Definition
An AIRMET issued for icing conditions and freezing levels. AIRMET Zulu describes areas of moderate airframe icing forecast to occur and provides the altitudes of the freezing level across the affected region.
Plain English
A weather advisory that warns pilots where ice is likely to form on the aircraft and tells them at what altitude the air becomes cold enough to freeze water.
Context Anchor
Seen in aviation weather briefings, flight planning tools, and FAA weather products before and during a flight.
Derivation
AIRMET stands for Airmen's Meteorological Information. The label 'Zulu' comes from the NATO phonetic alphabet, used here simply as a category code — the icing and freezing-level version of the AIRMET. AIRMETs are split into three named categories (Sierra for IFR/mountain obscuration, Tango for turbulence, Zulu for icing) so pilots can quickly identify which hazard is being reported.
Why Pilots Care
Moderate icing reduces lift, increases drag, and can make control difficult, so pilots must plan to avoid or exit these areas.
Grounding Statement
If your route passes through clouds or precipitation in freezing air, AIRMET Zulu is the warning that ice may form on the aircraft.
Intuition Check
Do not read “Zulu” here as Zulu time or UTC. In AIRMET Zulu, “Zulu” names the icing and freezing-level category.
Example Sentence 1
During the preflight briefing, the pilot noted an AIRMET Zulu for moderate icing between 8,000 and 16,000 feet along the route.
Example Sentence 2
Before takeoff we checked the AIRMET Zulu to confirm the freezing level was well above our planned cruise altitude.