diff --git a/download.ml b/download.ml
index fe76db3..657aa75 100644
--- a/download.ml
+++ b/download.ml
@@ -4,7 +4,7 @@ open Common
 
 module Urls = struct
   let base_url = "https://nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/prod"
-  let forecast_dir = sprintf !"%s/gfs.%{Forecast_time#yyyymmdd_slash_hh}/" base_url
+  let forecast_dir = sprintf !"%s/gfs.%{Forecast_time#yyyymmdd_slash_hh}/atmos/" base_url
 
   let grib_file fcst_time levels hour =
     let fcst_hr = Forecast_time.hour_int fcst_time in