diff --git a/config/runtime.exs b/config/runtime.exs
index 8071852f..2dd013d3 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -169,13 +169,15 @@ if config_env() == :prod do
       terrain: 3,
       iemre: 3,
       narr: 6,
-      # ERA5 queues are TEMPORARILY PAUSED while we diagnose the
-      # zero-ingestion pipeline. Every poll in prod has been hitting
-      # either CDS-rejected or long-running states; no `ERA5Batch:
-      # stored` log line has ever fired. Pausing keeps the existing
-      # oban_jobs and era5_cds_jobs rows in place for inspection
-      # instead of deleting them. Flip `paused: true` to `paused:
-      # false` (or remove the key) once the root cause is fixed.
+      # ERA5 queues are DEPRECATED in favor of NARR via NarrFetchWorker
+      # (see docs/plans/2026-04-15-merra2-historical-backfill.md). The
+      # CDS pipeline never produced a single era5_profiles row in prod
+      # — every poll hit either CDS-rejected or long-running stuck
+      # states. NARR fetches anonymously from NCEI with no quota, no
+      # job queue, and the same era5_profiles table on the receiving
+      # side. These queues stay paused while the dead Era5* workers
+      # and the era5_cds_jobs table are slated for deletion in a
+      # follow-up PR.
       era5: [local_limit: 2, paused: true],
       era5_submit: [
         local_limit: 4,