What is the weather term for snow and dust mixture? An old pilot friend of mine told me today a story that I thought was interesting.

He said that he was flying into Wichita, KS a couple decades ago and was listening to the ATIS when the weather report indicated snerd.  He called up the approach controller and asked what snerd was and the controller stated it was a mixture of the blowing snow and dust coalescing making a big mess.  The pilot stated he broke out of the clouds and all he saw was a brown mess all over the place.

Does anyone know if this is actually called snerd? If not, what is the correct term?
I lived and flew in North Dakota for about three years. While I was there, people talked about (and I experienced) the delightful mixture of snow and dirt called snirt. It can be the result of plowing sanded roads, and also can be caused by the high winds that come out of Canada blowing dirt from fields onto areas still covered in snow. Google image search has some good examples.

I have a feeling that's what was described by your friend. It appears in Wikipedia's list of types of snow, but as far as I am aware it is not an FAA or NOAA term.