<div dir="ltr"><div dir="ltr">The wrf_user_intrp3d does not do extrapolation below ground, so you're seeing the fill values there. You need to use the wrf_user_vert_interp function for this (<a href="https://www.ncl.ucar.edu/Document/Functions/WRF_arw/wrf_user_vert_interp.shtml">https://www.ncl.ucar.edu/Document/Functions/WRF_arw/wrf_user_vert_interp.shtml</a>). Note however that if you use this function with pressure as your field variable and height as your vertical coordinate, the values in the extrapolated region will be in the wrong units of hPa (currently working on a fix for this). In your case, where pressure is your vertical coordinate, you should be fine.</div><div dir="ltr"><br></div><div>Hope this helps,</div><div><br></div><div>Bill</div></div><br><div class="gmail_quote"><div dir="ltr">On Tue, Oct 9, 2018 at 3:35 PM Daniel Vecellio <<a href="mailto:djvecellio@tamu.edu">djvecellio@tamu.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">All,<div><br></div><div>I'm attempting to extrapolate heights down to 1000mb over my domain in order to calculate 1000-500mb thickness. However, at some of my higher elevations where pressure only gets to 800mb or so at the surface, the extrapolation in the wrf_user_intrp3d function becomes wonky, and I get values that are 9.9e+36 for 1000mb height. </div><div><br></div><div>The line of code I use is: z_1000 = wrf_user_intrp3d(z,p,"h",1000.,0.,False) where z and p are height and pressure obtain from wrf_user_getvar</div><div><br></div><div>Is there a way to provide reasonable numbers here? Given that we have perfectly fine operational thickness maps over the Rockies, it has to be possible, right?</div><div><br></div><div>Thanks in advance,</div><div>Dan</div></div>
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