diff --git a/lib/xmet/sounding.py b/lib/xmet/sounding.py
index c703ab6..12a2684 100644
--- a/lib/xmet/sounding.py
+++ b/lib/xmet/sounding.py
@@ -185,9 +185,8 @@ class Sounding(DatabaseTable):
 
         return series
 
-    def find_lfc(self, temp: float, pressure: float) -> tuple[float]:
+    def find_lfc(self, temp: float, pressure: float, temp_line: Series) -> tuple[float]:
         moist_adiabat = follow_moist_adiabat(temp, pressure)
-        temp_line     = self.follow_temp()
 
         pairs = nearest(sorted(moist_adiabat.keys(), reverse=True),
                         sorted(temp_line.keys(),     reverse=True))
@@ -198,9 +197,8 @@ class Sounding(DatabaseTable):
             if v1 > v2:
                 return v1, pair[0]
 
-    def find_el(self, temp: float, pressure: float) -> tuple[float]:
+    def find_el(self, temp: float, pressure: float, temp_line: Series) -> tuple[float]:
         moist_adiabat = follow_moist_adiabat(temp, pressure)
-        temp_line     = self.follow_temp()
 
         pairs = nearest(sorted(moist_adiabat.keys(), reverse=True),
                         sorted(temp_line.keys(),     reverse=True))
@@ -212,6 +210,7 @@ class Sounding(DatabaseTable):
                 return v1, pair[0]
 
     def derive_parameters(self) -> SoundingParameters:
+        temp_line   = self.follow_temp()
         dry_adiabat = follow_dry_adiabat(self.samples[0].temp,
                                          self.samples[0].pressure)
 
@@ -219,8 +218,8 @@ class Sounding(DatabaseTable):
                                                           self.samples[0].pressure)
 
         lcl = dry_adiabat.intersect(saturated_mr_line, SeriesIntersection.LESSER)
-        lfc = self.find_lfc(lcl[0], lcl[1])
-        el  = self.find_el(lfc[0], lfc[1])
+        lfc = self.find_lfc(lcl[0], lcl[1], temp_line)
+        el  = self.find_el(lfc[0], lfc[1], temp_line)
 
         params = SoundingParameters()
         params.lcl = lcl