Weather Model Theory
meteoblue weather models are based on the NMM (Nonhydrostatic Meso-Scale Modelling) technology.
Model calculations are done for “domains” - large areas covering parts of (or even entire) continents, for which a complete forecast is calculated. Domains are embedded in larger scale global models (such as NEMS30), which provide the “boundary” conditions (e.g. the air currents coming into or moving out of the domain area) for the days of the forecast. Since 2013 meteoblue computes its own global weather forecast and thus can generate the boundary conditions on its own.
Each domain is divided into grid cells which are rectangularly arranged and evenly spaced between each other. The average distance between the grid centres (grid points) is the “spatial resolution”, which varies from 30 km down to 1 km. Domains typically have 55 atmospheric levels, which range from the surface to approximately 14 kilometres height.
Each grid cell has its own position, altitude, exposition, land surface type and boundary conditions. The altitude is defined using the median altitude of the grid cell area, as taken from high resolution land surface models (~100 m).
This approach allows calculation of the weather specifically for each area, with uniform, high quality for distinct locations ranging from city centres over airports to distant mountain areas, and provides a unique weather forecast quality and consistency.
With the introduction of a global and several continental NMM models, meteoblue has established itself as the private producer with the largest volume of weather forecast data since 2007. No other private supplier in Europe covers as much area in the same detail as meteoblue.
meteoblue is also the first worldwide provider to daily produce hourly weather forecasts in spatial resolution of less than 20 km for large parts of Africa, entire South America and South East Asia since 2008, the first worldwide provider to operate an hourly global weather forecast since 2013, and the first to offer a 30-year global hourly weather history beginning in 1984.
NMM modelling developments
NMM technology has been developed and used for weather forecasting in North America by NOAA and for hurricane prediction. More recent developments include the NEMS framework (NOAA Environmental Modeling System) which has been adapted and further developed to allow global and regional high resolution modelling, seamless nesting for regional domains and improved cloud and precipitation schemes.
meteoblue does not use WRF and other open source models, as they produce significantly different results. Main improvements of NMM and NEMS models relative to WRF are cloud and precipitation schemes, radiation simulation, domain nesting and global scalability and many adaptations to high resolution.