Aviation Weather Reports and Forecasts Flashcards
(31 cards)
What does 1. METAR, 2.SPECI and 3. TAF mean?
- Aviation Routine Weather Report
- Aviation Selected Special Weather Report
- Aerodrome forecast
metars are issued in telex form usually every -
And updated every -
If the weather changes during the intervals of sending out routine reports, then the new weather information is distributed as a -
Criteria for this is changes in -
Three hours
half hour
Speci
Wind, Visibility, Weather and low cloud
If any element cannot be observed the group in which it would have been encoded is replaced by the symbol -
////
Wind on a METAR and SPECI is indicating in -
Degrees True to. the nearest ten
When it forecasted that the maximum wind speed will exceed the mean speed by 10 knots or more, the maximum wind speed is indicated by adding -
G(gusting) followed by the gusting speed
IF during the __ minute period preceding the observation, the total variation in wind direction is __ degrees or more and the mean wind speed is greater than _ knots the observed two extreme directions between which the wind has varied is indicated in a clockwise order. Example: 240V015
IF during the 10 minute period preceding the observation, the total variation in wind direction is 60 degrees or more and the mean wind speed is greater than 3 knots the observed two extreme directions between which the wind has varied is indicated in a clockwise order
The U, D or N in a METAR or SPECI report relavent to the visibility and RVR segment mean -
U for increasing visibility
D for decreasing visibility
N for no change
When actual RVR values are outside the measuring range of the observing equipment in use, the following procedures apply:
- RVR more than _____m, Code _
- RVR less than __m - Code _
When actual RVR values are outside the measuring range of the observing equipment in use, the following procedures apply:
- RVR more than 1500m, Code P
- RVR less than 50m - Code M
VC in the present weather segment indicate:
In the vicinity, within 8km.
CAVOK means:
- Visibility greater than 10km
- No cloud below 5 000ft or the MSA, whichever is the greater, and no CBs.
- No significant weather
RE followed by two letter indicates:
Recent weather
Trend forecast:
BECMG, TEMPO and NOSIG could be followed by -
AT(at)
FM(from)
TL(until)
TAFs are updated every -
3 hours
Segments that are unique to a TAF:
- Date and time period. The date and time of the with a Z followed by the time period.
- The added “PROB” in addition to BECMG, TEMPO and NOSIG.
- Relevant to temperature, TX to indicate maximum and TN to indicate minimum. This will be followed by time, and the time will be followed by the letter Z.
- Icing data is preceded by the number 6. Followed by the icing code, height AGL and thickness layer.
- Turbulence code is same as icing, but preceded by the number 5.
Both METAR and TAF indicate surface wind in -
degrees true to the nearest ten
TEMP means?
Less than an hour
Relevant to RVR:
U, D and N means respectfully?
U - Increasing
D - Decreasing
N - No change
The next items in the METAR (d, e, f and g) are the observed wind information. Firstly, the direction of the wind given in degrees true, rounded up or down to the nearest 10 degrees, (d), and then the wind speed in knots, (e), which is a mean speed taken over a __ minute period. However, if a gust is observed which is at least __ knots more than the mean wind speed, then a gust figure, (g), comes after the mean wind; this gust figure is preceded by the letter G, (f).
The next items in the METAR (d, e, f and g) are the observed wind information. Firstly, the direction of the wind given in degrees true, rounded up or down to the nearest 10 degrees, (d), and then the wind speed in knots, (e), which is a mean speed taken over a 10 minute period. However, if a gust is observed which is at least 10 knots more than the mean wind speed, then a gust figure, (g), comes after the mean wind; this gust figure is preceded by the letter G, (f).
variability of the wind. Variability of direction is included when the wind direction, over the preceding __ minutes, has changed by __° or more. The letter V will appear between these two extremes. If there is no wind, the coding, 00000KT, will be used. If the wind direction cannot be defined then VRB (for variable) replaces the direction.
variability of the wind. Variability of direction is included when the wind direction, over the preceding 10 minutes, has changed by 60° or more. The letter V will appear between these two extremes. If there is no wind, the coding, 00000KT, will be used. If the wind direction cannot be defined then VRB (for variable) replaces the direction.
METAR:
Visibility is indicated by 0000 if it is less than -
- meters
METAR:
If the RVR is more than the maximum reportable value of _____ metres, the code _ is used in front of the visibility value
If the visibility is less than __ m then the prefix __ will be used
If the RVR is more than the maximum reportable value of 1500 metres, the code P is used in front of the visibility value
State the meaning of each:
Descriptors:
MI - BC - BL - SH - TS - FZ - PR -
MI - Shallow BC - Patches BL - Blowing SH - Shower(s) TS - Thunderstorms FZ - Freezing (Supercooled) PR - Partial (covering part of aerodrome)
State the meaning of each:
Precipitation:
DZ - RA - SN - IC - PL - GR - GS - UP - PY -
DZ - Drizzle RA - Rain SN - Snow IC - Ice Crystals (Diamond Dust) PL - Ice Pellets GR - Hail GS - Small hail - (<5 mm in diameter and/or snow pellets) UP - Unknown Precipitation PY - Spray
State the meaning of each:
Obscuration:
BR - FG - FU - VA - DU - SA -
BR - Mist FG - Fog FU - Smoke VA - Volcanic Ash DU - Widespread Dust SA - Sand HZ - Haze
