web-pages where I found some information on Tornadoes in Norway. The last web-page said that Norway experiences "baby-tornadoes" every ten years.
http://no.wikipedia.org/wiki/Tornado#Tornadoer_i_Norge
http://forskning.no/klima-meteorologi-vaer-og-vind/2014/11/tornadoene-kommer-tettere
http://www.vg.no/nyheter/innenriks/vaer-og-uvaer/baby-tornado-herjet-soer-norge/a/125133/

This figure shows the distribution of tornadoes in the world. United States, Australia and Europe seems to experience the most tornadoes. Even though the US experience a lot more tornadoes and more extreme events of tornadoes, Europe is also considered as a tornado active continent. Norway is located in Europe and I have attached an arrow so it will be easier for you to locate Norway. As you can see the southern part in Norway experiences tornadoes, while the northern parts does not. 

The figure is downloaded from: http://www.ustornadoes.com/2013/07/25/from-domestic-to-international-tornadoes-around-the-world/

By looking at the graph there seem to have been an increase in tornado activity over time. People speculate if the increase in tornadoes is caused by the increase in temperatures due to global warming.

The graph shows an increase in tornadoes the last 30 years. It is hard to believe that we already have noticed such effect from the global warming. This does not necessarily mean that there are more tornadoes today than for 30 years ago. The reporting systems has changed over time, and I believe that more tornadoes is reported now, than from 30 years ago. Also, people most certainly know more now than for 30 years ago about weather and which weather events can be defined as tornadoes. 

For hurricanes to develop there need to be consistent heating of the surface, high humidity and cumulus or cumulonimbus clouds present. High surface temperatures and high humidity is mostly seen in the tropics, hence there is where the hurricanes is mostly seen. Norway is not located in the tropics but in the subarctics and do not have high enough surface temperature nor high enough air humidity to develop severe hurricanes. 

Hurricanes are not called hurricanes everywhere, but have other names depending on where they occur. In the Atlantic and the East Pacific the hurricanes are called hurricanes. In the Indian Ocean and near Australia the term "tropical cyclones" are used when taking about a hurricane. Off the coast of China and in Indonesia they use the name "Typhoons"when they are talking about events that we know as hurricanes. 

Figure downloaded from: http://www.learnnc.org/lp/editions/nchist-recent/6248

The general path of hurricanes in US is from southeast to northwest. The hurricanes often follow this path because the trade winds are taking the hurricanes with them when blowing from the east to west in the tropics. 

About five hurricanes strikes the coastline of US every 3 years according to this website:

http://www.ussartf.org/hurricanes.htm

Norway do experience hurricanes. The last big hurricane that reached Norway was in 1992, the year I was born, in New Years Eve. The hurricane was located in my home town and we still see evidences from the storm around my house, 22 years later..Scientists claims that such huge hurricanes will statically only occur every 200 years in Norway. 

Each year Norway experience only a couple events of winds that reach the strength to be called an hurricane. But normally these hurricanes only lasts for about ten minutes. 

http://www.kriseinfo.no/Vaer-og-natur/Ekstremvar/Hva-er-en-storm/

http://met.no/Nyttårsorkanen+1.+januar+1992.pBl77BFEFTN99TVQ721-U9or6XyogdVPL28nMhPLZB9MtlY05hRDI2p.ips