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CHAPTER II: ELECTRICITY
continental Europe today, may be expected in Finland as well. Many simulation
models forecast that the number of deep low-pressures with high winds will
increase in the future.
The last strong storms that caused a lot of damage to the forests and serious
electricity blackouts hit Finland in 2001. After these two strong storms, called
Janika (1.11.2001) and Pyry (15.11.2001), the average duration of the electricity
blackout was almost seven hours in rural areas and over four hours in cities.
Storms Pyry and Janika in Finland 2001 42
The first of two storms, named Pyry, hit western Finland on the 1 st of November
2001. Inland ten minute mean wind speeds of 14 – 18 m/s from north-northwest
were measured, with local gusts passing 20 m/s. Although the wind speeds
remained below the official storm limit (21 m/s 10 minute mean wind), the
damages were big in the Ostrobothnia and Keski-Suomi regions.
The second storm, named Janika, of the same magnitude hit two weeks later,
on the 15 th of November 2001. This storm did not reach official storm limits either,
but still caused even more damage than the previous one, mainly due to short gusts
of 30 – 50 m/s. The biggest damages were suffered in the Pirkanmaa, Tavastia and
Uusimaa regions.
During both storms, more than 90 000 trees fell over power distribution lines,
causing several blackouts. About 800 000 customers were affected by the
blackouts, of which 1 600 for more than five days. 30 000 network failures were
repaired and 140 km of power lines were rebuilt. The maintenance costs of the
electricity companies reached 11 million euros.
More than three million cubic metres of trees were damaged, to a value of the
same magnitude as the maintenance costs.
Precautions
A weather forecast was sent out by the Finnish Meteorological Institute in the
morning on the 1st of November. As a consequence, the Department for Rescue
Services of the Ministry of the Interior urged the state provincial offices of
Western Finland and Southern Finland to advise the fire departments to raise their
level of preparedness. In addition, the fire departments were advised to investigate
the availability of backup power sources. Generators were borrowed from
municipalities and other provinces. A significant amount of equipment was also
provided by the Finnish Defence Forces.
In general, the precautions taken before ‘Janika’, on the 15 th of November,
were similar to those taken before ‘Pyry’. The inventory of backup power sources
turned out to have significant value during the second storm as well.
Direct Impacts of Power Blackouts
The role of the emergency response centres was significant in receiving emergency
calls and dispatching rescue units. During the storms, thousands of emergency
calls were received, of which the vast majority concerned requests for clearing
assistance due to fallen trees. In addition, some incidents were reported directly to
42 This section as a whole is based on the information from Viitanen (2002).
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