Modèle:

ICON(ICOsahedral Nonhydrostatic general circulation model) from the German Weather Service

Mise à jour:
4 times per day, from 08:00, 14:00, 20:00, and 00:00 UTC
Greenwich Mean Time:
12:00 UTC = 13:00 CET
Résolution:
0.125° x 0.125°
Paramètre:
Geopotential in 850 hPa (solid, black lines) and Vorticity advection in 105/(s*6h) (colored lines)
Description:
The two types of vorticity advection are positive (PVA) and negative vorticity advection (NVA). The closed circles in the figure show the 850 hPa absolute vorticity lines, the others the 850 hPa height lines. When an air parcel is moving from an area higher vorticity to an area lower vorticity this is called: PVA (red color). The other way around is called: NVA (blue color). PVA is associated with upper-air divergence, i.e. upward vertical motion. NVA is associated with down ward vertical motion. Therefore, PVA  at 500 hPa is strongest above a surface low, while NVA at 500 hPa is strongest above a surface high.
In operational meteorology Vorticity advection maps are used to identify areas with vertical air motion to see where clouds, precipitation or clear conditions are likely to occur. Keep in mind, however, that PVA is not the same as upward vertical motion. Here temperature advection is important too.
ICON:
ICON The ICON dynamical core is a development initiated by the Max Planck Institute for Meteorology (MPI-M) and the Opens external link in current windowGermany Weather Service (DWD). This dynamical core is designed to better tap the potential of new generations of high performance computing, to better represent fluid conservation properties that are increasingly important for modelling the Earth system, to provide a more consistent basis for coupling the atmosphere and ocean and for representing subgrid-scale heterogeneity over land, and to allow regionalization and limited area implementations.
NWP:
La prévision numérique du temps (PNT) est une application de la météorologie et de l'informatique. Elle repose sur le choix d'équations mathématiques offrant une proche approximation du comportement de l'atmosphère réelle. Ces équations sont ensuite résolues, à l'aide d'un ordinateur, pour obtenir une simulation accélérée des états futurs de l'atmosphère. Le logiciel mettant en œuvre cette simulation est appelé un modèle de prévision numérique du temps.


Prévision numérique du temps. (2009, décembre 12). Wikipédia, l'encyclopédie libre. Page consultée le 20:48, février 9, 2010 à partir de http://fr.wikipedia.org/w/index.php?title=Pr%C3%A9vision_num%C3%A9rique_du_temps&oldid=47652746.