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[IDV #RVK-621478]: McIDAS-V inquiry #1048 updated



Dear Becky,

This thread is getting rather long, so just for clarification, as far as I can 
tell, wind barbs are plotted consistently between the plan view and the time 
series plots. Let me know if you see otherwise.

On the issue of low-speed winds, wind barbs have been plotted in the IDV plan 
view in this fashion for ~10 years. Therefore, I am reluctant to make any 
changes without very good reason. I believe the IDV wind barbs are consistent 
with other meteorological visualization packages.

Best Regards,
Unidata IDV Support

> 
> 
> 
> 
> 
> 
> Hello again! 
> 
> Here's one more that I sent a few weeks ago, but haven't seen a
> response.  Julien did some initial work to get the layer controls
> and main display plotting the same, but our testers have found that
> the WMO standard is to plot winds less than 3 kt as a barb with no
> flags rather than a circle.   Have you had a chance to look into it
> again?
> 
> Thanks!
> Becky
> 
> On 9/7/2011 2:06 PM, McIDAS Help Desk wrote:
> 
> 
> 
> Can you update us on the status of this ticket?   It's more of a
> standard for winds less than 3kts to be plotted as a barb with no
> flags, but now it's plotted as a circle.  Can you switch it so
> that both the layer controls and main display plot these as a barb
> with no flags?
> 
> 
> 
> 
> 
> 
> -------- Original Message --------
> 
> 
> 
> Subject:
> 
> 
> Re: [IDV #RVK-621478]: McIDAS-V inquiry #1048 updated
> 
> 
> Date:
> 
> Fri, 05 Aug 2011 09:14:36 -0500
> 
> 
> From:
> 
> Bob Carp <address@hidden>
> 
> 
> To:
> address@hidden
> 
> 
> CC:
> address@hidden
> 
> 
> 
> 
> 
> Hi -
> 
> Sorry for the delayed response. I was looking into this issue myself,
> and I have found a few reliable sources that state that wind barbs for
> winds of less than 3kts are plotted as a barb with no flags. Below are
> some of the places I saw that reference this:
> 
> Training course from the United States Navy (page 165 in the chart)
> http://www.hnsa.org/doc/pdf/aerographer1.pdf
> 
> Applied Atmospheric Dynamics (Text book, pages 7 - 8)
> http://books.google.com/books?id=7IsmskcU3msC&pg=PA7&lpg=PA7&dq=wind+barb+1kt+wind&source=bl&ots=5sazNCEaT-&sig=V58M9VOKCKeDrTY8liAyTP89Dco&hl=en&ei=4hUwTvr0MYiwsAKF4KBZ&sa=X&oi=book_result&ct=result&resnum=4&ved=0CC0Q6AEwAw#v=onepage&q=wind%20barb%201kt%20wind&f=false
> 
> University of Washington
> http://www.atmos.washington.edu/mm5rt/descript/definitions/windbarbs.html
> 
> MAV MOS wind barbs from the NWS shows barbs without any flags on them
> http://www.nws.noaa.gov/mdl/forecast/graphics/MAV/MAV.BRBK_000.html
> 
> Thanks
> Bob
> 
> On 7/28/2011 2:15 PM, Unidata IDV Support wrote:
> > Bob,
> >
> > The wind barbs are now consistent between plots and views. Please get 
> the nightly build tomorrow to confirm.
> >
> > Best Regards,
> >
> > -Unidata IDV Support
> >
> >> Bob,
> >>
> >> I could be wrong, but here is my analysis of the situation which is 
> backwards from yours.
> >>
> >> First off, people appear to deal with wind barbs in knots rather 
> than meters per second.
> >>
> >> Second, my understanding is that wind speeds from 0 to 5 knots are 
> calm represented by a circle. After that, (i.e.>= 5 knots), we start to 
> see lines with barbs attached. The map view wind barbs, rendered with VisAD, 
> seem to do this correctly. Strictly speaking, as far as I can tell, there is 
> no wind barb line without a barb.
> >>
> >> In conclusion, I think the Map View of wind barbs are correct, but 
> the Dashboard Plot does not deal with calm wind speeds correctly. I would 
> recommend fixing the Dashboard plots of wind barbs for low wind speeds.
> >>
> >> Best Regards,
> >>
> >> -Unidata IDV Support
> >>
> >>> While in most cases this problem appears to be fixed, there is 
> still an issue when a station is reading 1 m/s wind. When this is the case, 
> the plot in the Main Display Window shows an open circle, while the plot in 
> the Layer Controls (Displays) tab displays a barb without any flags. However, 
> the barb in the Layer Controls (Displays) tab does point the proper direction 
> with respect to the wind direction reported.
> >>>
> >>> This is a case where the barb is plotted correctly in the Layer 
> Controls (Displays) tab and not in the Main Display Window. This is the only 
> circumstance where I could find any inconsistency between the two displays.
> >>>
> >>> ----==== Inquiry ====----
> >>> 1048
> >>>
> >>> ----==== Summary ====----
> >>> Point data wind barbs differ between map display and plot in 
> layer controls
> >>>
> >>>
> >>> 
> ################################################################################
> >>>
> >>> http://dcdbs.ssec.wisc.edu/inquiry-v/index.php?inquiry=1048
> >>>
> >>>
> >
> > Ticket Details
> > ===================
> > Ticket ID: RVK-621478
> > Department: Support IDV
> > Priority: Normal
> > Status: Closed
> >
> 
> 
> 
> 
> 
> 
> 
> 


Ticket Details
===================
Ticket ID: RVK-621478
Department: Support IDV
Priority: Critical
Status: Closed


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