Fire was set to a number of establishments, and the smoke from these fires is being seen on weather radar displays. That's a smoke plume from the fires in Gatlinburg. Smoke from Minneapolis radar after firesThe top half of the picture shows reflectivity, which is the radar product that commonly detects precipitation and precipitation types. This is a product called correlation coefficient that will differentiate between rain drops and “non-hydrometeors,” or things that aren’t rain. The streak of blue falls in line with the weak echoes on reflectivity, indicating that this is indeed smoke being lofted into the air.