Modèle:

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

Mise à jour:
2 times per day, from 00:00 and 12:00 UTC
Greenwich Mean Time:
12:00 UTC = 14:00 CEST
Résolution:
0.02° x 0.02°
Paramètre:
CAPE and vertical velocity at 700 hPa
Description:
The Convectively Available Potential Energy (CAPE) map - updated every 6 hours - shows the modelled convectively available potential energy. CAPE represents the amount of buoyant energy (J/kg) available to accelerate a parcel vertically, or the amount of work a parcel does on the environment. The higher the CAPE value, the more energy available to foster storm growth. The potential energy can be converted to kinetic energy reflected in upward motion.
It should be remembered that CAPE represents potential energy, and will only be used should a parcel be lifted to the level of free convection. When values are above 3500 j/kg and storms do develop, they may build rapidly and quickly become severe. Often these storms are referred to as "explosive storms" by chasers and professionals. In a high CAPE environment storms that develop can usually be seen by the human eye as rising rapidly. Higher CAPE typically involves stronger storms with a higher chance of large hail and other severe weather. Note that CAPE is usually of lesser importance than the vertical shear environment for tornadoes. The probability of large hail increases with CAPE, given at least moderate shear(values around 500-1000 J/kg are sufficient).
CAPE is very sensitive to small differences in the moisture and temperature profiles. While the maps indicate 1000 J/kg CAPE at some location, a skew-T thermodynamic diagram at that location may indicate 500-1500 J/kg. (Source: The Lightning Wizard)
Table 1: Characteristic values for CAPE
CAPE value Convective potential
0 Stable
0-1000 Marginally Unstable
1000-2500 Moderately Unstable
2500-3500 Very Unstable
3500 + Extremely Unstable
ICON-D2:
ICON-D2 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.