diff --git a/lib/xmet/sounding.py b/lib/xmet/sounding.py
index 59477ff..6754a87 100644
--- a/lib/xmet/sounding.py
+++ b/lib/xmet/sounding.py
@@ -1,6 +1,8 @@
 import datetime
 import shapely
 
+from typing import Self
+
 from xmet.db     import Database, DatabaseTable, DatabaseOrder
 from xmet.coord  import COORD_SYSTEM
 from xmet.list   import nearest
@@ -47,9 +49,6 @@ class SoundingSample(DatabaseTable):
     def is_saturated(self) -> bool:
         return self.humidity >= 100.0
 
-class SoundingParameters():
-    pass
-
 class Sounding(DatabaseTable):
     __slots__ = (
         'id', 'station', 'timestamp_observed', 'timestamp_released',
@@ -185,13 +184,15 @@ class Sounding(DatabaseTable):
 
         return series
 
-    def derive_parameters(self) -> SoundingParameters:
-        temp_line   = self.follow_temp()
-        dry_adiabat = follow_dry_adiabat(self.samples[0].temp,
-                                         self.samples[0].pressure)
+class SoundingParameters():
+    @staticmethod
+    def from_sounding(sounding: Sounding) -> Self:
+        temp_line   = sounding.follow_temp()
+        dry_adiabat = follow_dry_adiabat(sounding.samples[0].temp,
+                                         sounding.samples[0].pressure)
 
-        saturated_mr_line = follow_saturated_mixing_ratio(self.samples[0].dewpoint,
-                                                          self.samples[0].pressure)
+        saturated_mr_line = follow_saturated_mixing_ratio(sounding.samples[0].dewpoint,
+                                                          sounding.samples[0].pressure)
 
         lcl = dry_adiabat.intersect(saturated_mr_line, SeriesIntersection.LESSER)