Scheduled Downtime
On Friday 21 April 2023 @ 5pm MT, this website will be down for maintenance and expected to return online the morning of 24 April 2023 at the latest

Missing Specific AFWA Diagnostics (WRF 4.1.3, 4.2.2)

This post was from a previous version of the WRF&MPAS-A Support Forum. New replies have been disabled and if you have follow up questions related to this post, then please start a new thread from the forum home page.


New member

I have been trying to run a high-resolution convective case (~3km horizontal domain) initialized using GEFS reforecast data (I construct the intermediate files using the minimum WRF required variables per the documentation), and while the model itself does complete and I do generate convection in expected locations, I am missing a few AFWA diagnostics that I need for my study (Namely, AFWA_HAIL and AFWA_TORNADO).

The documentation for these diagnostics is lacking as it pertains to requirements to use them, I tried using Thompson microphysics (mp_physics = 8), but apparently, this package does not support AFWA as it does not compute certain Q indices. I then tried using WSM6 (mp_physics = 16), which does compute these indices, but those two variables are still not computed. Other AFWA diagnostics pertinent to convection (IE: AFWA_CAPE, AFWA_CIN, etc) are present in the output.

Any pointers would be appreciated. I have attached my latest namelist, IO_VARS, and ncdump from the first wrfout file to the post here. I can also provide additional information (IE: Input Data, Etc) as necessary.



  • IO_VARS.txt
    1.4 KB · Views: 18
  • namelist.input
    6.3 KB · Views: 29
  • ncdump.txt
    26.5 KB · Views: 20
Just a quick update from some more digging / research.

Looking at the AFWA diagnostics code:
CALL wrf_debug ( DEBUG_LEVEL, 'Option severe_wx_diagnostics requires: QV, QR, QC, QI, QS, QG, QNG' )

So this is tied specifically to the selection of microphysics scheme (Makes sense for Hail). The big gotcha, is that a large number of schemes does not compute QNG, in fact, only five schemes I see in the registry do so:

package   milbrandt2mom   mp_physics==9                -             moist:qv,qc,qr,qi,qs,qg,qh;scalar:qnc,qnr,qni,qns,qng,qnh
package   morr_two_moment mp_physics==10               -             moist:qv,qc,qr,qi,qs,qg;scalar:qni,qns,qnr,qng;state:rqrcuten,rqscuten,rqicuten
#package   milbrandt3mom  mp_physics==12               -             moist:qv,qc,qr,qi,qs,qg,qh;scalar:qnc,qnr,qni,qns,qng,qnh,qzr,qzi,qzs,qzg,qzh
package   nssl_2mom       mp_physics==17               -             moist:qv,qc,qr,qi,qs,qg,qh;scalar:qndrop,qnr,qni,qns,qng,qnh,qvolg,qvolh;state:re_cloud,re_ice,re_snow
package   nssl_2momccn    mp_physics==18               -             moist:qv,qc,qr,qi,qs,qg,qh;scalar:qnn,qndrop,qnr,qni,qns,qng,qnh,qvolg,qvolh;state:re_cloud,re_ice,re_snow
package   nssl_2momg      mp_physics==22               -             moist:qv,qc,qr,qi,qs,qg;scalar:qndrop,qnr,qni,qns,qng,qvolg;state:re_cloud,re_ice,re_snow

Using one of these schemes produces output as expected from AFWA.

I guess the thing I'm curious about now, is what specifically do we need QNG for? There are quite a few number of MP schemes out there that compute all of these indices except QNG, some even compute other 'QN' indices, but not QNG.
Many thanks for the kind information you provide regarding the AFWA diagnostic.
For your question of QNG, please take a look at this paper:
Probably it can provide some helpful information to answer your question.