Verification for Philip, SD

Sunday July 6th:
NWS Forecast: 89F
My Forecast: 87F
Actual High: 89F
Difference: 2 degrees

Monday, July 7th morning low:
NWS: 64F
ME: 65F
Actual: 63F
Difference: 2 degrees

Monday, July 7th high:
NWS: 89F
ME: 80F
Actual: 86F
Difference: 6 degrees

NWS Error: 4 degrees
My Error: 10 degrees

What happened?

I ignored the GFS 850 mb temperatures and got burned. Lesson: When the GFS 850 mb temps are warmer than the NAM, the high is likely to go warmer than the 850 mb temps forecast by the NAM.