<div dir="ltr"><div>Dear all,</div><div><br></div><div>
<div class="gmail-wiki">
<p>The second commit of fixing the excessive cooling at cloud top is made into NEMSfv3gfs and FV3 repositories.</p>
        <p>Task <a class="gmail-issue gmail-tracker-28 gmail-status-1 gmail-priority-6 gmail-priority-low2" title="Task: Modification of convection schemes to reduce too much cooling at the cloud top (New)" href="https://vlab.ncep.noaa.gov/redmine/issues/51114">#51114</a>: Modification of convection schemes to reduce too much cooling at the cloud top</p>
        <p>Occasional model crashes have occurred when stochastic physics is
turned on in FV3GFS runs. It was found that in those cases there were
too much convective cooling and heating tendencies near the cumulus top
which are amplified by stochastic physics. To reduce too much convective
cooling at the cloud top, the convection schemes have been modified for
the rain conversion rate, entrainment and detrainment rates,
overshooting layers, and maximum allowable cloud base mass flux. SCM and
3D FV3GFS tests indicate that the modified schemes largely reduce the
too much convective cooling and heating near the cloud top. And there is
no indication of model crash with the modified schemes. FV3GFS
medium-range forecast experiments show that the modified convection
schemes slightly improves forecast skill for 500 hPa height anomaly
correlation while it has a neutral impact on CONUS precipitation
forecast skill</p>
        <p>The code changes alter model results. New baseline was created on
support platforms, regression test passed on wcoss cray, phase1/2, theia
and jet.</p>
        <p>A new tag nemsfv3gfs_beta_v1.0.4 was created after the commit.</p>
</div>
</div><div>Thanks.</div><div><br></div><div>Jun<br></div></div>