diff --git a/priv/repo/migrations/20260419222624_add_kind_to_grid_tasks.exs b/priv/repo/migrations/20260419222624_add_kind_to_grid_tasks.exs
new file mode 100644
index 00000000..8de82280
--- /dev/null
+++ b/priv/repo/migrations/20260419222624_add_kind_to_grid_tasks.exs
@@ -0,0 +1,24 @@
+defmodule Microwaveprop.Repo.Migrations.AddKindToGridTasks do
+  use Ecto.Migration
+
+  # `kind` splits the queue between forecast-hour work (the 18 f01..f18 rows
+  # Rust has owned since Phase 2) and analysis-hour work (f00, which Elixir
+  # still runs because it carries the native-level duct merge, NEXRAD, and
+  # commercial-link enrichment). Stream A of the Phase 3 migration plan
+  # ports those enrichments to Rust and flips f00 onto this queue too.
+  # Forecast rows default to 'forecast' so existing producers keep working
+  # during the transition.
+  def change do
+    alter table(:grid_tasks) do
+      add :kind, :string, null: false, default: "forecast"
+    end
+
+    create index(:grid_tasks, [:status, :kind])
+
+    # Replace (run_time, forecast_hour) uniqueness with a three-column key so
+    # an analysis row and a forecast row for f00 can coexist during the
+    # cutover. Post-cutover the analysis row replaces f00 outright.
+    drop_if_exists unique_index(:grid_tasks, [:run_time, :forecast_hour])
+    create unique_index(:grid_tasks, [:run_time, :forecast_hour, :kind])
+  end
+end