Patchy haze developed overnight Sunday into Monday for much of the Grand Valley.
The haze is a result of strong gusty winds associated with a passing cold front. The winds picked up dust and dirt from Eastern Utah and carried it into the Western Slope.
After the front passed through the winds died down and the dust began to settle. The smallest particles remained suspended in the air.
Joe Ramey with the National Weather Service says it will take more winds to blow the smaller dust particles away. Ramey says the Western Slope will see winds throughout the week.