Temperature 2m ​​above the ground too cold

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Gippox
Posts: 65
Joined: Sat Mar 02, 2013 1:16 am

Re: Temperature 2m ​​above the ground too cold

Post by Gippox » Fri Jan 03, 2014 6:31 pm

meteoadriatic wrote:
Gippox wrote:SNOW and SNOWH are not present as output parameters
Where? In gribs or in wrfout fields? in wrfout fields they should be if I recall correctly. In gribs snodsfc is SNOWH field.
In grib2 fields, after conversion with grib2ctl.pl i don't see SNOW or SNOWH, only snodsfc,
For wrfinput_d01 or wrfinput_d01 files (netcdf format) i think i should use ncl, but for now i don't have done yet.

meteoadriatic
Posts: 1602
Joined: Wed Aug 19, 2009 10:05 am

Re: Temperature 2m ​​above the ground too cold

Post by meteoadriatic » Fri Jan 03, 2014 6:36 pm

Gippox wrote:In grib2 fields, after conversion with grib2ctl.pl i don't see SNOW or SNOWH, only snodsfc,
For wrfinput_d01 or wrfinput_d01 files (netcdf format) i think i should use ncl, but for now i don't have done yet.
Yes SNOWH is converted directly into snodsfc variable. SNOW, I have no idea what UPP does with it.

You can easy look into wrfinput*, wrfout* and met* files with ncview utility. You can't save plots with it though.

dominic
Posts: 336
Joined: Thu Jun 14, 2012 7:19 am

Re: Temperature 2m ​​above the ground too cold

Post by dominic » Fri Jan 03, 2014 11:12 pm

meteoadriatic wrote:
dominic wrote:Superb Ivan O_O how did you do this plot. I would not know how to get started with grads: D
would be nice to understand how it is made ​​up of your script
OK here it is.

First, enable snow and rain mixing ratios on lowest model level:

Code: Select all

 (SNOW ON MDL SFCS    ) SCAL=( 6.0)
 L=(10000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000)
 (RAIN ON MDL SFCS    ) SCAL=( 6.0)
 L=(10000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000)
Add those lines in your *cntrl.parm in static directory. If they are there make them look like that (with "1" on first digit). Then after next postprocess you will have variables RWMRhlev1 for rain mixing ratio and SNMRhlev1 for snow mixing ratio on lowest model level near ground, that is where you probably want to get data. If you want on higher levels, change also higher "zeros" to "ones".

Now with those two variables you will know where there is much more snow than rain (it is snow), where it is much more rain than snow (it is rain), or where it is approx. equal amount (it is mixed precipitation - sleet).

In grads script:

Code: Select all

'set gxout shade2b'
'set clevs 0 0.2 10'
'set ccols 2 2 3 11'
'define snowrainratio=(SNMRhlev1+0.0000001)/(RWMRhlev1+0.0000001)+0.01'
'define precthreshold=((SNMRhlev1+RWMRhlev1)*1000000)-1'
'd maskout(snowrainratio,precthreshold)'
Don't ask me why those strange numbers... it is not easy to explain in details (it has to do with very small and very large (infinity) numbers when you divide with zero or like that... to be computable at all just do like I did :) )

That's all, everything else in your script do as always you do.

Ivan perfect!, It works fine :)

You can make it similar to the Lamma? ie inserting Freeze Rain (freezing rain)?

Ice Pellets should already be in your script :)

Watch


PS: also the convective precipitation (storms) would not be bad, indeed: D

http://postimg.org/image/g4q3ml2yn/191e4f95/

meteoadriatic
Posts: 1602
Joined: Wed Aug 19, 2009 10:05 am

Re: Temperature 2m ​​above the ground too cold

Post by meteoadriatic » Sat Jan 04, 2014 9:34 am

dominic wrote: Ivan perfect!, It works fine :)

You can make it similar to the Lamma? ie inserting Freeze Rain (freezing rain)?

Ice Pellets should already be in your script :)

Watch


PS: also the convective precipitation (storms) would not be bad, indeed: D

http://postimg.org/image/g4q3ml2yn/191e4f95/
For freezing rain another approach is needed. I planned to do so but didn't yet thought how.

dominic
Posts: 336
Joined: Thu Jun 14, 2012 7:19 am

Re: Temperature 2m ​​above the ground too cold

Post by dominic » Sat Jan 04, 2014 1:32 pm

meteoadriatic wrote:
dominic wrote: Ivan perfect!, It works fine :)

You can make it similar to the Lamma? ie inserting Freeze Rain (freezing rain)?

Ice Pellets should already be in your script :)

Watch


PS: also the convective precipitation (storms) would not be bad, indeed: D

http://postimg.org/image/g4q3ml2yn/191e4f95/
For freezing rain another approach is needed. I planned to do so but didn't yet thought how.


hello ivan, you can make the sum of 24 hours? to get a picture of the daily precipitation type? formula which can be applied to sum pr?

meteoadriatic
Posts: 1602
Joined: Wed Aug 19, 2009 10:05 am

Re: Temperature 2m ​​above the ground too cold

Post by meteoadriatic » Sat Jan 04, 2014 1:44 pm

dominic wrote:hello ivan, you can make the sum of 24 hours? to get a picture of the daily precipitation type? formula which can be applied to sum pr?
That's the easiest possible thing:

'define sum = apcpsfc - apcpsfc(t-24)'

If your precipitation variable is something else, replace apcpsfc with it. And if your output time step isn't 1 hour, adjust that t-24 to how much time steps you have in one day.

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