Higher ice crystal concentrations made it into the unsaturated layer below 500mb then lasted about 1 km. Some of the sublimation from the ice in the higher ice concentrations took place in the saturated layer, then fell into the unsaturated layer. Lower bound of about 3500 feet where the ice crystals can seed into liquid layer below. 3500 feet is the minimum distance and 5000 feet as the maximum distance between 2 layers that you can count on introducing ice all the way through an unsaturated layer. WFO MKX used the seeder-feeder idea to forecast a change in precipitation type.
Middle portion look for warm layer or unsaturated layer.
There is a warm layer, however if ice is not introduced into the warm layer it doesn't matter what the maximum warm layer temperature is, it's going to be a freezing drizzle outcome if surface layer is supercooled. Bottom surface cold layer. Freezing rain would be the result at the surface assuming no cloud is overhead seeding the lower cloud. 31 Summary of Top-Down approach 32 OKC sounding Assess this sounding. After falling into the cold layer at lower levels it will freeze as ice pellets.