MAWECLI – MArine and WEather events in the changing CLImate as potential external hazards to nuclear safety

MAWECLI (MArine and WEather events in the changing CLImate as potential external hazards to nuclear safety) aims to increase preparedness towards single and compound marine and atmospheric extreme events that may pose external hazards at nuclear power plant level. The project strives to enhance methods on physical and statistical modelling, extreme value analysis and uncertainty quantification by joining expertise of scientists from various disciplines.

Ukkosmyrsky Suomenlahden yllä
MAWECLI project studies marine and atmospheric extreme events to support nuclear power plant safety in Finland. The photo shows arcus clouds on the leading edge of thunderstorms near the southern coast of Finland on 23 June 2021. Photo: Lassi Karvonen.

The project outcomes include improved estimates on coastal flooding risks, extreme air temperature, and worst-case flooding events caused by cyclones. We also produce estimates of the frequency and magnitude of high wind gusts, impacts of climate change on sea-effect snowfall, and joint effect of intense snowfall and high wind speeds, and make multi-hazard assessment for convective storms, meteotsunamis and lightning.

Project information

Project duration: 1.2.2023–31.1.2026

Funding: The Finnish State Nuclear Waste Management Fund through SAFER2028, National Nuclear Safety and Waste Management Programme 2023–2028 (

Research topics: coastal floods, high wind speeds, sea-effect snowfall scenarios, temperature extremes, cyclones + high sea level + sea surface waves, convective storms + meteotsunamis + lightning, and high winds + intense snowfall.

Project structure and interaction with the stakeholders:

MAWECLI projektin työpakettien rakenne



Rantanen, M., van den Broek, D., Cornér, J., Sinclair, V. A., Johansson, M. M., Särkkä, J., Laurila, T. K., and Jylhä, K., 2024. The Impact of Serial Cyclone Clustering on Extremely High Sea Levels in the Baltic Sea, Geophysical Research Letters, 51, e2023GL107203.

Särkkä, J., Räihä, J., Rantanen, M., and Kämäräinen, M., 2024. Simulating sea level extremes from synthetic low-pressure systems, Nat. Hazards Earth Syst. Sci., 24, 1835–1842.


Pellikka, H., Johansson, M. M., Nordman, M., and Ruosteenoja, K., 2023. Probabilistic projections and past trends of sea level rise in Finland, Nat. Hazards Earth Syst. Sci., 23, 1613–1630.

Ruosteenoja, K., and Jylhä, K. 2023. Heatwave projections for Finland at different levels of global warming derived from CMIP6 simulations. Geophysica, 58, 47–75. Räty, O., Laine, M., Leijala, U., Särkkä, J., and Johansson, M. M., 2023. Bayesian hierarchical modelling of sea-level extremes in the Finnish coastal region, Nat. Hazards Earth Syst. Sci., 23, 2403–2418.

Abstracts, posters and presentations


Rauhala, J.: Derechos in Finland, 11th European Conference on Severe Storms, Bucharest, Romania, 8–12 May 2023, ECSS2023-117,, 2023.

Rauhala, J.: A derecho in northern Europe, 11th European Conference on Severe Storms, Bucharest, Romania, 8–12 May 2023, ECSS2023-149,, 2023.

Rantanen, M., Sinclair, V., Särkkä, J., Johansson, M., Laurila, T., and Jylhä, K.: The impact of serial cyclone clustering on extremely high sea levels in the Baltic Sea, EMS Annual Meeting 2023, Bratislava, Slovakia, 4–8 Sep 2023, EMS2023-195,, 2023.

Preceding projects

MAWECLI is a continuation of previous projects EXWE and PREDICT since 2007 (see details below).

PREDICT: Web page of PREDICT project

EXWE: Presentations and publications (PDF) of EXWE project