Definition
Weather conditions that make flight more difficult, more hazardous, or operationally restricted. In instrument flying, this typically includes thunderstorms, icing, turbulence, low ceilings, reduced visibility, strong or gusty winds, and wind shear.
Plain English
Bad flying weather. Anything in the sky or near the ground that makes a flight harder, riskier, or off-limits without extra care or different equipment.
Context Anchor
Seen in preflight planning, instrument flying, weather briefings, and decisions about whether to continue, divert, delay, or cancel a flight.
Derivation
Adverse' comes from Latin 'adversus', meaning 'turned against' or 'opposing'. So 'adverse weather' is literally weather that is working against the flight rather than helping it.
Why Pilots Care
Recognizing adverse weather allows pilots to delay flights, choose alternates, or avoid conditions that can lead to loss of control.
Grounding Statement
A clear route can become unsafe when weather along it makes seeing, controlling the aircraft, or landing much harder than expected.
Intuition Check
Adverse weather does not only mean a violent storm. In aviation, even ordinary-looking weather can be adverse if it reduces safety or makes the flight harder than the pilot, aircraft, or conditions can safely handle.
Example Sentence 1
The pilot reviewed the forecast and noted several areas of adverse weather along the planned route, including embedded thunderstorms and forecast icing.
Example Sentence 2
In flight, the crew diverted to an alternate airport after encountering adverse weather that exceeded approach minimums.