diff --git a/spells/Air1.tex b/spells/Air1.tex
index 9548efe74f7927cdba41d83e377bfc189d9885c3..f69a0413ef488ca4fb07f25f0be63b43f170e87e 100644
--- a/spells/Air1.tex
+++ b/spells/Air1.tex
@@ -21,6 +21,8 @@
 
     The air only covers \arabic{spelllevel} square -- enough for a doorway, or small tunnel.
     It dissipates after a couple of turns, or less if wind is present.
+
+    Casting the spell outdoors raises the \gls{tn} by 1, casting it on a windy day raises it by 3, and casting the spell in a storm raises the \gls{tn} by 5.
   }
 
 \spell{Bubble}% Name