<div class="eI0"> <div class="eI1">Model:</div> <div class="eI2"><h2>Times Series from the NCEP</h2></div> </div> <div class="eI0"> <div class="eI1">Ververst:</div> <div class="eI2">Update monthly</div> </div> <div class="eI0"> <div class="eI1">Greenwich Mean Time:</div> <div class="eI2">12:00 UTC = 14:00 MEZT</div> </div> <div class="eI0"> <div class="eI1">Resolutie:</div> <div class="eI2">1.0° x 1.0°</div> </div> <div class="eI0"> <div class="eI1">Parameter:</div> <div class="eI2">Lift-index</div> </div> <div class="eI0"> <div class="eI1">Beschrijving:</div> <div class="eI2"> <!--begin info text LI--> <p> De Lift-index (ook wel 'stijgingsindex') is de temperatuur op het 500 hectopascal - vlak (gemiddeld is dat op ongeveer 5500 meter hoogte, of 18.000 voet boven zeeniveau), minus de temperatuur van een opstijgend luchtdeeltje vanaf de grond op dit luchtdrukniveau. Als de Lift-Index (sterk) negatief is dan geeft het aan dat een luchtdeeltje (veel) warmer is dan zijn omgeving, en het luchtdeeltje zal blijven stijgen. Omdat onweerswolken gevoed worden door sterk stijgende luchtstromen is de Lift-Index een goede indicatie voor de kans op de ontwikkeling van (zware) onweersbuien. </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">De Lift Index (LI)</td> </tr> <tr height="30"><!-- Row 2 --> <td width="17%" valign="top"><font size="1" face="Arial, Helvetica"><center>Schaal in K</center></td> <td bgcolor="#E5E5E5" width="20%" valign="top"><font size="1" face="Arial, Helvetica"><center>Kleur</center></td> <td width="30%" valign="top"><font size="1" face="Arial, Helvetica"><center>Mate van onstabiliteit</center></td> <td widht="33%" valign="top"><font size="1" face="Arial, Helvetica"><center>Kans op Onweer</center></td> </tr> <tr height="25" bgcolor="#E5E5E5"><!-- Row 3 --> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Meer dan 11</center></td> <td valign="top"><font size="1" face="Arial, Helvetica" color="#00A1E6"><center>Blauw</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Extreem stabiel</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Vrijwel uitgesloten</center></td> </tr> <tr height="25"><!-- Row 4 --> <td valign="top"><font size="1" face="Arial, Helvetica"><center>8 tot 11</center></td> <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#00C7C7"><center>Licht blauw</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Zeer stabiel</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Vrijwel uitgesloten</center></td> </tr> <tr height="25" bgcolor="#E5E5E5"><!-- Row 5 --> <td valign="top"><font size="1" face="Arial, Helvetica"><center>4 tot 7</center></td> <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#00D18C"><center>Groen</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Stabiel</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Vrijwel uitgesloten</center></td> </tr> <tr height="25"><!-- Row 6 --> <td valign="top"><font size="1" face="Arial, Helvetica"><center>0 tot 3</center></td> <td bgcolor="#E5E5E5"valign="top"><font size="1" face="Arial, Helvetica" color="#A1E633"><center>Licht groen</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Relatief stabiel</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Klein</center></td> </tr> <tr height="25" bgcolor="#E5E5E5"><!-- Row 7 --> <td valign="top"><font size="1" face="Arial, Helvetica"><center>-3 tot -1</center></td> <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#E6DC33"><center>Geel</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Licht onstabiel</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Mogelijk</center></td> </tr> <tr height="25"><!-- Row 8 --> <td valign="top"><font size="1" face="Arial, Helvetica"><center>-5 tot -4</center></td> <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#F08229"><center>Oranje</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Onstabiel</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Groot</center></td> </tr> <tr height="25" bgcolor="#E5E5E5"><!-- Row 9 --> <td valign="top"><font size="1" face="Arial, Helvetica"><center>-7 tot -6</center></td> <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#F00000"><center>Rood</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Zeer onstabiel</center></td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Zwaar onweer mogelijk</center></td> </tr> <tr height="25"><!-- Row 10 --> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Minder dan -7</td> <td bgcolor="#E5E5E5" valign="top"><font size="1" face="Arial, Helvetica" color="#FF00FF"><center>Pars</td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Extreem onstabiel</td> <td valign="top"><font size="1" face="Arial, Helvetica"><center>Zwaar onweer en windhozen mogelijk</td> </tr> </table> <!--end LI table--> </p> <!--end info_text LI--> </div> </div> <div class="eI0"> <div class="eI1">NWP:</div> <div class="eI2">Numerical weather prediction uses current weather conditions as input into mathematical models of the atmosphere to predict the weather. Although the first efforts to accomplish this were done in the 1920s, it wasn't until the advent of the computer and computer simulation that it was feasible to do in real-time. Manipulating the huge datasets and performing the complex calculations necessary to do this on a resolution fine enough to make the results useful requires the use of some of the most powerful supercomputers in the world. A number of forecast models, both global and regional in scale, are run to help create forecasts for nations worldwide. Use of model ensemble forecasts helps to define the forecast uncertainty and extend weather forecasting farther into the future than would otherwise be possible.<br> <br>Wikipedia, Numerical weather prediction, <a href="http://en.wikipedia.org/wiki/Numerical_weather_prediction" target="_blank">http://en.wikipedia.org/wiki/Numerical_weather_prediction</a>(as of Feb. 9, 2010, 20:50 UTC).<br> </div></div> </div>