<div class="eI0">
  <div class="eI1">Modelo:</div>
  <div class="eI2"><h2><a href="http://www.metoffice.gov.uk" target="_blank">Euro4</a>: Global weather forecast model from the "UK MetOffice, North Atlantic European Model"</h2></div>
 </div>
 <div class="eI0">
  <div class="eI1">Actualiza&ccedil;&atilde;o:</div>
  <div class="eI2">4 times per day, from 0:00, 05:00, 11:00 and 17:00 UTC</div>
 </div>
 <div class="eI0">
  <div class="eI1">Greenwich Mean Time:</div>
  <div class="eI2">12:00 UTC = 12:00 WET</div>
 </div>
 <div class="eI0">
  <div class="eI1">Resolution:</div>
  <div class="eI2">0.04&deg; x 0.04&deg;</div>
 </div>
 <div class="eI0">
  <div class="eI1">par&acirc;metro:</div>
  <div class="eI2">CAPE and vertical velocity at 700 hPa</div>
 </div>
 <div class="eI0">
  <div class="eI1">Descri&ccedil;&atilde;o:</div>
  <div class="eI2">
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.
<BR>
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). 
<BR>
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 <a href="/cgi-bin/expertcharts?LANG=nz&MENU=0000000000&CONT=euro&MODELL=temps&MODELLTYP=4&BASE=-&VAR=temps&LKEY=UK&HH=6&ARCHIV=0&SHOW=1">skew-T thermodynamic diagram</a> at that location may indicate 500-1500 J/kg.
(Source: <a href="http://www.lightningwizard.com" target="_blank">The Lightning Wizard</a>)
<BR>
Table 1: Characteristic values for CAPE<BR>
<TABLE border=1>
<TR>
   <TD><STRONG>CAPE value</STRONG></TD>

   <TD><STRONG>Convective potential</STRONG></TD>
</TR>
<TR>
   <TD>0 </TD>
   <TD>Stable</TD>
</TR>
<TR>
   <TD>0-1000</TD>
   <TD>Marginally Unstable</TD>

</TR>
<TR>
   <TD>1000-2500</TD>
   <TD>Moderately Unstable</TD>
</TR>
<TR>
   <TD>2500-3500</TD>
   <TD>Very Unstable</TD>
</TR>

<TR>
	<TD> 3500 + </TD>
	<TD> Extremely Unstable </TD>
<TR>
</TABLE> 

    
  </div>
 </div>
 <div class="eI0">
  <div class="eI1">NWP:</div>
  <div class="eI2">A previs&atilde;o num&eacute;rica do tempo usa o estado instant&acirc;neo da atmosfera como dados de entrada para modelos matem&aacute;ticos da atmosfera, com vista &agrave; previs&atilde;o do estado do tempo.<br>
Apesar dos primeiros esforços para conseguir prever o tempo tivessem sido dados na d&eacute;cada de 1920, foi apenas com o advento da era dos computadores que foi possível realiz&aacute;-lo em tempo real. A manipulaç&atilde;o de grandes conjuntos de dados e a realizaç&atilde;o de c&aacute;lculos complexos para o conseguir com uma resoluç&atilde;o suficientemente elevada para produzir resultados úteis requer o uso dos supercomputadores mais potentes do mundo. Um conjunto de modelos de previs&atilde;o, quer &agrave; escala global quer &agrave; escala regional, s&atilde;o executados para criar previsões do tempo nacionais. O uso de previsões com modelos semelhantes ("model ensembles") ajuda a definir a incerteza da previs&atilde;o e estender a previs&atilde;o do tempo bastante mais no futuro, o que n&atilde;o seria possível conseguir de outro modo.<br>
<br>Contribuidores da Wikip&eacute;dia, "Previs&atilde;o num&eacute;rica do tempo," Wikip&eacute;dia, a enciclop&eacute;dia livre, <a href="http://pt.wikipedia.org/w/index.php?title=Previs%C3%A3o_num%C3%A9rica_do_tempo&amp;oldid=17351675" target="_blank">http://pt.wikipedia.org/w/index.php?title=Previs%C3%A3o_num%C3%A9rica_do_tempo&oldid=17351675</a> (accessed fevereiro 9, 2010). <br>
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