Andrea Vajda

Finnish Meteorological Institute · Weather and Climate Change Impact Research

Between October 2023 and January 2024, a remarkably persistent cold air anomaly prevailed over Fennoscandia on an otherwise record‐warm planet. This article describes the temperature anomalies, atmospheric circulation and seasonal predictions associated with the cold blob. The 4‐month period from October to January was the third coldest in Fennosca...

Background Ticks are responsible for transmitting several notable pathogens worldwide. Finland lies in a zone where two human-biting tick species co-occur: Ixodesricinus and Ixodespersulcatus. Tick densities have increased in boreal regions worldwide during past decades, and tick-borne pathogens have been identified as one of the major threats to p...

The subseasonal forecasts from the ECMWF (European Centre for Medium-Range Weather Forecasts) were used to construct weekly mean wind speed forecasts for the spatially aggregated area in Finland. Reforecasts for the winters (November, December and January) of 2016–2017 and 2017–2018 were analysed. The ERA-Interim reanalysis was used as observations...

Pogosta disease is a mosquito-borne infection, caused by Sindbis virus (SINV), which causes epidemics of febrile rash and arthritis in Northern Europe and South Africa. Resident grouse and migratory birds play a significant role as amplifying hosts and various mosquito species, including Aedes cinereus, Culex pipiens, Cx. torrentium and Culiseta mo...

Seasonal climate forecast products offer useful information for farmers supporting them in planning and making decisions in their management practices, such as crop choice, planting and harvesting time, and water management. Driven by the need of stakeholders for tailored seasonal forecast products, our goal was to assess the applicability of seaso...

Climate services are defined as the provision of climate information in a way that assists decision making by individuals and organizations. Climate indices are useful synthetic measures, easily comprehensible for the stakeholders, managers, end-users and the public in general. Link to the article: http://www.ilmastokatsaus.fi/2020/05/15/sectoral-b...

Wildfires are critical natural hazards, both in the Mediterranean and boreal regions of Europe, causing significant environmental and economic damages and losses. Operational drought and fire risk forecast services on sub-seasonal, seasonal and climatic scale allow fire protection authorities to increase preparedness and response in drought and fir...

Seasonal forecasts for forestry have been developed in the Finnish Meteorological Institute in cooperation with Finnish end-users. Such forecasts could help forest companies in preparing for adverse conditions of timber harvesting operations. Bearing capacity for harvesting operations is dependent on soil moisture, and skillful forecasts have poten...

The general objective of EXWE was to give better estimates of probabilities of extreme geophysical events that affect the design principles of nuclear power plants (NPPs) and may pose external threats to the plants. Extreme incidents in weather, sea level events and space weather, as well as atmospheric dispersion were considered. Various observati...

In Finland peat has been used for energy production, for agricultural and horticultural and environmental purposes. Success of peat production depends on weather. Dry and sunny conditions are needed, and weather forecasts give the basis for the planning the activities of relatively short production season. In 2017, by request of the leading Finnish...

The effects of climate change on freezing rain in Europe under medium (RCP4.5) and strong (RCP8.5) future emission scenarios were assessed using seven regional climate model simulations conducted within the World Climate Research Project's COordinated Regional climate Downscaling Experiment over the European Domain (EURO-CORDEX). A precipitation-ty...

Major nuclear accidents are typically low-probability–high-consequence events. This paper focuses on weather and sea-level events that might affect the safety of nuclear power plants (NPPs). Flooding risks at Finnish NPP sites have been re-evaluated based on investigations of long-term changes and short-term variations in sea level, which has led t...

An online survey was used to map the needs and preferences of the Finnish general public concerning extended-range forecasts and their presentation. First analyses of the survey were used to guide the co-design process of novel extended-range forecasts to be developed and tested during the project. In addition, the survey was used to engage the res...

Background and Objectives: Freezing rain is one of the most dangerous and costliest winter hazards causing significant damage and failure of critical infrastructure due to ice accumulation. Ice accumulation on power lines have damaging effect on power distribution and transmission resulting in power outages and significant economic losses. There is...

A method for estimating the occurrence of freezing rain (FZRA) in gridded atmospheric data sets was evaluated, calibrated against SYNOP weather station observations, and applied to the ERA-Interim reanalysis for climatological studies of the phenomenon. The algorithm, originally developed at the Finnish Meteorological Institute for detecting the pr...

A method for estimating the occurrence of freezing rain (FZRA) in gridded atmospheric datasets was evaluated, calibrated against SYNOP weather station observations, and applied to the ERA-Interim reanalysis for climatological studies of the phenomenon. The algorithm, originally developed for detecting the precipitation type in numerical weather pre...

This report presents analyses of the probability of hydro-meteorological hazard occurrence, which were carried out within the RAIN project. Those probabilities and their projected changes1 during the 21st century are an input to subsequent risk analyses which assist the identification of optimal adaptation measures. These data are available at the...

Studying changes in storm-induced forest damage in Finland has not been possible previously due to the lack of continuous, long series of impact data. We overcome this by combining emergency rescue data from the Finnish rescue services "PRONTO" (2011-) with ERA-Interim reanalysis data of wind gusts and soil temperatures to define exceedance thresho...

Forest fires constitute the second largest form of disturbance to the Finnish boreal forest environment, playing a significant role in vegetation succession and landscape transformation. Warning systems aiming to minimize the risk of fires are based on fire danger estimation methods using weather information. In this study, the operational fire dan...

This report summarises the work done in 7 FP project EWENT, its first work package. D1 deliverable introduces a review of extreme weather phenomena and identifies their impacts and consequences on European transport system. All modes of transport are covered. Two main methods are used. First, there is an extensive literature review on extreme weath...

Severe weather can have serious repercussions in the transport sector as a whole by increasing the number of accidents, injuries and other damage, as well as leading to highly increased travel times. This study, a component of the EU FP7 Project EWENT, delineates a Europe-wide climatology of adverse and extreme weather events that can be expected t...

The aim of this study was to find links between extreme weather events and the regional vulnerability of transportation in Europe. The same meteorological phenomenon has different impacts on societies due to their geographic or climatic locations, topography, geological environment as well as social and technological vulnerability. This fact direct...

This paper is a summary from the EWENT-project Deliverable D5.1 Weather hazards and vulnerabilities for the European transport system – a risk panorama. The original deliverable can be found in http://ewent.vtt.fi/ EWENT- project (Extreme weather impacts on European networks of transport, Grant Nr 233919) was co-funded by the European Commission un...

This report is the output of the first step of the review of models for multi-sectorial consequences dealed with CRISMA Project. It aims at defining and then providing the necessary models for the assessment and management of hazard, vulnerability and losses, and capacities. The framework for multi-risk assessment and management is one objective de...

The purpose of work package 4 of the EWENT project, findings of which are summarized in this deliverable, is to provide concrete monetary valuations of the impact of extreme weather phenomena on the transport system. This target is operationalized through several steps of research activities: - Review of methodologies used to value accidents and tr...

This deliverable of EWENT project estimates the risks of extreme weather on European transport system. The main object of work package 5 in EWENT project was to perform a risk analysis based on impact and probability assessments carried out in earlier work packages (WP2-WP3). The results of WP 5 can be used as a starting point when deciding on the...

Adverse and extreme weather events, such as heavy rain, heavy snowfall, strong winds, extreme heat and cold, drought and reduced visibility, can have a negative impact on the transport sector, causing injuries and damages as well as other economic losses. Fre-quency and intensity of weather and climate extremes are likely to continue to change in t...

Adverse and extreme weather events, such as heavy rain, heavy snowfall, strong winds, extreme heat and cold, drought and reduced visibility, can have a negative impact on the transport sector, causing injuries and damages as well as other economic losses. Frequency and intensity of weather and climate extremes are likely to continue to change in th...

Extreme weather events, such as heavy rain and snow events, storms, strong winds, low visibility, hail and extreme temperatures can have negative impact on transport sector, causing severe damages and large economic losses. Weather and climate extremes have been changed over the last few decades and are likely to continue to change in the future du...

Wintry weather conditions have high impact on transportation. Sub-zero temperatures combined to snowfall result in traffic jams and increased accident rate. Dense snowfall causes poor grip between the road surface and tires and reduces the visibility, thus increasing the risk for severe pile-ups on highways. Low temperature and snowfall have a stro...

Snowmelt timing is a critical factor for tree growth ill high latitudes, but threshold conditions with respect to Soil Moisture availability and soil temperature for the root-zone processes are not well known. We monitored snowpack thickness, air and soil temperature, and water content in the soil. sapwood, and roots of downy birch (Betula pubescen...

The recurrence of heavy precipitation, dry spells and deep snow cover were estimated based on observations at about ten stations in Finland during about five decades. The 10-year return levels were assessed by means of the so-called "peak over threshold" (POT) method. The return levels of the annual maximum snow depth ranged from about 65 cm in sou...

The structure and function of northern ecosystems are strongly influenced by climate change and variability and by human-induced disturbances. The projected global change is likely to have a pronounced effect on the distribution and productivity of different species, generating large changes in the equilibrium at the tree-line. In turn, movement of...

The presence of permanent snow cover for 200-220 days of the year has a determining role in the energy, hydrological and ecological processes at the climate-driven spruce (Picea abies) timberline in Lapland. Disturbances, such as forest fires or forest harvesting change the vegetation pattern and influence the spatial variation of snow cover. This...

In northern ecosystems near the climatological timberline, the interactions between vegetation and disturbances, such as forest fire, are particularly important, as the changes in vegetation may produce large feedbacks into the climate. The changed climate and the altered surface conditions may in turn prevent the vegetation from returning to its o...

At high latitudes in Lapland, near the climatological timberline, forestry and other environmental research require detailed information about the spatial variation of climate. In this study, the influence of local geographical factors on the climate in northern Finland (Lapland), as well as the applicability of the kriging interpolation method in...