[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[IDV #ZRG-103304]: Converting between knots and m/s with flow vectors



> Hi Yuan,
> The barbs indicate winds twice stronger than the data shows.
> If you look at the location of the cross, it reads 21.7 and 9.6 knots. This 
> translates well to the contours in the background (12.2 m/sec).
> 
> But, the barb shows 45 knots, as if IDV calculated the speed in knots (~23.7) 
> and converted again to knots, giving ~46.
> 
> I am using IDV2.9 on WinXP.
> 
> Thanks,
> 
> Ilan

Hi Ilan,
   I think you are right, the u component is no larger than 26.4 knot, and v is 
no larger than 15.2, the IDV should not display anything larger 30 in the wind 
barb. I will check to see what is wrong.



Yuan
> 
> 
> 
> 9.
> 
> -----Original Message-----
> From: Unidata IDV Support [mailto:address@hidden
> Sent: August 16, 2010 2:02 PM
> To: Sills,David [Ontario]
> Cc: Levy,Ilan [Ontario]; Sills,David [Ontario]; address@hidden
> Subject: [IDV #ZRG-103304]: Converting between knots and m/s with flow vectors
> 
> > Hello Julien,
> > Attached are two small sample files.
> >
> > Ilan Levy
> >
> 
> Hi Ilan,
> I don't know which version of the IDV you are running, I am running the 
> IDV2.9 on your data, the result looks correct to me, the highest wind is 
> about 50 knot in my display, and compared to the u and v data, it is right. 
> see the attached image.
> 
> 
> Yuan
> > -----Original Message-----
> > From: Sills,David [Ontario]
> > Sent: August 13, 2010 4:50 PM
> > To: Levy,Ilan [Ontario]
> > Subject: FW: [IDV #ZRG-103304]: Converting between knots and m/s with
> > flow vectors
> >
> > Hi Ilan,
> >
> > The data files are far too large to send to him. Would it be possible to 
> > generate a file that had just one time and one level?
> >
> > I'm on vacation starting tomorrow, so if you could send along to him I'd 
> > appreciate it.
> >
> > Thanks,
> >
> > Dave
> > ______________________________________
> > David Sills, Ph.D.
> > Severe Weather Scientist | Scientifique du temps rigoureux Cloud
> > Physics and Severe Weather Research Section | Section de la recherchÃ
> > sur la physique des nuages et du temps violent National Laboratory for
> > Nowcasting and Remote Sensing Meteorology | Laboratoire national de
> > prÃvision immÃdiate et de mÃtÃorologie par tÃlÃdÃtection Environment
> > Canada | Environnement Canada
> > 4905 Dufferin Street | 4905, rue Dufferin Toronto (Ontario) M3H 5T4
> > address@hidden
> > 905-833-3905 x235 Telephone | TÃlÃphone
> > 905-833-0398 Facsimile | TÃlÃcopieur
> > Government of Canada | Gouvernement du Canada Website | Site web
> >
> > -----Original Message-----
> > From: Unidata IDV Support [mailto:address@hidden
> > Sent: Friday, August 13, 2010 4:47 PM
> > To: Sills,David [Ontario]
> > Cc: address@hidden
> > Subject: [IDV #ZRG-103304]: Converting between knots and m/s with flow
> > vectors
> >
> > Hi, David
> >
> > Would it be possible to send (attach) one of the data files in question?
> >
> > Thanks,
> >
> > -Julien
> >
> > > Hello,
> > >
> > > I have data files with wind in knots. When I plot them as wind
> > > barbs, it appears as though IDV treats the data as m/s, and then
> > > does a conversion to knots. This results in the winds being much
> > > higher in the plot than they should be.
> > >
> > > What is the best way to get around this problem?
> > >
> > > Many thanks,
> > >
> > > Dave
> > > ______________________________________
> > > David Sills, Ph.D.
> > > Severe Weather Scientist | Scientifique du temps rigoureux Cloud
> > > Physics and Severe Weather Research Section | Section de la
> > > recherchà sur la physique des nuages et du temps violent National
> > > Laboratory for Nowcasting and Remote Sensing Meteorology |
> > > Laboratoire national de prÃvision immÃdiate et de mÃtÃorologie par
> > > tÃlÃdÃtection Environment Canada | Environnement Canada
> > > 4905 Dufferin Street | 4905, rue Dufferin Toronto (Ontario) M3H 5T4
> > > address@hidden
> > > 905-833-3905 x235 Telephone | TÃlÃphone
> > > 905-833-0398 Facsimile | TÃlÃcopieur Government of Canada |
> > > Gouvernement du Canada Website
> > > <http://www.ec.gc.ca/scitech/default.asp?lang=En&n=F97AE834-1&xsl=sc
> > > it echprofile,form&formid=A9E422E3-F382-4017-A64E-E58E6BC14CC9>  |
> > > Site web
> > > <http://www.ec.gc.ca/scitech/default.asp?lang=Fr&n=F97AE834-1&xsl=sc
> > > it echprofile,form&formid=A9E422E3-F382-4017-A64E-E58E6BC14CC9>
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: ZRG-103304
> > Department: Support IDV
> > Priority: Normal
> > Status: Open
> >
> >
> >
> 
> 
> Ticket Details
> ===================
> Ticket ID: ZRG-103304
> Department: Support IDV
> Priority: Normal
> Status: Closed
> 
> 
> 
> 


Ticket Details
===================
Ticket ID: ZRG-103304
Department: Support IDV
Priority: Normal
Status: Open


NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.