initialize the values with None

aman/sys/WeatherModel.py

@@ -9,6 +9,9 @@ class WeatherModel:
     def __init__(self, gaforId, weather : Weather):
         self.Gafor = gaforId
         self.Weather = weather
+        self.Altitudes = None
+        self.Directions = None
+        self.Windspeeds = None
         self.WindDirectionModel = None
         self.WindSpeedModel = None
         self.LastWeatherUpdate = None