No rain in output

Topics related to current and future physics in the WRF as well as any problems you may have.

No rain in output

Postby adrian_champion » Thu Sep 13, 2012 5:19 am

Hi all

I'm running WRF over a UK domain at a 12km resolution for 48 hours from ECMWF Operational Analysis data. My model runs successfully however it produces no rain (rainc, rainsh, rainnc) at all for any timestep. The physics options in my namelist.input are:

&physics
mp_physics = 1, 1,
ra_lw_physics = 1, 1,
ra_sw_physics = 1, 1,
radt = 30, 30,
sf_sfclay_physics = 1, 1,
sf_surface_physics = 0, 0,
bl_pbl_physics = 1, 1,
bldt = 0, 0,
cu_physics = 1, 1,
cudt = 5, 5,
isfflx = 1,
ifsnow = 0,
icloud = 1,
surface_input_source = 1,
num_soil_layers = 4,
sf_urban_physics = 0, 0,
/

Is there anything obvious in the above that would prevent rain from being forecast?

Thanks

Adrian
--
Adrian Champion
http://www.reading.ac.uk/~wk903847
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Re: No rain in output

Postby jan » Fri Sep 14, 2012 4:24 am

I can`t see anything obvious. The Kessler scheme you are using, should include rain. Do you see the varaibles rainc, rainnc? Maybe it just did not rain in your 48 hours forecast time? Which would be, of course, quite unusual for the UK ... :)
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Re: No rain in output

Postby adrian_champion » Fri Sep 14, 2012 5:55 am

I do see all the variables (rainc, rainsh, rainnc), and the only "rain" I get is one grid box showing a little bit of rain for one timestep.

Both unusual for the UK and given I'm doing a re-forecast for July 2007 when we experienced widespread floods due to prolonged intense rain...!
--
Adrian Champion
http://www.reading.ac.uk/~wk903847
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Re: No rain in output

Postby jan » Fri Sep 14, 2012 7:34 am

RAINC comes from the cumulus scheme and RAINNC from the microphysics. Both your scheme should calculate rain.
As I can see from your namelist.input, there is no bucket activated and consequently you do not have variables as I_RAINC, or?
What about your boundary conditions and initialization data, do they have some rain? You could check this in the met_em files.
Or is it just a problem of how you visualize or analyse the data? Did you write out the correct time stamp at the end of your simulation? Since the values are accumulated ... Just some ideas.
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Location: Kiel, Germany, GEOMAR

Re: No rain in output

Postby miklosera » Fri Nov 02, 2012 11:29 am

Hi,
I have the same problem as no rain for Europe for a month that is quite unusual as well...
I'm just a beginner with WRF so am I right that I don't have to give input precipitation to the model but it will count it...?
I checked my met_em files and there are no rain files there at all.
Any suggestion??
Thanks
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Re: No rain in output

Postby jan » Fri Nov 02, 2012 2:31 pm

No, your input data does not need to contain rain as a variable. But relative or specific humidity though.
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Re: No rain in output

Postby miklosera » Wed Nov 14, 2012 8:45 am

Coudl you check out this namelist.input?
I still don't have rain....

'&logging
/'
&time_control
run_days = 30,
run_hours = 0,
run_minutes = 0,
run_seconds = 0,
start_year = 2009,
start_month = 11,
start_day = 1,
start_hour = 0,
start_minute = 00,
start_second = 00,
end_year = 2009,
end_month = 12,
end_day = 1,
end_hour = 0,
end_minute = 00,
end_second = 00,
interval_seconds = 21600,
input_from_file = .true.,
history_interval = 180,
frames_per_outfile = 1000,
restart = .false.,
restart_interval = 5000,
io_form_history = 2,
io_form_restart = 2,
io_form_input = 2,
io_form_boundary = 2,
debug_level = 0,
/

&domains
time_step = 300,
time_step_fract_num = 0,
time_step_fract_den = 1,
max_dom = 1,
e_we = 100,
e_sn = 100,
e_vert = 28,
p_top_requested = 5000,
num_metgrid_levels = 27,
num_metgrid_soil_levels = 4,
dx = 50000,
dy = 50000,
grid_id = 1,
parent_id = 1,
i_parent_start = 1,
j_parent_start = 1,
parent_grid_ratio = 1,
parent_time_step_ratio = 1,
feedback = 1,
smooth_option = 0,
/

&physics
mp_physics = 1,
ra_lw_physics = 1,
ra_sw_physics = 1,
radt = 30,
sf_sfclay_physics = 1,
sf_surface_physics = 2,
bl_pbl_physics = 1,
bldt = 0,
cu_physics = 1,
cudt = 5,
isfflx = 1,
ifsnow = 0,
icloud = 1,
surface_input_source = 1,
num_soil_layers = 4,
sf_urban_physics = 0,
maxiens = 1,
maxens = 3,
maxens2 = 3,
maxens3 = 16,
ensdim = 144,
/

&fdda
/

&dynamics
w_damping = 0,
diff_opt = 1,
km_opt = 4,
diff_6th_opt = 0,
diff_6th_factor = 0.12,
base_temp = 290.,
damp_opt = 0,
zdamp = 5000.,
dampcoef = 0.2,
khdif = 0,
kvdif = 0,
non_hydrostatic = .true.,
moist_adv_opt = 1,
scalar_adv_opt = 1,
/

&bdy_control
spec_bdy_width = 5,
spec_zone = 1,
relax_zone = 4,
specified = .true.,
nested = .false.,
/

&grib2
/

&namelist_quilt
nio_tasks_per_group = 0,
nio_groups = 1,
/
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Re: No rain in output

Postby jan » Wed Nov 14, 2012 9:39 am

Your namelist looks ok.
I have no clue what your problem might be! Does the variable RAINNC really has only zero (or missing?) entries everyhwhere and at all times?? Use ncview to check. Do you have clouds (CLDFRA)?
Total precipitation = non-convective + convective precipitation (RAINNC + RAINC).
It happend to me, that the model crashed but continued to run. Check the rsl.error.* messages for
CFL-criterion violations (grep -i "cfl" rsl.error.*).
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Re: No rain in output

Postby miklosera » Fri Nov 16, 2012 7:46 am

I dont have any rsl error.... :S
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Re: No rain in output

Postby jimmyc » Fri Nov 16, 2012 9:27 pm

Have you checked the output from real to make sure all of your humidity data was present?

At the initial time you can also check to make sure qvapor looks good.
The views expressed in this message do not necessarily reflect those of NOAA or the National Weather Service or the University of Oklahoma.
James Correia, Jr
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