Be more tolerant of missing elements of height values

lib/xmet/raob.py

@@ -275,12 +275,12 @@ class RAOBObs():
         # Ignore tokens where height is not known.
         #
         if num == '///':
-            return None
+            return dict()
 
         pressure = self.code_to_pressure(code)
 
         if pressure is None:
-            return None
+            height = None
         elif pressure == 1000:
             height = self.calc_1000mb_height(float(num))
         elif pressure <= 850 and pressure > 700:
@@ -641,7 +641,7 @@ class RAOBReader():
                 timestamp = data['timestamp']
                 samples   = data['samples']
 
-                sounding = self.sounding(station, timestamp)
+                sounding = self.sounding(station, timestamp[0:4])
 
                 for data in samples:
                     pressure = data.get('pressure')