ANSWERS TO REVIEW QUESTIONS
NAVMETOCCOMINST 3143.1, Aerodrome Forecast (TAF) Code.
TAFs are transmitted at 6-hour standard intervals at 0300. 0900, 1500, and 2100
UTC, and are valid for 24 hours.
Windshear conditions exist, but complete information cannot be reliably forecast.
Occasional moderate turbulence in clouds from 10,000 to 13,000 feet.
The lowest altimeter setting in inches expected during the forecast period.
The abbreviation "FM" is used to indicate the beginning of a change period in the
forecast. Elements in this change group supersede all elements previously
Wind speed change of IO knots or more, directional change of 30° or more (when
the mean wind speed or gusts are in excess of 15 knots), or when wind speed or
directional change results in a change of an active runway.
Significant weather is any weather that may affect the flight performance of an
air-craft. or is capable of causing injury or damage topersonnel property on the
ground, such as from icing, LLWS, lightning. etc.
Clear Air Turbulence.
NAVMETOCCOMINST 3142.1, Procedures Governing Pilot Weather Reports
Aircraft type information follows.
Severe clear air turbulence above 35,000 feet.
The message type indicator "UUA" is used in the case of an urgent PIREP
(hazardous weather encountered).