[IDV #TGD-838573]: Relative humidity from wrfouts

Hi Youssef,

What was your WRF output post-processing scheme?

At any rate, as you say,  you will have to alias TEMP and MIXR.

For the 2D grid variables, this is probably

T2 for TEMP
Q2 for MIXR

For the 3D grid variables

?????? for TEMP
QVAPOR for MIXR

Once the aliases are in place, right-click on the WRF data source in the Data
sources panel of the Field Selector and "Reload Data". Then the relative
humidity derived field will appear, under the "Derived" node in the field
selector tree.

For the 2D grid variables, unfortunately, the derived relative humidity
calculation will not work because of a problem earlier described here:

http://www.unidata.ucar.edu/support/help/MailArchives/idv/msg06687.html

which is too bad because relative humidity is only really useful at the
surface. So you have to rely on the 3D derivation, but I do not see the
temperature field for the 3D data. Is the 3D temperature available perhaps
through post-processing?

By the way, at least in this case, you cannot mix and match 2D (e.g., T2) and 3D
(e.g., QVAPOR) fields when using IDV formulas. Sorry to have misled you about
this in the earlier response.

Best,

Unidata IDV Support


> Hello,
> 
> A sample wrfout file is now uploaded to the server. Again, all I need is to 
> derive RH using the IDV formula: 
> DerivedGridFactory.createRelativeHumidity(D1, D2). Thank you for your support.
> 
> Best,
> Youssef
> 
> 
> -----Original Message-----
> From: Unidata IDV Support [mailto:address@hidden]
> Sent: Monday, October 03, 2016 8:05 AM
> Cc: address@hidden
> Subject: [IDV #TGD-838573]: Relative humidity from wrfouts
> 
> Hi Youssef,
> 
> At this point, I need to see a sample data file.
> 
> Please upload a sample of your WRF output to
> 
> http://motherlode.ucar.edu/repository/alias/idvupload
> 
> Best,
> 
> Unidata IDV Support
> 
> > Package Version: 5.3 build date:2016-05-23 19:17 UTC Operating System:
> > Windows 7
> > Hardware: Java: home: C:\Program Files\IDV_5.3\jre version: 1.8.0_45
> > j3d:1.6.0-pre9-daily-experimental daily Description of problem:
> > Creating display: Omni Control
> > java.lang.ClassCastException: java.lang.ClassCastException:
> > visad.Linear2DSet cannot be cast to visad.Gridded3DSet
> > visad.Linear2DSet cannot be cast to visad.Gridded3DSet
> >
> > Hello,
> > I am trying to derive Relative Humidity from my wrfout files. I have
> > tried setting aliases TEMP --> T2 and MIXR --> QVAPOR among many other
> > things and still have not been able to display RH. Please advise.
> > Thank you
> >
> > ******************
> > Stack trace:
> > java.lang.ClassCastException: visad.Linear2DSet cannot be cast to
> > visad.Gridded3DSet at
> > ucar.unidata.data.grid.DerivedGridFactory.createPressureGridFromDomain
> > (DerivedGridFactory.java:3422) at
> > ucar.unidata.data.grid.DerivedGridFactory.createRelativeHumidity(Deriv
> > edGridFactory.java:2541) at
> > ucar.unidata.data.grid.DerivedGridFactory.createRelativeHumidity(Deriv
> > edGridFactory.java:2501) at
> > sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
> > sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at
> > sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at
> > java.lang.reflect.Method.invoke(Unknown Source) at
> > org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:
> > 186) at
> > org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:
> > 204) at org.python.core.PyObject.__call__(PyObject.java:478)
> > at org.python.core.PyObject.__call__(PyObject.java:482)
> > at org.python.pycode._pyx74.f$0(<string>:1)
> > at org.python.pycode._pyx74.call_function(<string>)
> > at org.python.core.PyTableCode.call(PyTableCode.java:167)
> > at org.python.core.PyCode.call(PyCode.java:18)
> > at org.python.core.Py.runCode(Py.java:1386)
> > at org.python.core.__builtin__.eval(__builtin__.java:497)
> > at org.python.core.__builtin__.eval(__builtin__.java:501)
> > at org.python.util.PythonInterpreter.eval(PythonInterpreter.java:251)
> > at
> > ucar.unidata.data.DerivedDataChoice.getData(DerivedDataChoice.java:795
> > ) at ucar.unidata.data.DataChoice.getData(DataChoice.java:628)
> > at ucar.unidata.data.DataInstance.getData(DataInstance.java:243)
> > at ucar.unidata.data.DataInstance.getData(DataInstance.java:207)
> > at ucar.unidata.data.DataInstance.dataOk(DataInstance.java:295)
> > at
> > ucar.unidata.idv.control.OmniControl.createDataInstances(OmniControl.j
> > ava:348) at
> > ucar.unidata.idv.control.OmniControl.setData(OmniControl.java:281)
> > at ucar.unidata.idv.control.OmniControl.init(OmniControl.java:165)
> > at
> > ucar.unidata.idv.control.DisplayControlImpl.init(DisplayControlImpl.ja
> > va:1124) at
> > ucar.unidata.idv.ControlDescriptor.initControl(ControlDescriptor.java:
> > 986) at
> > ucar.unidata.idv.ControlDescriptor$1.run(ControlDescriptor.java:911)
> > at ucar.unidata.util.Misc$3.run(Misc.java:1243)
> >
> >
> >
> 
> 
> Ticket Details
> ===================
> Ticket ID: TGD-838573
> 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: TGD-838573
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.