First of all, jealous I'm not there to ski and argue car temps vs web sites with you!
I find car temp gauges to be way less accurate, especially when the car is stationary, than the weather stations I have access too. I have also found the Sugarbush web site temps to be very accurate, as they too are taking a direct feed from a high end weather station that they own and have placed around the mountain (same one's they rely on to make snow).
I think the issue is that, even with cloud cover, solar radiation will impact the cars external temp reading. It would be interesting to see how residual heat from the engine block effects it too.
Now, if you had a legit thermometer I would stand down...
Josh is obviously right that there's an inversion and a warm layer causing non-snow. But the warm layer is much higher than 1,800' base elevation, and right now, even above summit elevation.
I know someone on this fourm who car says it 10 degrees all time
Summer or winter
Sugars b is awesome ski snowboard experience
I need to get soon
With the Warren Miller voucher hopefully