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<div>Thanks for the response Jeff - it’s strange to me as well!</div>
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<div>Running wgrib2 on the data files for forecast hours 001 through 007 gives the following for TCDCclm:</div>
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<div><b>f001:</b></div>
<div>17:7991683:d=2016110212:TCDC:entire atmosphere:<b>0-1</b> hour ave fcst:</div>
<div><b>f002:</b></div>
<div>17:8082626:d=2016110212:TCDC:entire atmosphere:<b>0-2</b> hour ave fcst:</div>
<div><b>f003:</b></div>
<div>17:8059826:d=2016110212:TCDC:entire atmosphere:<b>0-3 </b>hour ave fcst:</div>
<div><b>f004:</b></div>
<div>17:8057865:d=2016110212:TCDC:entire atmosphere:<b>0-4</b> hour ave fcst:</div>
<div><b>f005:</b></div>
<div>17:8119289:d=2016110212:TCDC:entire atmosphere:<b>0-5</b> hour ave fcst:</div>
<div><b>f006:</b></div>
<div>17:8172510:d=2016110212:TCDC:entire atmosphere:<b>0-6</b> hour ave fcst:</div>
<div><b>f007:</b></div>
<div>17:8013825:d=2016110212:TCDC:entire atmosphere:<b>6-7</b> hour ave fcst:</div>
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<div>And it continues on..once the files go to 3 hourly (after hour 120), we have:</div>
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<div><b>f123:</b></div>
<div>17:7687687:d=2016110212:TCDC:entire atmosphere:<b>120-123</b> hour ave fcst:</div>
<div><b>f126:</b></div>
<div>17:7778871:d=2016110212:TCDC:entire atmosphere:<b>120-126</b> hour ave fcst:</div>
<div><b>f129:</b></div>
<div>17:7728042:d=2016110212:TCDC:entire atmosphere:<b>126-129</b> hour ave fcst:</div>
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<div>And finally the 12 hourly files (past hour 240) are all just 12 hour average forecasts:</div>
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<div><b>f252:</b></div>
<div>17:6845416:d=2016110212:TCDC:entire atmosphere:<b>240-252</b> hour ave fcst:</div>
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<div>I did think about the method you suggested (tcdcclm - tcdcclm(t-1)) but stopped there for the reason you mentioned..</div>
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<div>Strange indeed - unless I’m missing something..</div>
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<div>Thanks,</div>
<div>Sam</div>
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<span style="font-weight:bold">From: </span><<a href="mailto:gradsusr-bounces@gradsusr.org">gradsusr-bounces@gradsusr.org</a>> on behalf of Jeff Duda <<a href="mailto:jeffduda319@gmail.com">jeffduda319@gmail.com</a>><br>
<span style="font-weight:bold">Reply-To: </span>GrADS Users Forum <<a href="mailto:gradsusr@gradsusr.org">gradsusr@gradsusr.org</a>><br>
<span style="font-weight:bold">Date: </span>Wednesday, November 2, 2016 at 2:08 PM<br>
<span style="font-weight:bold">To: </span>GrADS Users Forum <<a href="mailto:gradsusr@gradsusr.org">gradsusr@gradsusr.org</a>><br>
<span style="font-weight:bold">Subject: </span>Re: [gradsusr] GFS total cloud cover<br>
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<div>It seems a little strange to me that the total cloud cover product would be averaged over time. Is that really the case?<br>
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Anyway, if you really do have an average over overlapping and increasing windows, with nothing else to go on and without applying the equations of motion in reverse, you'd have to assume a linear averaging, so subtraction of subsequent slices of the field (i.e.,
tcdcclm - tcdcclm(t-1)) would give you piecewise temporal averages. However, that method would give you negative cloud cover values which is clearly nonsensical, which again is why I question whether or not that array contains a temporal average. That just
doesn't make a lot of sense.<br>
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Jeff Duda<br>
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<div class="gmail_quote">On Wed, Nov 2, 2016 at 3:27 PM, Sam Wilson <span dir="ltr">
<<a href="mailto:sam@surfline.com" target="_blank">sam@surfline.com</a>></span> wrote:<br>
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<div>Hi,</div>
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<div>I’m working with hourly GFS total cloud cover (TCDCclm) and I’m a bit stumped on the following..</div>
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<div>Given TCDCclm for hours 0-1, 0-2, 0-3, 0-4, 0-5, and 0-6, what is the proper way to determine TCDCclm for hours 1-2, 2-3, 3-4, 4-5, and 5-6?</div>
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<div>I may be making the problem more difficult than it is..but wanted to ping this group to be sure.</div>
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<div>Is there an existing grads script that handles this already and if not, does anyone here have any insight?</div>
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<div>Thanks so much for your time.</div>
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<div>Best,</div>
<div>Sam</div>
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-- <br>
<div class="gmail_signature" data-smartmail="gmail_signature">
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<div>Jeff Duda<br>
Post-doctoral research associate<br>
University of Oklahoma School of Meteorology<br>
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