diff --git a/docs/Contributors_Guide/github_workflow.rst b/docs/Contributors_Guide/github_workflow.rst
index 161e1c44d9..cde65598f0 100644
--- a/docs/Contributors_Guide/github_workflow.rst
+++ b/docs/Contributors_Guide/github_workflow.rst
@@ -482,6 +482,7 @@ Create a feature branch
 
   .. code-block:: ini
 
+    git fetch upstream develop
     git checkout develop
 
 * Verify the current development branch is active by running:
diff --git a/docs/Contributors_Guide/testing.rst b/docs/Contributors_Guide/testing.rst
index 1548dbe147..28574df4d7 100644
--- a/docs/Contributors_Guide/testing.rst
+++ b/docs/Contributors_Guide/testing.rst
@@ -37,12 +37,6 @@ permissions, navigate to the METplus directory, then call pytest::
     cd METplus
     pytest internal/tests/pytests
 
-Some of the tests use your default location for writing temporary files,
-typically `/tmp`. If you do not have write permissions this may cause an
-error. To override this behaviour you can specify the default directory::
-
-    pytest --basetemp=${METPLUS_TEST_OUTPUT_BASE}/tmp internal/tests/pytests
-
 A report will be output showing which pytest categories failed.
 To view verbose test output, add the **-vv** argument::
 
diff --git a/internal/tests/pytests/conftest.py b/internal/tests/pytests/conftest.py
index 968f96b736..c42b83635f 100644
--- a/internal/tests/pytests/conftest.py
+++ b/internal/tests/pytests/conftest.py
@@ -13,25 +13,48 @@
 
 from metplus.util import config_metplus
 
-output_base = os.environ.get('METPLUS_TEST_OUTPUT_BASE')
+output_base = os.environ.get("METPLUS_TEST_OUTPUT_BASE")
 if not output_base:
-    print('ERROR: METPLUS_TEST_OUTPUT_BASE must be set to a path to write')
+    print("ERROR: METPLUS_TEST_OUTPUT_BASE must be set to a path to write")
     sys.exit(1)
 
 try:
-    test_output_dir = os.path.join(output_base, 'test_output')
+    test_output_dir = os.path.join(output_base, "test_output")
     if os.path.exists(test_output_dir):
-        print(f'Removing test output dir: {test_output_dir}')
+        print(f"Removing test output dir: {test_output_dir}")
         shutil.rmtree(test_output_dir)
 
     if not os.path.exists(test_output_dir):
-        print(f'Creating test output dir: {test_output_dir}')
+        print(f"Creating test output dir: {test_output_dir}")
         os.makedirs(test_output_dir)
 except PermissionError:
-    print(f'ERROR: Cannot write to $METPLUS_TEST_OUTPUT_BASE: {output_base}')
+    print(f"ERROR: Cannot write to $METPLUS_TEST_OUTPUT_BASE: {output_base}")
     sys.exit(2)
 
 
+@pytest.fixture(scope="session", autouse=True)
+def custom_tmpdir():
+    """! Set the default output location for temp files produced by pytest
+    to METPLUS_TEST_OUTPUT_BASE env var. Causes default pytest fixtures,
+    such as tmpdir_factory, to write temp files to this dir.
+
+    A sub directory named 'pytest_tmp' is created to ensure there will never
+    be name conflicts between files created by default pytest fixture and
+    other methods for writing temp files.
+    """
+    original_var = os.environ.get("PYTEST_DEBUG_TEMPROOT", None)
+    output_base = os.environ.get("METPLUS_TEST_OUTPUT_BASE")
+    temp_base = os.path.join(output_base, "pytest_tmp")
+
+    os.environ["PYTEST_DEBUG_TEMPROOT"] = temp_base
+    if not os.path.exists(temp_base):
+        os.mkdir(temp_base)
+    yield
+    # Restore original value, if existed
+    if original_var:
+        os.environ["PYTEST_DEBUG_TEMPROOT"] = original_var
+
+
 @pytest.hookimpl(tryfirst=True, hookwrapper=True)
 def pytest_runtest_makereport(item, call):
     """! This is used to capture the status of a test so the metplus_config
@@ -58,19 +81,19 @@ def metplus_config(request):
     config = metplus_config.
     """
     script_dir = os.path.dirname(__file__)
-    args = [os.path.join(script_dir, 'minimum_pytest.conf')]
+    args = [os.path.join(script_dir, "minimum_pytest.conf")]
     config = config_metplus.setup(args)
     yield config
 
     # don't remove output base if test fails
     if request.node.rep_call.failed:
         return
-    config_output_base = config.getdir('OUTPUT_BASE')
+    config_output_base = config.getdir("OUTPUT_BASE")
     if config_output_base and os.path.exists(config_output_base):
         shutil.rmtree(config_output_base)
 
 
-@pytest.fixture(scope='function')
+@pytest.fixture(scope="function")
 def metplus_config_files():
     """! Create a METplus configuration object using minimum_pytest.conf
     settings and any list of config files.The metplus_config fixture is
@@ -79,10 +102,11 @@ def metplus_config_files():
     metplus_config_files as an argument to the test function and pass in a list
     of config files to it. Example: config = metplus_config_files([my_file])
     """
+
     def read_configs(extra_configs):
         # Read in minimum pytest config file and any other extra configs
         script_dir = os.path.dirname(__file__)
-        minimum_conf = os.path.join(script_dir, 'minimum_pytest.conf')
+        minimum_conf = os.path.join(script_dir, "minimum_pytest.conf")
         args = extra_configs.copy()
         args.append(minimum_conf)
         config = config_metplus.setup(args)