<div dir="ltr"><div>Dear WRF users,</div><div>I have been running WRF model for past 4weeks continuously.</div><div>Now when I do the run, I get big values for the cfl errors. Even when I reduce timestep to as low as 3*dx, I still get the cfl error with big values . This happens immediately the first time integration. Previously the run were fine and was able to do 6years successfully using ERA -interim. </div><div><br></div><div><span lang=""><span lang=""><p>d01 1988-02-01_00:30:00 MAX AT i,j,k: 4 2 40 vert_cfl,w,d(eta)= 7.145714 -25.96785 9.4717517E-03</p><p>
d01 1988-02-01_00:30:00 377 points exceeded cfl=2 in domain d01 at time 1988-02-01_00:30:00 hours</p><p>
d01 1988-02-01_00:30:00 MAX AT i,j,k: 5 2 41 vert_cfl,w,d(eta)= 10.26220 -16.27522 8.7547116E-03</p><p>
Timing for main: time 1988-02-01_00:33:20 on domain 1: 0.67898 elapsed seconds</p><p>
d01 1988-02-01_00:33:20 528 points exceeded cfl=2 in domain d01 at time 1988-02-01_00:33:20 hours</p><p>
d01 1988-02-01_00:33:20 MAX AT i,j,k: 4 2 40 vert_cfl,w,d(eta)= 33.15524 -73.26998 9.4717517E-03</p><p>
d01 1988-02-01_00:33:20 230 points exceeded cfl=2 in domain d01 at time 1988-02-01_00:33:20 hours</p><p>
d01 1988-02-01_00:33:20 MAX AT i,j,k: 10 1 33 vert_cfl,w,d(eta)= 2.872805 -1.684849 1.5666291E-02</p><p>
d01 1988-02-01_00:33:20 105 points exceeded cfl=2 in domain d01 at time 1988-02-01_00:33:20 hours</p><p>
d01 1988-02-01_00:33:20 MAX AT i,j,k: 12 1 33 vert_cfl,w,d(eta)= 2.867926 -2.430345 1.5666291E-02</p><p>
Timing for main: time 1988-02-01_00:36:40 on domain 1: 0.22810 elapsed seconds</p><p>
</p></span><p>Below is my physics and domain settings. Same settings I have used in previous run without any problem. </p></span><p>&physics<br> mp_physics = 6,<br> ra_lw_physics = 4,<br> ra_sw_physics = 4,<br> radt = 30,<br> sf_sfclay_physics = 1,<br> sf_surface_physics = 2,<br> bl_pbl_physics = 1,<br> bldt = 0,<br> cu_physics = 1,<br> cudt = 5,<br> kfeta_trigger = 2,<br> cu_rad_feedback = .true.,<br> isfflx = 1,<br> sst_update = 1,<br> tmn_update = 1,<br> sst_skin = 1,<br> bucket_mm = 100.0,<br> bucket_J = 1.e9,<br> ifsnow = 1,<br> icloud = 1,<br> surface_input_source = 1,<br> num_soil_layers = 4,<br> sf_urban_physics = 0,</p><p><br></p></div><div><br></div><div>&domains<br> time_step = 180,<br> time_step_fract_num = 0,<br> time_step_fract_den = 1,<br> max_dom = 1,<br> e_we = 250,<br> e_sn = 150,<br> e_vert = 51,<br> p_top_requested = 5000,<br> num_metgrid_levels = 38,<br> num_metgrid_soil_levels = 4,<br> dx = 36000, 12000, 3333.33,<br> dy = 36000, 12000, 3333.33,<br> grid_id = 1,<br> parent_id = 1,<br> i_parent_start = 1,<br> j_parent_start = 1,<br> parent_grid_ratio = 1,<br> parent_time_step_ratio = 1,<br> feedback = 1,<br> smooth_option = 0,<br>!sfcp_to_sfcp =.true.,<br>!use_surface = .true.,</div><div><br></div><div><br></div><div><br></div><div>Could the problem related to running model for 4weeks without stoping model to relax.?</div><div>I really don't know where problem is.<div>I got some online info from WRF FAQ Q8 here but didn't understand or got confused</div></div><div><a href="http://www2.mmm.ucar.edu/wrf/users/FAQ_files/FAQ_wrf_physics.html">http://www2.mmm.ucar.edu/wrf/users/FAQ_files/FAQ_wrf_physics.html</a></div><div><br></div></div>