Integrated Nowcasting through Comprehensive Analysis

from Wikipedia, the free encyclopedia

Integrated Nowcasting through Comprehensive Analysis (also called INCA for short) is an Austrian weather model for weather analysis and forecasting in the nowcasting area with special consideration of regional and small-scale topographical effects (Alpine region).

Properties and development

The analysis and nowcasting system INCA is in operational use after about two years of development by ZAMG . The development of the system is ongoing. Improvements and expansions are continuously being carried out, including with regard to the emergence and development of convective weather events. Successor models with an even more refined resolution are also being planned.

With a resolution of 1 kilometer for Austria and the surrounding area, the weather model provides an hourly interpolated analysis or forecast of temperature, humidity, wind, cloud cover and precipitation.

Among other things, numerical weather forecast models ( ALADIN , ECMWF ) are combined with current measured values ​​( TAWES station data , radar , weather satellite data ) and refined with the help of high-resolution terrain information. The goal is to get high quality and reliable analysis and prognosis of the current atmospheric condition, especially in the Alpine region.

Methodology and application

For those meteorological fields that are three-dimensionally analyzed and forecast in INCA, the calculation process is divided into the following steps:

  • Interpolation of the forecast of the ALADIN weather forecast model on the INCA computing grid. A vertical extrapolation algorithm specially developed for this purpose also assigns realistic values ​​to those Alpine valleys that are not sufficiently resolved in ALADIN. Station data are algorithmically combined with remote sensing data (satellite data for cloud cover, radar for precipitation). This combination makes use of the greater quantitative accuracy of the station data and the better spatial resolution of the remote sensing data. The resulting analysis reproduces the values ​​measured at the station points and shows the structures contained in the remote sensing data between the stations.
  • The differences between the first interpolation and the current observation are formed at the measuring stations and these are interpolated again in three dimensions. When weighting the stations in the interpolation, both their spatial distance and the stability of the atmosphere play a role. The resulting difference field is added as a correction to the "first guess". The result is the INCA analysis. In the case of the wind field, an algorithm is also used that adapts the wind field to the high-resolution topography in INCA. Displacement vectors are determined from successive analyzes using correlation methods. With the help of these vectors, the position of the cloud cover or the precipitation in the next few hours is estimated.
  • The difference field calculated in the analysis is also used for the correction of the ALADIN prognosis for the next few hours, with the weight decreasing over time. The temperature forecast also takes into account and compensates for the effect of errors in the ALADIN cloud forecast (e.g. unrecognized high fog).

The verification of the INCA forecasts shows that the system delivers significantly improved forecast values ​​for the next 2–6 hours (depending on the weather situation) and is therefore an important source of information for the weather report , but especially for weather warnings .

INCA is used in flood warning and forecasting, and together with the SNOWGRID model for the snow situation . It also proves its worth in specific event weather, such as sports and open-air events.

The INCA analyzes are available free of charge to the public on the ZAMG homepage and form the basis for applications (such as Internet portals) with spatially and temporally detailed meteorological information. Special short-term forecasts and severe weather warnings are offered as a commercial service.

See also

Web links

  • Current analysis: temperature, precipitation, wind, gusts, clouds, thunderstorms, total snow, 24h difference in total snow. ZAMG.

proof

  • INCA , zamg.ac.at / Research / Weather
  • Austrian hail insurance : Hagelversicherung and ZAMG (Central Institute for Meteorology and Geodynamics): Weather service for agriculture. In: Bauernjournal , August 1, 2012, V ( pdf , hagel.at)
  1. ↑ a b cf. Supervision of major events. zamg.ac.at