diff --git a/configs/sites/tier1/acorn/deployments.yaml b/configs/sites/tier1/acorn/deployments.yaml
index 30912cfb4..98bff7cae 100644
--- a/configs/sites/tier1/acorn/deployments.yaml
+++ b/configs/sites/tier1/acorn/deployments.yaml
@@ -44,6 +44,11 @@ deployments:
     walltime: 03:15:00
     site: wcoss2
 
+  - template: "gsi-ncdiag-1.1.3"
+    compilers: ["oneapi@2024.2.1", "intel@19.1.3.304"]
+    walltime: 00:05:00
+    upstreams: [unified-dev]
+
 batch_config:
   scheduler: pbspro
   account: NCEPLIBS-DEV
diff --git a/configs/templates/gsi-ncdiag-1.1.3/envrepo/packages/gsi-ncdiag/package.py b/configs/templates/gsi-ncdiag-1.1.3/envrepo/packages/gsi-ncdiag/package.py
new file mode 100644
index 000000000..59548e403
--- /dev/null
+++ b/configs/templates/gsi-ncdiag-1.1.3/envrepo/packages/gsi-ncdiag/package.py
@@ -0,0 +1,38 @@
+# Copyright Spack Project Developers. See COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack_repo.builtin.build_systems.cmake import CMakePackage
+
+from spack.package import *
+
+
+class GsiNcdiag(CMakePackage):
+    """GSI NetCDF Diagnostics Library and Utility Tools"""
+
+    homepage = "https://github.com/NOAA-EMC/GSI-ncdiag"
+    url = "https://github.com/NOAA-EMC/GSI-ncdiag/archive/refs/tags/v1.1.1.tar.gz"
+    git = "https://github.com/NOAA-EMC/GSI-ncdiag"
+
+    maintainers("ulmononian")
+
+    version("1.1.3", tag="v1.1.3", commit="7a9a5c2d4795e2badfabd429bc04d921b4b34b0d")
+    version("1.1.2", sha256="085884106be1f8fd94a70292102e9351c0efdf1e619a233831fafcd9ed32cd99")
+    version("1.1.1", sha256="26fc10cf448dd62daa1385e38921d338778416342956c478337e6c6d1b20bf8c")
+    version("1.1.0", sha256="9195801301209d6f93890944d58ffee4e24a4e35502ab27560a8c440ee53df4c")
+    version("1.0.0", sha256="7251d6139c2bc1580db5f7f019e10a4c73d188ddd52ccf21ecc9e39d50a6af51")
+
+    variant("serial", default=True, description="Enable Serial NetCDF diagnostics")
+
+    depends_on("fortran", type="build")  # generated
+
+    depends_on("mpi")
+    depends_on("netcdf-fortran@4.5.2:")
+
+    def cmake_args(self):
+        args = [self.define_from_variant("ENABLE_NCDIAG_SERIAL", "serial")]
+
+        args.append(self.define("CMAKE_C_COMPILER", self.spec["mpi"].mpicc))
+        args.append(self.define("CMAKE_Fortran_COMPILER", self.spec["mpi"].mpifc))
+
+        return args
diff --git a/configs/templates/gsi-ncdiag-1.1.3/envrepo/repo.yaml b/configs/templates/gsi-ncdiag-1.1.3/envrepo/repo.yaml
new file mode 100644
index 000000000..dd634d06c
--- /dev/null
+++ b/configs/templates/gsi-ncdiag-1.1.3/envrepo/repo.yaml
@@ -0,0 +1,3 @@
+repo:
+  namespace: envrepo
+  api: v1.0
diff --git a/configs/templates/gsi-ncdiag-1.1.3/spack.yaml b/configs/templates/gsi-ncdiag-1.1.3/spack.yaml
new file mode 100644
index 000000000..d37c0d061
--- /dev/null
+++ b/configs/templates/gsi-ncdiag-1.1.3/spack.yaml
@@ -0,0 +1,23 @@
+# Add-on environment to provide gsi-env with gsi-ncdiag@1.1.3
+# See https://github.com/JCSDA/spack-stack/issues/1938
+#
+spack:
+  concretizer:
+    unify: when_possible
+
+  view: false
+  include: []
+
+  specs:
+  - gsi-env ^crtm@3.1.2 # match unified-dev template
+
+  repos: [$env/envrepo]
+
+  packages:
+    all:
+      buildable: false
+    gsi-ncdiag::
+      require: ['@1.1.3']
+      buildable: true
+    gsi-env:
+      buildable: true