1. Aspects of climate extremes in Finland Ari Venäläinen, Kirsti Jylhä, Andrea Vajda, Tiina Kilpeläinen, Seppo Saku…

5. CLIMATE RISKS IN FINLAND storms low pressures, tornadoes, down bursts snow slipperiness icing fox turbulence floods an drought hot and cold spells lightning

6. Above 11 ms -1 wind cases on land areas (17 stations)

7. Number of storm days (>21 ms -1 ) at sea areas

8. Number of deep low pressures and rapid change of air pressure in Kajaani

9. Helsinki, Jokioinen, Sodankylä storms 0 50 100 150 200 250 195919631967197119751979198319871991199519992003 Year Deviation from mean (%) 980 hPa casesAbove 20 hPa change Above 9 hP gradient

10. How high wind speed we may experience?

11. TORNADOES Kontiolahti 20.8.2004

12. Tornadoes in Finland

13. Tornadoes in different fujita classes F2+ 1796-1996: 45 % 1997-2003: 8 %

14. 1(2)

15. Climatological characteristics of precipitation in Helsinki

16. 20 50 500 Daily precipitation Helsinki 0 50 100 150 200 101001000 Return period (years) Preciptation (mm/day) 20 50 500

17. Return period of the duration (hour) of a rain event Summer rain events in Helsinki in 1951-2000: duration and precipitation amount Return period of precipitation amount (mm) in a rain event Ref: Tiina Kilpeläinen

18. 1, 2, 3, 6 and 12 month precipitation amounts in Finland Monthly Two months Three months Six months Twelve months

19. 1- month 2- months 3- months 6- months 12- months

20. Snow damages

21. -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 1.10.1.11.1.12. 1.1.1.2.1.3. Date Wind speed (m/s) temeperature (°C) 0 5 10 15 20 25 30 35 40 45 Precipitation (mm) accumulated snow (kg/m2) windtemp accum.prec Kuusamo 1993-1994

22. Above 20 kg snow load on tree branches, days / 10 years

23. ACCLIM part of Finnish adaptation research Climate extremes and estimated climate change based on the latest climate scenarios In the first part of the study return periods of several parameters are calculated

25. DRY SPELL (< 50 mm), summer ret.per.304 Helsinki Kaisaniemi1101 Turku lentoasema 1201 Jokioinen observatorio 1501 Utti lentokenttä 2401 Jyväskylä lentoasema 3201 Kauhava lentokenttä (years)95 %ka95 % ka95 % ka95 % ka95 % ka95 % ka95 % 108290102708292687485657484626775737887 209010012075901097482996982101677486798699 5098110148801001378192120749112374821048793117 100103117164841061488698130779713478881149198129 5001111271839011616696111152841081558710113598107143 Ret.per. 3801 Joensuu lentoasema 5401 Oulu lentoasema 6801 Kuusamo lentoasema 7501 Sodankylä8201 Muonio kk9601 Inari (years)95 %ka95 % ka95 % ka95 % ka95 % ka95 % ka95 % 10626877748194656785737591677588708192 206876918191116707293788010074841117589108 5075861118910313873767783858683961358097131 1008193123951121557578798588 10515283103141 500911081471071351967881828892 9812719290114160

26. And the future? December 2006 mean temperature in Helsinki was +4.0 ºC and March 2007 temperature +3.1ºC. The return periods of this high temperatures is more than 500 years This two months demonstrate the difficulty to estimate the reliably the return periods in rapidly changing climate. How to explain all this to media and general public?