Definition
A summary of significant weather hazards affecting flight, including Convective SIGMETs, SIGMETs, AIRMETs, Center Weather Advisories (CWAs), and urgent pilot reports (Urgent PIREPs). Air Traffic Control advises pilots when any of this information is current along their route of flight, and pilots may then request the specific details from the controller or obtain them from a Flight Service Station or other source.
Plain English
A bundle of weather warnings about things that could make flying dangerous — thunderstorms, icing, turbulence, low visibility, and similar hazards. If any of these warnings apply to where you're flying, ATC will let you know one exists and you can ask for the details.
Context Anchor
Pilots may hear or receive Hazardous Weather Information during preflight planning, from flight service, through weather briefings, on aviation weather displays, or from air traffic control while in flight.
Derivation
Hazardous comes from hazard, meaning a danger or risk. Information means facts that are given or received. Together, the phrase means facts provided to warn pilots about weather risks.
Why Pilots Care
Helps pilots decide whether to delay, reroute, or cancel a flight to avoid conditions that could lead to loss of control or damage.
Grounding Statement
If a weather report tells you about conditions that could threaten the safety of the flight, it is serving as Hazardous Weather Information.
Intuition Check
Do not read this as just any bad-weather comment. In aviation, Hazardous Weather Information means safety-relevant weather information that may require pilot action or a flight-planning change.
Example Sentence 1
Cessna 24Bravo, hazardous weather information for the Chicago area is available on Flight Watch or by contacting Flight Service.
Example Sentence 2
In flight, the pilot requested updated hazardous weather information to check for changing conditions ahead.