Enroute Icing

### Produced by The COMET® Program

### Step 1: Diagnosing Locations of Icing » METAR Surface Observations » Data

Here is the METAR for the Chicago O’Hare International Airport (KORD) at 13 UTC 26 February 2011. That’s the same time as the surface map we saw earlier.

METAR KORD 261251Z 05007KT 2.50SM -SN FEW009 OVC014 M03/M04 A2995 RMK AO2 SLP141 P0001 T10331039

#### Question

Here’s a portion of the surface weather depiction used specifically for aviation and issued every three hours, valid at 12 UTC 26 February 2011. Included are the ceiling in hundreds of feet, the visibility in statute miles, cloud coverage, and weather type, all obtained from METAR observations. Where does it indicate an icing risk?

Circle areas of freezing precipitation in red, and areas of very light to light snow in orange.

Tool: | Tool Size: | Color:
--- | --- | ---
Pen Eraser |  |

The light to very light snow locations (✱ and ✱✱) are enclosed in orange. The two stations with freezing precipitation (~) are enclosed by the red contour. Much of the area over and west of the service area has surface conditions that indicate potential icing, especially from Kansas City to St. Louis, MO where the freezing drizzle indicates likely moderate icing.