During what weather phenomenon would AIRMET Zulu be issued?

AIRMET Zulu is specifically issued to advise pilots of potential icing conditions in the atmosphere that could pose a risk to flight safety. This alert is crucial because ice can accumulate on aircraft wings and control surfaces, adversely affecting performance and handling. Typically, AIRMET Zulu indicates that moderate icing is anticipated, which, although not as severe as conditions that might warrant a SIGMET, still requires pilot awareness and caution. This information is vital for flight planning and decision-making, as pilots must be ready to take appropriate measures, such as altering altitude or flight path, to ensure safety.

Severe icing is a critical component of what AIRMET Zulu addresses, making it the correct choice in the context of this question. The other options relate to phenomena that could trigger different types of alerts; for instance, severe turbulence would be covered by AIRMET Tango, while volcanic ash and strong winds fall under the categories governed by SIGMETs. Each of these alerts plays a specific role in communicating different hazards to pilots.