Urban resilience to extreme weather - Sub-seasonal and seasonal forecasts for winter maintenance activities in Helsinki

In Helsinki, there are on average 95 days per year with snow cover (based on the observation period 2000-2019).However, winter conditions vary considerably from year to year.The City of Helsinki is responsible for the maintenance of streets in Helsinki.Winter street maintenance includes snow ploughing, the prevention of slipperiness by sanding, and street cleaning.Street cleaning includes sweeping-up the sand and other grit accumulated over the winter months on the roadways, sidewalks and at public transportation stops, and is especially important in spring, after the snow season.Planning of these maintenance activities are currently done based on the short-term weather forecasts provided by the Finnish Meteorological Institute and from experience gained from the previous years.Within the H2020 E-SHAPE project, under "S7-P2-Urban resilience to extreme weather", a climate service providing sub-seasonal and seasonal climate outlooks tailored for winter street maintenance was developed in cooperation between the Finnish Meteorological Institute (FMI) and the City of Helsinki.Providing useroriented sub-seasonal and seasonal forecast products tailored for winter maintenance activities serves city authorities in planning activities, improving winter safety, and optimizing maintenance costs.