Enroute Icing

### Produced by The COMET® Program

### Step 1: Diagnosing Locations of Icing » Satellite Data » LW IR

Longwave infrared imagery gives cloud top temperature, which can be used to infer cloud water phase. Cloud top temperatures between 0° and about -22°C indicate that the cloud likely contains supercooled water. For cloud tops colder than about -22°C, ice crystals at cloud top will reduce the amount of supercooled water, reducing the risk of icing. There is one caveat. Vigorous upward motion often results in abundant snowflakes and minimal icing risk with temperatures somewhat warmer than -22°C.

Here’s the LW IR animation from approximately 00 to 1302 UTC 26 Feb. View it, making a mental note of areas that may contain supercooled water.