 <div class="eI0">
  <div class="eI1">Mod&egrave;le:</div>
  <div class="eI2"><h2>557WW: "557th Weather Wing Ensemble" The US Air Forceâ€™s 557th Weather Wing creates the Global Ensemble Prediction Suite (GEPS) twice per day by ingesting 63 global forecast model runs produced by three operational numerical modeling centers and creating tailored statistical ensemble forecasts. Products include probabilities for precipitation and snowfall, and means/standard deviations of temperature, wind, pressure, height, and relative humidity. 240 hours of one-degree gridded forecast output is produced at 6 hour intervals on the 00Z and 12Z cycle.</h2></div>
 </div>
 <div class="eI0">
  <div class="eI1">Mise &agrave; jour:</div>
  <div class="eI2">2 times per day, from 06:00 and 18:00 UTC</div>
 </div>
 <div class="eI0">
  <div class="eI1">Greenwich Mean Time:</div>
  <div class="eI2">12:00 UTC = 13:00 CET</div>
 </div>
 <div class="eI0">
  <div class="eI1">R&eacute;solution:</div>
  <div class="eI2">1&deg; x 1&deg;</div>
 </div>
 <div class="eI0">
  <div class="eI1">Param&egrave;tre:</div>
  <div class="eI2">Lifted Index</div>
 </div>
 <div class="eI0">
  <div class="eI1">Description:</div>
  <div class="eI2">
<!--begin info text LI-->
<p>
The Lifted Index (LI) is defined as a rising parcel's temperature when it reaches 
the 500 millibars level (at about 5,500m or 18,000 feet asl), subtracted from 
the actual temperature of the environmental air at 500 mbar. If the Lifted 
Index is a large negative number, then the parcel will be much warmer than its 
surroundings, and will continue to rise. Thunderstorms are fueled by strong rising air, thus the 
Lifted Index is a good measurement of the atmosphere's potential to produce 
severe thunderstorms. 
</p>
<p>
<!--begin LI table-->
<body>
<table width="400" cellspacing="0" cellpadding="0" border="0">
  <tr height="30" bgcolor="#E5E5E5"><!-- Row 1 -->
    <td colspan="4"><font size="3" face="Arial, Helvetica" color="#0000FF">The Lifted Index (LI)</td>
  </tr>
  <tr height="30"><!-- Row 2 -->
    <td width="17%" valign="top"><font size="1" face="Arial, Helvetica"><center>RANGE IN K</center></td>
    <td bgcolor="#E5E5E5" width="20%" valign="top"><font size="1" face="Arial, Helvetica"><center>COLOR</center></td>
    <td width="30%" valign="top"><font size="1" face="Arial, Helvetica"><center>AMOUNT OF INSTABILITY</center></td>
    <td widht="33%" valign="top"><font size="1" face="Arial, Helvetica"><center>THUNDERSTORM PROBABILITY</center></td>
  </tr>
  <tr height="25" bgcolor="#E5E5E5"><!-- Row 3 -->
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>more than 11</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica" color="#00A1E6"><center>BLUE</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Extremely stable conditions</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Thunderstorms unlikely</center></td>
  </tr>
  <tr height="25"><!-- Row 4 -->
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>8 to 11</center></td>
    <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#00C7C7"><center>LIGHT BLUE</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Very stable conditions</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Thunderstorms unlikely</center></td>
  </tr>
  <tr height="25" bgcolor="#E5E5E5"><!-- Row 5 -->
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>4 to 7</center></td>
    <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#00D18C"><center>GREEN</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Stable conditions</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Thunderstorms unlikely</center></td>
  </tr>
  <tr height="25"><!-- Row 6 -->
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>0 to 3</center></td>
    <td bgcolor="#E5E5E5"valign="top"><font size="1" face="Arial, Helvetica" color="#A1E633"><center>LIGHT GREEN</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Mostly stable conditions</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Thunderstorm unlikely</center></td>
  </tr>
  <tr height="25" bgcolor="#E5E5E5"><!-- Row 7 -->
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>-3 to -1</center></td>
    <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#E6DC33"><center>YELLOW</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Slightly unstable</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Thunderstorms possible</center></td>
  </tr>
  <tr height="25"><!-- Row 8 -->
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>-5 to -4</center></td>
    <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#F08229"><center>ORANGE</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Unstable</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Thunderstorms probable</center></td>
  </tr>
  <tr height="25" bgcolor="#E5E5E5"><!-- Row 9 -->
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>-7 to -6</center></td>
    <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#F00000"><center>RED</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Highly unstable</center></td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Severe thunderstorms possible</center></td>
  </tr>
  <tr height="25"><!-- Row 10 -->
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>less than -7</td>
    <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#FF00FF"><center>VIOLET</td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Extremely unstable</td>
    <td valign="top"><font size="1" face="Arial, Helvetica"><center>Violent thunderstorms, tornadoes possible</td>
  </tr>
</table>
<!--end LI table-->
</p>
<!--end info_text LI-->

    
  </div>
 </div>
 <div class="eI0">
  <div class="eI1">NWP:</div>
  <div class="eI2">La pr&eacute;vision num&eacute;rique du temps (PNT) est une application de la m&eacute;t&eacute;orologie et de l'informatique. Elle repose sur le choix d'&eacute;quations math&eacute;matiques offrant une proche approximation du comportement de l'atmosph&egrave;re r&eacute;elle. Ces &eacute;quations sont ensuite r&eacute;solues, &agrave; l'aide d'un ordinateur, pour obtenir une simulation acc&eacute;l&eacute;r&eacute;e des &eacute;tats futurs de l'atmosph&egrave;re. Le logiciel mettant en &oelig;uvre cette simulation est appel&eacute; un mod&egrave;le de pr&eacute;vision num&eacute;rique du temps.<br><br>
<br>Pr&eacute;vision num&eacute;rique du temps. (2009, d&eacute;cembre 12). Wikip&eacute;dia, l'encyclop&eacute;die libre. Page consult&eacute;e le 20:48, f&eacute;vrier 9, 2010 &agrave; partir de <a href="http://fr.wikipedia.org/w/index.php?title=Pr%C3%A9vision_num%C3%A9rique_du_temps&oldid=47652746" target="_blank">http://fr.wikipedia.org/w/index.php?title=Pr%C3%A9vision_num%C3%A9rique_du_temps&oldid=47652746</a>.<br>
</div></div>
</div>