An AIRMET Sierra is issued to warn pilots of:
Why →
AIRMETs come in three types: Sierra (IFR conditions and mountain obscuration), Tango (turbulence, strong surface winds, low-level wind shear), and Zulu (icing and freezing levels). AIRMET Sierra indicates ceilings expected below 1,000 feet and/or visibility below 3 miles over 50% or more of an area.The trap →
Three AIRMET types. Three different hazards. S = sky obscured/IFR. T = Turbulence. Z = Zero degrees (freezing/icing). Mixing them up is the classic test trap.SOURCE → FAA Aviation Weather Services / PHAK Chapter 13CHECKED APR 21ACS III.A.K1MED