It looks like there may be two different weather software packages using your WU stationid to report and that's causing the sawtooth graphs
00:39 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
00:40 -5.8 °C -10.4 °C 1016.8hPa NW 9.7km/h 19.3km/h 70% 0.0mm ---
00:45 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
00:47 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
00:50 -6.1 °C -10.8 °C 1017.2hPa West 9.7km/h 24.1km/h 69% 0.0mm ---
00:51 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
00:52 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
00:57 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
00:58 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
00:59 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:00 -6.2 °C -11.0 °C 1017.5hPa West 4.8km/h 12.9km/h 69% 0.0mm ---
01:03 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:06 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:08 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:09 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:10 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:15 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:16 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:20 -6.6 °C -11.6 °C 1018.5hPa NW 6.4km/h 12.9km/h 68% 0.0mm ---
01:21 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:23 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:24 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
01:25 -6.8 °C -11.7 °C 1018.5hPa NW 6.4km/h 14.5km/h 68% 0.0mm ---
01:29 -3.9 °C -6.2 °C 1005.0hPa NW 4.8km/h 4.8km/h 84% 0.0mm ---
Suspect reports highlighted above.
Best regards,
Ken