Nowcasting SAF Products
Some text on NWCSAF and the products that will be discussed and the advantager that these have.
Cloud Mask
The cloud mask (CMa), aims to support nowcasting applications and additionally the remote-sensing of continental and oceanic surfaces. The CMa allows identifying cloud free areas where other products (total or layer precipitable water, land or sea surface temperatures) may be computed. It also allows identifying cloudy areas where other products (cloud types and cloud top temperature/height) may be derived.
Cloud Type
The cloud type (CT), developed within the SAF NWC context, mainly aims to support nowcasting applications. The main objective of this product is to provide a detailed cloud analysis. It may be used as input to an objective meso-scale analysis (which in turn may feed a simple nowcasting scheme), as an intermediate product input to other products, or as a final image product for display at a forecaster 's desk. The CT product is essential for the generation of the cloud top temperature and height product and for the identification of precipitation clouds. Finally, it is also essential for the computation of radiative fluxes over sea or land, which are SAF Ocean and Sea Ice products.
The aim ASII and ASII-NWP as SAFNWC products is the Automatic Satellite Image Interpretation in terms of conceptual models (CM). CMs are a synthesis of physical processes and the typical features they cause in satellite images, as well as in other synoptic material like for instance in numerical model output parameters. A CM diagnosis can be used for a deepening of synoptic diagnosis and for the early detection of ongoing meteorological processes, as well as for the determination of the stage of development within those processes.
ASII
Automatic Satellite Image Interpretation from MSG SEVIRI satellite data alone
ASII NWP
Automatic Satellite Image Interpretation from MSG SEVIRI satellite data supplemented by typical key parameters from the numerical model output (Numerical model used: ECMWF)
Airmass Analysis
Evaluates basic quantities describing air masses (upper and middle level humidity, mean temperature, atmospheric stability, cloud pattern, etc) to combine them into one integrated classification of the air mass.
Precipitating Clouds
The objective of the PC product is to support detailed precipitation analysis for nowcasting purposes. The focus is on the delineation of non-precipitating and precipitating clouds for light and heavy precipitation, rather than quantifying the precipitation rate. Particular attention will be given to the identification of areas of light frontal precipitation.
The product provides probability results, i.e. probabilities of precipitation intensities in pre-defined intensity intervals. From the probabilities a categorical estimate of precipitation intensity may be derived. It is not intended to provide information on the type of precipitation.