diff --git a/lib/xmet/sounding.py b/lib/xmet/sounding.py
index a98549f..b355b05 100644
--- a/lib/xmet/sounding.py
+++ b/lib/xmet/sounding.py
@@ -266,7 +266,7 @@ class SoundingParams():
                            dewpoint_line.nearest(lcl[1]),
                            lcl[1])
 
-        moist_adiabat = follow_moist_adiabat(tv2, lcl[1])
+        moist_adiabat = follow_moist_adiabat(tv2-1, lcl[1])
 
         lfc = moist_adiabat.intersect(virtual_temp_line,
                                       SeriesIntersection.GREATER)