diff --git a/lib/xmet/raob.py b/lib/xmet/raob.py
index f081b31..ea76898 100644
--- a/lib/xmet/raob.py
+++ b/lib/xmet/raob.py
@@ -262,6 +262,12 @@ class RAOBObs():
             if len(self.tokens) < i+3 or self.tokens[i][-1] == '=':
                 break
 
+            #
+            # Stop parsing tokens at the tropopause.
+            #
+            if self.tokens[i][0:2] == '88':
+                break
+
             sample = self.parse_sample_tokens(self.tokens[i:i+3])
 
             if sample is None: