Enroute Icing

### Produced by The COMET® Program

### Introduction » About the Lesson

This lesson presents a process for forecasting enroute aviation icing in the context of a case over the CONUS. It focuses on the icing forecast procedure up to the point of issuing products. This involves gaining situational awareness of areas with icing potential, making first forecasts of their locations and flight levels, and comparing them to NWP forecasts, adjusting as needed.

After completing the lesson, users should be able to:

- Identify data products that are useful for identifying and forecasting icing
- Describe associated temperature and moisture profiles that can lead to organized types of icing
- Use observational data and NWP analyses to determine if icing is present
- Develop an icing “first forecast,” identifying expected areas, flight levels, and severity of icing based on initial conditions
- Use the Numerical Weather Prediction (NWP) forecast to modify the first forecast as appropriate

Learners should be familiar with the following before taking this lesson:

- Aircraft icing, including conditions conducive to its formation, such as air temperature, moisture, cloud microphysics, and the formation of supercooled cloud droplets
- Pilot reporting systems (PIREPs) and icing advisories issued as locally required to warn pilots of hazardous flight conditions
- Model products used in aviation forecasting