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[IDV #RWW-752224]: NARR forecast soundigns



Hi Mike,

For the sounding plot, yes, I believe this is possible, but since you did not
point us to a specific data set, I just picked one of the NARR-A datasets
(http://www.ncdc.noaa.gov/data-access/model-data/model-datasets/north-american-regional-reanalysis-narr)
and I accessed it from a THREDDS server rather than downloading it. For example,

http://nomads.ncdc.noaa.gov/thredds/narr/narr-a.xml

The issue here is that you have to work with the specific humidity (rather than
relative humidity, dew point, mixing ratio, etc.). But no problem, IDV to the
rescue. You have to set up one or more IDV derived formulas, coupled with a Java
method DerivedGridFactory.createRelativeHumidity
(https://www.unidata.ucar.edu/software/idv/docs/javadoc/ucar/unidata/data/grid/DerivedGridFactory.html#createRelativeHumidity-visad.FieldImpl-visad.FieldImpl-boolean-)
accessed via a Jython function. This is very tricky business even for me, so I
simply did it for you in the attached jar plugin file. 

You need to install the plugin via the Tools --> Plugin Manager. Go to File ->
Install Plugin From File.

The plugin has three files:

- aliases.xml which contains a Specific_humidity to mixing ratio alias. (This 
makes sense when you use the Java method described earlier with the 
isSpecificHumidity boolean flag)
- derived.xml which contains three derivation formulas for the relative 
humidity, dew point, and sounding.
- default.py which contains a Jython function that invokes the Java method above

You can now plot the sounding along with dew point and relative humidity 
derivations.

As for the surface elevation issue, I am not sure about this one. If you can
find a field that will mask out the temperature, specific humidity, and winds
below the surface then that might be an avenue of pursuit.

Best

Unidata IDV Support

> http://www.ncdc.noaa.gov/has/has.dsselect
> 
> 
> It's just the files under models, North American Regional Reanalysis.  They 
> don't end in grb2 like the rap or ruc files once untarred.  They have awips 
> in their file name, but not sure how exactly they are different when untarred 
> and what they are just that they don't say .grb2 .  They open like the others 
> for the most part but at least the sounding option doesn't seem to be there.
> 
> 
> Otherwise as far as the height thing was concerned that was just the 
> bottom/ground of the sounding starting at I guess sea level on the graph and 
> not adjusting like if you were plotting from the high plains somewhere.  
> Doesn't affect the hodo as it just uses the same flow "below ground" as the 
> surface flow but looks odd when displaying the sounding.  Maybe there's some 
> way in a setting to have it do so but maybe not.  I'm guessing there's some 
> reason there's no sounding route in those NARR files.  I've looked and looked 
> through all the drop downs a couple times and don't think I've missed it that 
> way.
> 
> 
> Thanks,
> 
> Mike
> 
> ________________________________
> From: Unidata IDV Support <address@hidden>
> Sent: Thursday, September 29, 2016 7:46:20 AM
> To: address@hidden
> Cc: address@hidden
> Subject: [IDV #RWW-752224]: NARR forecast soundigns
> 
> Mike,
> 
> Could you point us to a sample of the data you are referring to?
> 
> Best,
> 
> Unidata IDV Support
> 
> 
> > Just 2 quick questions.  I've located where to pull forecast soundings
> > from archived ruc and rap models(3d, temp, derived, sounding data)...but
> > I've looked everywhere with open NARR files and am now under the
> > assumption it's not possible.  Just thought I'd ask real quick to be sure .
> >
> > Also I see the soundings from the others are plotted without adjusting
> > for elevation at the bottom of the sounding.    Is there any way to
> > change that?  For a visual sake. I'm thinking probably not but figured
> > I'd ask that real quick too.
> >
> > Thanks,
> >
> > Mike
> >
> >
> 
> 
> Ticket Details
> ===================
> Ticket ID: RWW-752224
> Department: Support IDV
> Priority: Normal
> Status: Closed
> ===================
> 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.
> 
> 
> 
> 


Ticket Details
===================
Ticket ID: RWW-752224
Department: Support IDV
Priority: Normal
Status: Closed
===================
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.

Attachment: narr.jar
Description: application/java-archive

Attachment: sounding.png
Description: PNG image


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.