diff --git a/lib/xmet/thermo.py b/lib/xmet/thermo.py
index aaee26b..a98e101 100644
--- a/lib/xmet/thermo.py
+++ b/lib/xmet/thermo.py
@@ -106,8 +106,6 @@ def loft_parcel(start_temp: float,
     dewpoint, pressure value, will be dispatched to obtain the lapse rate
     for each height.
     """
-    sx_last      = None
-    sy_last      = None
     last_height  = None
 
     temp     = start_temp