real.exe FATAL: reference pressure not monotonically decreasing (unphysical >10km topography spike)

[Madhusai]

Hello WRF Community,

I am setting up a high-resolution (dx=3km) single-domain simulation using WRFV4.7.1 over Punjab, which covers parts of the Western Himalayan region. I am encountering the classic real.exe fatal error regarding monotonically decreasing reference pressure while I am using the ECMWF IFS operational data.

However, notice the extreme topography value in the error log below—it is generating a spike of 10,449.6875 m, which is a physical impossibility. Here is my error

p_top = 1000. Pa, dzbot = 50.0 m, dzstretch_s/u = 1.30 1.10
----- ERROR: The reference pressure is not monotonically decreasing
This tends to be caused by very high topography
(i,j) = 239 76 , topography = 10449.6875 m
k = 12 , reference pressure = 22399.3789 Pa
k = 13 , reference pressure = 22417.9219 Pa
-------------- FATAL CALLED ---------------
FATAL CALLED FROM FILE: <stdin> LINE: 1249
In the dynamics namelist record, reduce etac from 9.99999978E-03
-------------------------------------------
I have significantly reduced etac (down to 0.01), adjusted p_top, and increased the e_vert levels. No matter what values I choose, the error remains the same.
Any suggestions would be greatly appreciated! I have attached my namelist.input, namelist.wps, and rsl.error.0000 files for reference.

Thank you!

 

[Ming Chen]

In your namelist.input, I found that num_metgrid_levels = 15, which implies that the vertical resolution of the IFS data is way too coarse for the 3km WRF case. Can you try other input data such as GFS to see whether this case works?

Please stay with etac = 0.01.