feat: Add check for existence of weather data

NAERSTADMO.py

@@ -89,6 +89,11 @@ def create_dataset():
                 )
                 subprocess.run(f"rm {tmpfile_path}tmpfile.nc", shell=True)
 
+    # Ensure that model is not run if weather data is not available
+    if not os.path.exists(f"{tmpfile_path}weather_data.nc"):
+        print(f"{tmpfile_path}weather_data.nc does not exist. Exit.")
+        return
+
     subprocess.run(f"rm {outtmp_path}final_*", shell=True)
 
     create_saturation()