Add fv3_warm and fv3_nest yamls back in

- Add DO_NEST back into stage.py
- Add back in reworked yamls for fv3_warm and the nest

Refs NOAA-EMC#2475

parm/stage/fv3_nest.yaml.j2

@@ -0,0 +1,17 @@
+{% set cycle_HH = current_cycle | strftime("%H") %}
+{% set cycle_YMD = current_cycle | to_YMD %}
+{% set cycle_YMDH = current_cycle | to_YMDH %}
+{% set ntile = 7 %}
+fv3_nest:
+    mkdir:
+        - "{{ COM_ATMOS_RESTART_PREV }}"
+    copy:
+        {% if EXP_WARM_START %}
+        {% for ftype in ca_data fv_core.res fv_srf_wnd.res fv_tracer.res phy_data sfc_data %}
+        - ["{{ BASE_CPLIC }}/{{ CPL_ATMIC }}/{{ cycle_YMDH }}/{{ MEMDIR }}/atmos/{{ cycle_YMD }}.{{ cycle_HH }}0000.{{ ftype }}.tile{{ ntile }}.nc", "{{ COM_ATMOS_RESTART_PREV }}/{{ cycle_YMD }}.{{ cycle_HH }}0000.{{ ftype }}.nest0{{ ntile-5 }}.tile{{ ntile }}.nc"]
+        {% endfor %} # ftype
+        {% else %}
+        {% for ftype in gfs_data sfc_data %}
+        - ["{{ COM_ATMOS_INPUT }}/{{ ftype }}.tile{{ ntile }}.nc", "{{ COM_ATMOS_INPUT }}/{{ ftype }}.nest02.tile{{ ntile }}.nc"]
+        {% endfor %} # ftype
+        {% endif %} # cold-start

parm/stage/fv3_warm.yaml.j2

@@ -0,0 +1,15 @@
+{% set cycle_HH = current_cycle | strftime("%H") %}
+{% set cycle_YMD = current_cycle | to_YMD %}
+{% set cycle_YMDH = current_cycle | to_YMDH %}
+fv3_warm:
+    mkdir:
+        - "{{ COM_ATMOS_RESTART_PREV }}"
+    copy:
+        {% for ftype in ["coupler.res", "fv_core.res.nc"] %}
+        - ["{{ BASE_CPLIC }}/{{ CPL_ATMIC }}/{{ cycle_YMDH }}/{{ MEMDIR }}/atmos/{{ cycle_YMD }}.{{ cycle_HH }}0000.{{ ftype }}", "{{ COM_ATMOS_RESTART_PREV }}"]
+        {% endfor %}
+        {% for ftype in ["ca_data", "fv_core.res", "fv_srf_wnd.res", "fv_tracer.res", "phy_data sfc_data"] %}
+        {% for ntile in range(1, ntiles + 1) %}
+        - ["{{ BASE_CPLIC }}/{{ CPL_ATMIC }}/{{ cycle_YMDH }}/{{ MEMDIR }}/atmos/{{ cycle_YMD }}.{{ cycle_HH }}0000.{{ ftype }}.tile{{ ntile }}.nc", "{{ COM_ATMOS_RESTART_PREV }}"]
+        {% endfor %} # ntile
+        {% endfor %} # ftype

ush/python/pygfs/task/stage.py

@@ -66,6 +66,9 @@ def determine_stage(self, stage_dict: Dict[str, Any]) -> List[str]:
         if stage_dict.DO_ICE:
             stage_sets.append("ice.yaml.j2")
 
+        if stage_dict.DO_NEST:
+            stage_sets.append("fv3_nest.yaml.j2")
+
         return stage_sets
 
     @logit(logger)