diff --git a/preferences.xml b/preferences.xml
index 9827a6d68..5b070cfb3 100644
--- a/preferences.xml
+++ b/preferences.xml
@@ -251,6 +251,7 @@ Started September 2000 by David Megginson, david@megginson.com
   <dewpoint-sea-level-degc type="double">5</dewpoint-sea-level-degc>
   <pressure-sea-level-inhg type="double">29.92</pressure-sea-level-inhg>
   <wind-from-heading-deg type="double">270</wind-from-heading-deg>
+  <turbulence-norm type="double">0.0</turbulence-norm>
   <clouds>
    <status>true</status>
    <layer n="0">