diff --git a/Dockerfile b/Dockerfile
index d457af6d..155f9ded 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -31,13 +31,17 @@ RUN apt-get update \
 
 WORKDIR /tmp/wgrib2
 
+## NOTE: wgrib2 3.6.0 enabling -DUSE_PNG / -DUSE_AEC triggers a hard
+## find_package(g2c 1.9.0 REQUIRED) for NCEPLIBS-g2c, which isn't
+## installed here. Until that's addressed, the stock build stays —
+## MRMS PrecipRate (packing type 41) can't be decoded, so
+## MrmsFetchWorker is kept out of the prod cron.
 RUN wget -q --content-disposition "https://github.com/NOAA-EMC/wgrib2/archive/refs/tags/v${WGRIB2_VERSION}.tar.gz" \
       -O wgrib2.tar.gz \
   && tar xzf wgrib2.tar.gz \
   && cd wgrib2-${WGRIB2_VERSION} \
   && mkdir build && cd build \
   && cmake .. -DCMAKE_INSTALL_PREFIX=/usr/local -DCMAKE_BUILD_TYPE=Release \
-       -DUSE_PNG=ON -DUSE_AEC=ON \
   && make -j$(nproc) \
   && make install \
   && strip /usr/local/bin/wgrib2
diff --git a/config/runtime.exs b/config/runtime.exs
index e534bcbc..3abe84d4 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -215,10 +215,13 @@ if config_env() == :prod do
          # Hourly cron caused overlapping/failed runs because one full sweep
          # exceeds a 60-minute window.
          {"5 */3 * * *", Microwaveprop.Workers.PropagationGridWorker},
-         # MRMS refreshes the PrecipRate cache that AsosAdjustmentWorker
-         # overlays onto the score grid. Both must run together — an ASOS
-         # nudge without a fresh MRMS frame reverts to HRRR-only rain.
-         {"*/2 * * * *", Microwaveprop.Workers.MrmsFetchWorker},
+         # MrmsFetchWorker is intentionally absent: the prod wgrib2 build
+         # doesn't have the PNG decoder (DRT 5.41) that MRMS PrecipRate
+         # uses, so every fetch failed with "packing type 41 not
+         # supported". AsosAdjustmentWorker gracefully handles an empty
+         # MRMS cache — the rain overlay is a nice-to-have, the ASOS
+         # nudge still runs on its own. Re-add once the Dockerfile
+         # installs NCEPLIBS-g2c + rebuilds wgrib2 with -DUSE_PNG=ON.
          {"*/10 * * * *", Microwaveprop.Workers.AsosAdjustmentWorker},
          {"*/15 * * * *", Microwaveprop.Workers.PropagationPruneWorker},
          {"*/30 * * * *", Microwaveprop.Workers.BackfillEnqueueWorker,