Pertti Nurmi

Verification of Nowcasts from the WWRP Sydney 2000 Forecast Demonstration Project

Abstract The verification phase of the World Weather Research Programme (WWRP) Sydney 2000 Forecast Demonstration Project (FDP) was intended to measure the skill of the participating nowcast algorithms in predicting the location of convection, rainfall rate and occurrence, wind speed and direction, severe thunderstorm wind gusts, and hail location and size. An additional question of interest was whether forecasters could improve the quality of the nowcasts compared to the FDP products alone. The nowcasts were verified using a variety of statistical techniques. Observational data came from radar reflectivity and rainfall analyses, a network of rain gauges, and human (spotter) observations. The verification results showed that the cell tracking algorithms predicted the location of the strongest cells with a mean error of about 15–30 km for a 1-h forecast, and were usually more accurate than an extrapolation (Lagrangian persistence) forecast. Mean location errors for the area tracking schemes were on the ord...

Wireless traffic service platform for combined vehicle-to-vehicle and vehicle-to-infrastructure communications

Vehicular wireless communications and vehicular ad hoc networks are nowadays widely identified enablers for improving traffic safety and efficiency, and a large number of suggestions for vehicle-to-vehicle and vehicle-to-infrastructure communication have been presented. The focus is typically on bilateral communication between two vehicles or on broadcasting information from one vehicle or infrastructure to vehicles in the surrounding area. In the Carlink project [1, 2] of the European Celtic program call 3 we have developed an intelligent hybrid wireless traffic service platform between cars supported by roadside wireless base stations. Communication between cars will be arranged in an ad hoc manner, supported by wireless base station connection to the backbone network whenever possible. The platform consists of a specific set of services (e.g., local road weather service and incident warning service), but a variety of services can be integrated to this kind of a system. The ultimate goal was to enhance traffic safety and smoothness, but also to generate a completely new communication entity, allowing new types of applications, services, and business opportunities. In this article we present the concept and example services of the Carlink platform. The platform simulations, field tests, and analysis show that the platform operability and efficiency are suitable for a large-scale traffic system, to be verified in the pilot system deployment.

Severe weather affecting European transport systems: the identification, classification and frequencies of events

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 to affect the transport network. We first define and classify the relevant severe weather events by investigating the effects of hazardous conditions on different transportation modes and the infrastructure. Consideration is given to individual phenomena such as snowfall, heavy precipitation, heat waves, cold spells, wind gusts; a combined phenomenon, the blizzard, is also considered. The frequency of severe weather events, together with the changes in their spatial extension and intensity, is analyzed based on the E-OBS dataset (1971–2000) and the ERA-Interim reanalysis dataset (1989–2010). Northern Europe and the Alpine region are the areas most impacted by winter extremes, such as snowfall, cold spells and winter storms, the frequency of heavy snowfall. The frequency of hot days is highest in Southern Europe. Severe winds and blizzards are the most common over the Atlantic and along its shores. Although heavy rainfall may affect the whole continent on an annual basis, extreme precipitation events are relative sparse, affecting particularly the Alps and the Atlantic coastline. A European regionalization covering similar impacts on the transport network is performed.

Road weather station acting as a wireless service hotspot for vehicles

The European Eureka/Celtic Plus project CoMoSeF (Co-operative Mobility Services of the Future) aims to create co-operative mobility solutions (including devices and applications), feasible for large scale deployment. In practice this means combined vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I), communication system employing interactive example services related to safety and weather information exchange. In this paper we present FMI (Finnish Meteorological Institute) approach to employ CoMoSef vehicular networking entity by creating a specific service hotspot for vehicles bypassing the combined Road Weather Station (RWS)/Road Side Unit (RSU). Local road weather and route weather (a special type of weather service tailored for dedicated road stretches, constructed both from FMI meteorological systems data and the data collected from local RWSs) are the obvious services offered, but in addition to them there is a variety of services available, from specialized weather data into more general traffic information and local accident warnings. The ultimate aim is to provide data to vehicles regardless of their communication devices available. The supported media at the moment consists of IEEE 802.11p and traditional Wi-Fi communication operated through special vehicle computer, Android-based tablet PC or standard laptop computer, but it is expected to be supplemented at least with iPad- and Jolla-devices, respectively.

Wireless traffic safety network for incident and weather information

Vehicular wireless communications with Vehicular Ad Hoc Networks (VANET) utilizing Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communication tools are key technological approaches in efforts to improve traffic safety and efficiency. The European project WiSafeCar (under the Celtic cluster of the EUREKA network) has as one of its key targets to develop an intelligent hybrid wireless traffic safety network between vehicles and infrastructure. Vehicle based sensors and observations are exploited to generate intelligent real-time services on a service platform for vehicles. WiSafeCar considers not only urban areas, but also the special case of operating in rural areas where no high-density base station (road side unit) network for V2I communication is available. Hybrid communication of cellular and IEEE 802.11p based wireless vehicular networking has been employed, with the primary objective of the cellular communication to provide an alternative solution in areas outside of the range of the wireless vehicular network.

Comparing the Performance of Two Road Weather Models in the Netherlands

AbstractHigh-quality road condition forecasts are a prerequisite for road authorities to ensure wintertime road safety. Harsh winter conditions can cause problems for traffic not only in countries where snowy winters are common but also in regions where the temperature drops below the freezing point occasionally. This study reports on the evaluation of the Royal Netherlands Meteorological Institute’s (KNMI) new road weather forecasting model by comparing it with the Finnish Meteorological Institute’s (FMI) road weather model, both run for 321 Dutch road weather stations, four times daily (0300, 0900, 1500, and 2100 UTC) during the test period, 15 January–28 February 2015. Road surface temperature forecasts by both models were evaluated against observations. The KNMI model produced slightly more accurate forecasts than the FMI model. The main reason for the difference is probably due to the optimization of the physical properties of the KNMI model for the Netherlands, whereas the FMI model is designed for ...