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<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" style="" color="#000000">Dear ncl-talk,</font></span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" style="" color="#000000"><br></font></span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" style="" color="#000000">I am getting issues with my ncl script in plotting accumulated precipitation. Basically, I store the 6-hourly precipitation from the grib file and sum it at the end using dim_sum_n. See below snippet of my code. When I use ncl 6.3, the accumulated precipitation increases as expected from hour 6 to hour 144. When I use ncl 6.5, I get certain hours where the precipitation decreases from say hour 18 to hour 24. It only appears to happen when I plot a regional accumulation, though, like for the state of Colorado. But there is nothing different in both scripts. I can't figure out what is going on. Is this a bug?</font></span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000"><br></font></span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000">print("Calculating accumulated precipitation")</font></span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal;min-height:17px"><font face="arial, helvetica, sans-serif" style="background-color:rgb(255,255,255)" color="#000000"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"></span><br></font></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000">accum_pcp = new((/dimsizes(fcst_hr),nlat,nlon/),float)<span class="gmail-Apple-converted-space">  </span>; accumulated precip</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000">accum_pcp!0="hour"</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000">accum_pcp!1="lat"</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000">accum_pcp!2="lon"</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000">accum_pcp&lat = lat</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000">accum_pcp&lon = lon</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000">accum_pcp&lat@units = "degrees_north"</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000">accum_pcp&lon@units = "degrees_east"</font></span></p>
<p class="gmail-p2" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal;min-height:17px"><font face="arial, helvetica, sans-serif" style="background-color:rgb(255,255,255)" color="#000000"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"></span><br></font></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000"><span class="gmail-Apple-converted-space">    </span>ntstrt = 0 ; counter variables for accumulated precipitation</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000"><span class="gmail-Apple-converted-space">    </span>ntlast = 0</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000"><span class="gmail-Apple-converted-space">    </span>do t=0,dimsizes(fcst_hr)-1</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000"><span class="gmail-Apple-converted-space">    </span>accum_pcp(t,:,:) = dim_sum_n(saved_pcp(ntstrt:ntlast,:,:),0)</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" color="#000000"><span class="gmail-Apple-converted-space">    </span>ntlast = ntlast + 1 <span class="gmail-Apple-converted-space">  </span>; increment for accumulated precipitation</font></span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" style="" color="#000000"><span class="gmail-Apple-converted-space" style="">    </span>end do</font></span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures;background-color:rgb(255,255,255)"><font face="arial, helvetica, sans-serif" style="" color="#000000"><br></font></span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;line-height:normal"><font color="#000000" face="arial, helvetica, sans-serif"><span style="font-variant-ligatures:no-common-ligatures">Thank you,</span></font></p><div><br></div>-- <br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr">Andrew Kren<br>Assistant Scientist<br>University of Miami CIMAS - NOAA/AOML</div><div dir="ltr">Duty Station: NCAR Foothills - FL2-3058</div><div>Boulder, Colorado, USA</div><div dir="ltr">Office: 303-497-2715</div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div>