<div dir="ltr">Anyone have any ideas for calculating a field which contains the -20C isotherm heights in meters?<div><br></div><div>I have thought of a few ways, but they are only giving me pressure levels. I tried using the fndlvl function:</div><div><br></div><div>define m20lev = fndlvl (tmpprs, const(tmpprs,253.15), z=1, z=80) </div><div><br></div><div>This just gives me the pressure levels of the -20C isotherm. I suppose I could use teh hypsometric equation after using the fndlvl function. <br><br>I also thought of using the <a href="http://zinterp.gs">zinterp.gs</a> script, but again, this wants me to input the pressure level to interpolate to heights. My pressure levels vary, so this will not work. I fell like I'm missing something really obvious, but I can't put my finger on it.<br clear="all"><div><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><b>-------</b></div>William (L.B.) LaForce<br>Meteorologist<div><a href="http://www.tornadoinsanity.com" target="_blank">www.tornadoinsanity.com</a></div></div></div></div></div></div>
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