Wim Van den Berg

DTN · Forecast Team

This paper (in Dutch), published in Meteorologica 3-2019, describes how numerical models and forecasters anticipated the record breaking July 2019 heatwave in the Netherlands. Emphasis gets the unprecedented 40C, that was also kind of "psychological barrier" for the forecasters who were very keen on not announcing the 40C before this was quite cert...

Regional weather forecasting models like the Weather Research and Forecasting (WRF) model allow for nested domains to save computational effort and still provide detailed results for mesoscale weather phenomena. The sudden resolution change by nesting can may cause artefacts in the model results. On the contrary, The the novel global Model for Pred...

Consumer weather stations, submiiting data to related websites, bring a challenge to the meteorological community used to WMO station quality and siting. Sensors may be of less quality, are not maintained properly, and can be sited close to buildings. However, the additional amount of weather observations is huge, and the update frequency every 10...

First, we evaluate MPAS for a number of key synoptic situations over Europe using several meshes with various refinement ratios and a uniform 3km mesh as reference. We compare this to the operational WRF setup of MeteoGroup Netherlands. The WRF model performs very similar to the observations in all cases, as does the global 3km MPAS run. The variab...

The new Model for Prediction Across Scales (MPAS) applies an irregular grid to avoid boundary condition problems with regional nested models like WRF. In this study, presented at EGU 2017, we compare MPAS results with WRF 3km for three extreme weather cases in Europe.

Regional models like the Weather Research and Forecasting (WRF) model use nested domains to save computational effort. However, studies have shown that sudden resolution changes between the nests can cause artefacts. The novel global Model for Prediction Across Scales (MPAS) runs on Voronoi meshes that allow for a smooth resolution transition towar...

Rich Water World an adaptive water management tool based on weather forecasting, sensor data and hydrological modelling. Climate change will cause periods of more extreme rainfall relieved by periods of drought. Water systems have to become more robust and self supporting in order to prevent damage by flooding and drought. For climate proof water m...

Extreme weather situations as droughts and extensive precipitation are becoming more frequent, which makes it more important to obtain accurate weather forecasts for the short and long term. Ensembles can provide a solution in terms of scenario forecasts. MeteoGroup uses ensembles in a new forecasting technique which presents a number of weather sc...

At MeteoGroup a long, quality controlled, gap-filled, station database has been created. The database contains long time series of various atmospheric parameters for about 20,000 stations worldwide. Currently, most climate analyses are carried out with an atmospheric model (e.g. ERA-40, CFSR etc.) in order to generate a spatially and temporally hom...

Society is vulnerable for extreme weather events. Especially the simultaneous occurrence of multiple weather variable may lead to hazards. Examples are high astronomical tides and surges for sea dikes, and snow melt and precipitation for river discharges. Here we highlight the probability of the simultaneous occurrence of high wind speeds and extre...

At Meteo Consult, part of MeteoGroup, ECMWF model data is pre-and post processed making extensive use of various observation types. Three applications will be shown. (1) Precipitation nowcasts, including precipitation type nowcasts, based on a combination of radar and SYNOP observations and Model Output Statistics (MOS). (2) Results of the Automati...

Frictional convergence and thermal difference between land and sea surface are the two surface conditions that govern the intensity and evolution of a coastal front. By means of the mesoscale model MM5, we investigate the influence of these two processes on wind patterns, temperature and precipitation amounts, associated with a coastal front, obser...

Paper in Dutch. Based on the book "Säntiswetter - Freuden und Leiden der Wetterwarte1880-1970" by Bruno Meier, Appenzeller Verlag, 1997, ISBN 3-85882-099-7

Includes foreword and summary in English. Thesis (doctoral)--Rijksuniversiteit te Utrecht, 1987. Includes bibliographical references (p. 230-238).

The coastline generally represents it marked discontinuity in surface roughness. The resulting mechanical forcing leads to a secondary circulation in the boundary layer, and consequently to a vertical motion field that may have a strong influence on the weather in the coastal zone. In potentially unstable air masses, frictional convergence may caus...

Evapotranspiration is calculated from surface temperatures using an energy balance method. This method is sensitive to the temperature difference between the surface and the air above, and somewhat to the windspeed. In this study we consider the influence of the spatial variability of air temperature on the interpretation of surface temperatures.It...

A Fourier technique is described by which it is possible to filter away tidal oscillations and synoptic scale variations from hourly pressure data. The method clearly reveals four solar tidal components, that are present in the surface pressure data of Dutch stations in November. At the lightvessel “Noordhinder” an additional component is present d...