Overnight Stratus Formation?

I woke up this morning and was surprised to see a shallow layer of stratus already beginning to form over the northeast portion of the Salt Lake Valley.

I thought it might be smoke in the early morning light, but after watching it for a little while, I think it's cloud.  It's a bit unusual for the first stratus in an inversion to form in this part of the valley.  Typically it happens at lower elevations and near the airport, but perhaps the distribution of cloud cover is having an effect.

As one might surmise from the photo, the atmosphere is now quite stable over the Salt Lake Valley.  The morning sounding shows temperatures increasing from -4.7ºC at the surface to 3.4ºC at 763 mb (8200 feet).

Source: RAL

We're stuck with this now for several days.

You're going to hear a lot of talk about a possible trough passage toward next weekend, but the strength, structure, timing, and implications for northern Utah vary quite a bit across the various GEFS ensemble members.  

Source: GEFS

Keep the faith.