[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 recherché
> > sur la physique des nuages et du temps violent National Laboratory for
> > Nowcasting and Remote Sensing Meteorology | Laboratoire national de
> > prévision immédiate et de météorologie par télédétection Environment
> > Canada | Environnement Canada
> > 4905 Dufferin Street | 4905, rue Dufferin Toronto (Ontario) M3H 5T4
> > address@hidden
> > 905-833-3905 x235 Telephone | Téléphone
> > 905-833-0398 Facsimile | Télécopieur
> > 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
> > > recherché sur la physique des nuages et du temps violent National
> > > Laboratory for Nowcasting and Remote Sensing Meteorology |
> > > Laboratoire national de prévision immédiate et de météorologie par
> > > télédétection Environment Canada | Environnement Canada
> > > 4905 Dufferin Street | 4905, rue Dufferin Toronto (Ontario) M3H 5T4
> > > address@hidden
> > > 905-833-3905 x235 Telephone | Téléphone
> > > 905-833-0398 Facsimile | Télécopieur 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