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>From: "Paul L. Sirvatka" <address@hidden> >Organization: College of DuPage >Keywords: 200102252359.f1PNxUL00972 McIDAS-X RAOBCON PTCON speed contours Paul, >On this map, why is there a zero speed contour? > >http://weather.cod.edu/mcimages/uppergifs/h7spd.gif > >here is actually a NEGATIVE SPEED!!!! > >http://weather.cod.edu/mcimages/uppergifs/h8spd.gif It appears that you have discovered a black hole right in the Texas panhandle! But seriously, I sent your observation to SSEC to alert them that something must be amiss in the objective analysis routine. I tried to reproduce your display from 12Z upper air data on 2001/02/25 while pointing at adde.ucar.edu, but I was unable to get a plot that had zero or negative contours. This might mean that the problem is in the decoding of the data. Which ADDE server were you pointing at when you created your displays? >both were done with RAOBCON RAOBCON runs PTCON, so PTCON is the one producing the bad objective analysis. After the objective analysis, GRDDISP is the one that plots the contours. The culprit has to be the objective analysis routine in PTCON. >Hmmmm? If this had been over AREA 51 (Nevada), I _might_ have understood :-) Tom >From address@hidden Mon Feb 26 07:54:32 2001 >To: address@hidden >Subject: 20010225: RAOBCON producing 0 and negative contours for wind speed Hi, One of my sites just sent me this note about RAOBCON producing contours for zero and negative wind speeds. I guess the question of the day is how a negative wind speed contour can ever be generated? Tom ------- Forwarded Message On this map, why is there a zero speed contour? http://weather.cod.edu/mcimages/uppergifs/h7spd.gif here is actually a NEGATIVE SPEED!!!! http://weather.cod.edu/mcimages/uppergifs/h8spd.gif both were done with RAOBCON Hmmmm? Paul -- ****************************************************************************** * Paul L. Sirvatka | Office: (630) 942-2118; Lab: (630) 942-2590 * * Professor of Meteorology | COD Weather Lab: (630)-858-0032 * * College of DuPage | Address: 425 22nd St. Glen Ellyn, IL 60137 * ****************************************************************************** ------- End of Forwarded Message