<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; ">Dear Michael --<DIV>With grib1, a record contained a single 2D grid. But with grib2, a record can contain more then one 2D grid -- which are now referred to as 'fields'. NCEP is packaging U and V fields into a single record; other data providers are rumored to be putting ALL fields into a single grib2 record. It's more economical (fields can share metadata this way), but it makes grib2 a bit more complex than grib1. I haven't used the degrib program, but there must be a way to specify which field you want to extract... You could also try Wesley's wgrib2 program.</DIV><DIV>Jennifer</DIV><DIV>p.s. We are working on the direct GrADS interface to grib2. No promises regarding a time frame, but we hope to have an alpha release sometime this fall for early adopters to try... </DIV><DIV><BR><DIV><DIV>On Jul 5, 2007, at 9:44 PM, Michael Purves wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><PRE>We are making extensive use of GRIB2 meteorological data. I use degrib -c Msg# -Flt -GrADS to convert the GRIB2 data for a given field into a binary float file and a control file. This process works well with all fields, except UGRD and VGRD. In the GRIB2 index files, these fields have a decimal value for the Message Number.<BR><BR>21:525022:d=2007070200:RH Relative humidity [%]:200 mb:6 hour fcst<BR>22.1:546161:d=2007070200:UGRD u wind [m/s]:1000 mb:6 hour fcst<BR>22.2:546161:d=2007070200:VGRD v wind [m/s]:1000 mb:6 hour fcst<BR><BR>If I input the decimal number into degrib, the degrib program crashes. If I enter just the integer value, I get reasonable looking values for the UGRD field, but the VGRD field is identical to UGRD.<BR><BR>Can anyone point me in the right direction to get both UGRD and VGRD from these GRIB2 files?<BR><BR>Thank you,<BR><BR>Michael Purves</PRE><DIV> <BR class="khtml-block-placeholder"></DIV><HR size="1">Be smarter than spam. See how smart SpamGuard is at giving junk email the boot with the <A href="http://us.rd.yahoo.com/evt=40705/*http://mrd.mail.yahoo.com/try_beta?.intl=ca"><B>All-new Yahoo! Mail </B></A></BLOCKQUOTE></DIV><BR><DIV> <SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><DIV>--</DIV><DIV>Jennifer M. Adams</DIV><DIV>IGES/COLA</DIV><DIV>4041 Powder Mill Road, Suite 302</DIV><DIV>Calverton, MD 20705</DIV><DIV><A href="mailto:jma@cola.iges.org">jma@cola.iges.org</A></DIV><DIV><BR class="khtml-block-placeholder"></DIV><BR class="Apple-interchange-newline"></SPAN></SPAN></SPAN> </DIV><BR></DIV></BODY></HTML>