CAA NZ CPL Meteorology flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

METAR

Routine aerodrome weather report issued at fixed intervals (usually half-hourly or hourly), reporting wind, visibility, weather, cloud, temperature, dewpoint and QNH.

SPECI

Special aerodrome weather report issued when conditions change significantly between routine METAR reports, e.g. onset of thunderstorms, fog or a marked wind change.

TAF

Terminal aerodrome forecast giving expected conditions over a stated validity period, using TEMPO for temporary fluctuations and BECMG for permanent changes.

TREND forecast

Short forecast appended to a METAR or SPECI covering the following 2–3 hours, using BECMG, TEMPO or NOSIG to describe expected changes.

GRAFOR

Graphical area forecast used in New Zealand, depicting expected cloud, weather, visibility, turbulence and freezing level by region over defined validity periods.

SIGMET

Warning of weather hazardous to all aircraft such as severe turbulence, severe icing, volcanic ash or tropical cyclones; typically valid four hours, six for volcanic ash.

AIRMET

Advisory of moderate hazards affecting low-level operations, including moderate turbulence, moderate icing, mountain obscuration and widespread reduced visibility.

AIREP

Pilot report of actual weather encountered in flight, such as turbulence, icing or windshear, transmitted to ATS for dissemination to other aircraft.

VOLMET

Continuous HF or VHF broadcast of METAR and TAF information for specified aerodromes, allowing en-route pilots to obtain current weather without voice contact.

ATIS

Automatic terminal information service broadcast giving current aerodrome weather, QNH, runway in use and other operational information, updated on significant change.

Wind gust group

Format dddssGggKT: direction, mean speed and gust speed in knots; e.g. 24015G28KT means 240 degrees at 15 knots gusting 28.

VRB wind

Variable wind direction reported when the direction varies significantly or is indeterminate, usually with light winds; no meaningful mean direction exists.

9999 visibility

METAR visibility code meaning 10 kilometres or more; four-digit groups below 5000 report visibility in metres.

RVR

Runway visual range, reported as Rxx/dddd with optional trend D (decreasing) or U (increasing); required when visibility or RVR falls below specified values.

Cloud amount codes

FEW means 1–2 oktas, SCT 3–4, BKN 5–7 and OVC 8; the lowest BKN or OVC layer defines the ceiling.

CAVOK

Code meaning visibility 10 km or more, no cloud below 5000 ft or the highest MSA, and no significant weather; replaces visibility, cloud and weather groups.

Weather intensity prefix

A plus sign denotes heavy and a minus sign light; no prefix denotes moderate; e.g. +SHRA is heavy rain showers, -FZRA light freezing rain.

Temperature-dewpoint spread

Difference between temperature and dewpoint; a spread of 2°C or less indicates high likelihood of fog, mist or low cloud formation.

Severe icing

Icing intensity that seriously affects aircraft handling or performance and may cause structural damage; avoid the area and report the encounter.

Colour code GRN

Aerodrome colour state indicating no cloud below 1500 ft and visibility of 8 km or more; used for quick assessment of aerodrome conditions.

Part 174

New Zealand Civil Aviation rule governing certification of meteorological service organisations; MetService is the certified aviation meteorological provider.

Pilot weather briefing duty

Before flight, the pilot must obtain weather information appropriate to the route and update it in flight when conditions differ from forecast or forecasts become invalid.

SIGMET mandatory triggers

SIGMET must be issued for volcanic ash, tropical cyclones, severe turbulence, severe icing, severe mountain waves and other phenomena hazardous to all aircraft.

Known icing flight

Flight into known icing conditions is permitted only when the aircraft is certificated and equipped for icing; forecasts and warnings inform this decision.

VFR weather minima

Minimum visibility and cloud separation requirements vary by airspace class; meteorological information must be obtained to confirm VFR can be maintained.

TAF amendment

When a TAF is amended (AMD) or corrected (COR), the new version supersedes earlier issues; pilots must re-check before departure and intermediate stops.

AIREP reporting duty

Significant weather encounters such as severe turbulence, icing, windshear or volcanic ash should be reported to ATS for dissemination and possible SIGMET issue.

Himawari satellite

Geostationary satellite providing high-resolution imagery of the Asia-Pacific, with 10-minute full disk and 2.5-minute target scans for convective and fog monitoring.

NWP ensemble

Set of numerical forecasts from slightly perturbed initial conditions; the spread among members indicates forecast uncertainty and confidence.

AMDAR

Automated aircraft-derived meteorological data of wind and temperature, transmitted to ground systems to improve model initialisation and short-term forecasts.

Nowcasting

Short-range forecasting out to about six hours using radar, satellite and surface observations, particularly useful for tracking convective development and fog.

WAFS

ICAO World Area Forecast System providing global gridded forecasts of upper winds, temperatures and significant weather for flight planning.

Wellington VAAC

Volcanic Ash Advisory Centre responsible for issuing ash advisories for the New Zealand region; SIGMET for volcanic ash is mandatory when ash is present.