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<p class="MsoPlainText">All - <o:p></o:p></p>
<p class="MsoPlainText">I'm generating some post-processed information based off an ensemble. So for example, I might be generating the following parameters:<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:240-246 hour acc fcst:prob >2:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:240-246 hour acc fcst:prob >4:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:234-246 hour acc fcst:prob >4:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:234-246 hour acc fcst:prob >6:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:222-246 hour acc fcst:prob >2:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:222-246 hour acc fcst:prob >6:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText">…and I’m writing these fields in GriB2 format. In this example, I’m generating the data off of the GFS ensemble, writing out the information every 6 hours, with data valid at that forecast hour. So the above records appear in the
246 hour forecast file.<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Note that we have a couple of fields then that, when using g2ctl, or even alt_g2ctl, would have identical variable names as they only differ in the accumulation period –<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:240-246 hour acc fcst:prob >2:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:222-246 hour acc fcst:prob >2:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:240-246 hour acc fcst:prob >4:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:234-246 hour acc fcst:prob >4:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:234-246 hour acc fcst:prob >6:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW Total Snowfall [prob]:surface:222-246 hour acc fcst:prob >6:probability forecast<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><o:p> </o:p></p>
<p class="MsoPlainText">The g2ctl utility outputs the following entries into the control file:<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW2e3GTsfc 0,1,0 a1,2 0,1,29,1 ** surface prob >2 Total Snowfall [prob]<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW4e3GTsfc 0,1,0 a1,4 0,1,29,1 ** surface prob >4 Total Snowfall [prob]<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOW6e3GTsfc 0,1,0 a1,6 0,1,29,1 ** surface prob >6 Total Snowfall [prob]</span><o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">The alt_gt2ctl:<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOWdprob_>2dprobability_forecastsfc 0 0 "ASNOW.prob_>2.probability_forecast:surface" * ASNOW.prob_>2.probability_forecast:surface<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOWdprob_>4dprobability_forecastsfc 0 0 "ASNOW.prob_>4.probability_forecast:surface" * ASNOW.prob_>4.probability_forecast:surface<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">ASNOWdprob_>6dprobability_forecastsfc 0 0 "ASNOW.prob_>6.probability_forecast:surface" * ASNOW.prob_>6.probability_forecast:surface<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoPlainText">…and alt_g2ctl using the “–short” flag:<o:p></o:p></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">v1 0 0 "ASNOW.prob_>2.probability_forecast:surface"<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">v2 0 0 "ASNOW.prob_>4.probability_forecast:surface"<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:9.0pt;font-family:"Courier New"">v3 0 0 "ASNOW.prob_>6.probability_forecast:surface"<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:.5in"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoPlainText">My problem is that I’m unsure how to reference the different accumulation periods for the given parameters. If I were to create a template for a 246 hour forecast period, and within the GrADS command line interface, input “set t=42”,
and try to display one of the above parameters, how do I know which one I’m displaying and how does one switch to a different accumulation period? I’m hoping to avoid creating new files containing subsets of the above data, but at the moment I’m not sure
how to work around it. Is there a way to give each accumulation period a unique ID or an appropriate mechanism for identifying differing accumulation periods for a given parameter?<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Thanks!<o:p></o:p></p>
<p class="MsoPlainText">Scott<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">//Signed//<o:p></o:p></p>
<p class="MsoPlainText">Scott Rentschler, Meteorologist<o:p></o:p></p>
<p class="MsoPlainText">Fine Scale / Ensemble Models Team<o:p></o:p></p>
<p class="MsoPlainText">557th Weather Wing, 16WS/WXN<o:p></o:p></p>
<p class="MsoPlainText">DS: 271-3331 Comm: (402) 294-3331<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
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