Met Course Flashcards
What is an Air Mass?
A large body of air with similar weather characteristics
What does AM stand for?
Arctic Maritime
What does PM stand for?
Polar Maritime
What does rPM stand for?
Returning Polar Maritime
What does TM stand for?
Tropical Maritime
What does PC stand for?
Polar Continental
What does TC stand for?
Tropical Continental
What weather comes with a Polar Maritime (PM) air mass?
Summer: Cool and Showery
Winter: Cold/ Wintry showers
What weather comes with a Arctic Maritime (AM) air mass?
Summer: Cool and Maritime
Winter: Very cold/ Wintry showers
What weather comes with a returning Polar Maritime(rPM) air mass?
Summer:
Wet/Cloudy
Winter: Wet/Cloudy
What weather comes with a Tropical Maritime (TM)air mass?
Summer: Warm/Cloudy/Fog
Winter: Mild/Cloudy/Fog
What weather comes with a Tropical Continental air mass?
Summer: Hot and Dry
What weather comes with a Polar Continental air mass?
Summer: Cloudy
Winter: Very cold
What is a front?
Boundary between 2 air masses
What is a warm front?
Warm air replacing cold air
What is a cold front?
Cold air replacing warm air
What is an occluded front?
Cold front catches up with warm front
What is a Trough?
An elongated area of relatively low pressure.
Which way does the wind turn in a low pressure system?
Anti-clockwise
Which way does the wind turn in a high pressure system?
Clockwise
What does METAR stand for?
Meteorological aerodrome report
What does TAF stand for?
Aerodrome Forecast
What 3 elements in a METAR are calculated automatically?
- Wind, direction, speed n gusts
- Temperature and dew point
- Pressure
What 3 elements in a METAR are manually inputted?
- Visibility
- Present weather
- Cloud
What does ATIS stand for?
Air Traffic Information Service
How often is a METAR produced?
Every 30 minutes
What times are METARs issues?
10 to the hour and
20 past the hour
The mean wind direction and speed is for how long a period?
10 minutes
Wind direction is reported from?
A) True North
B) Compass North
C) Magnetic North
True North
For a gust to be reported it must exceed the mean wind by?
10 knots or more
Wind gust is the?
Maximum 3 second “peak” taken from the 10 minute period
When shall a wind variation be reported?
The total variation in the previous 10 minutes is 60 degrees or more but less than 180 degrees and the average wind speed is greater than 3 kts
When is the wind reported calm?
When the speed is less than 01kt
How do you report wind speeds greater than 99kts?
P99kt
What is the standard height for wind measurements at Aerodromes?
10m AGL
Where should wind sensors be located?
Ina location representative of the whole runway and capture undisturbed wind.
What height should visibility be observed?
- 5m
* Slant error may occur if observed from an increased height*
What is prevailing visibility?
The greatest visibility reached within at least 1/2 the horizon circle or 1/2 of the surface of the aerodrome.
When should the minimum visibility be reported?
When the vis in one direction is less than 1500m or less than 50% of the prevailing wind.
What do you report when the lowest visibility is in more than one direction?
Report the most operational significant one
What do you report when the vis is fluctuating rapidly and no prevailing vis can be determined?
Lowest vis reported with no indication of direction.
When the visibility is less than 800 metres it should rounded down to the nearest?
50 metres
When the visibility is 800 metres or more but less than 5000m it should rounded down to the nearest?
100 metres
When the visibility is 5000 metres or more but less than 10km it should rounded down to the nearest?
1,000 metres
If the visibility is less than 50 metres (e.g. 35m) how shall it be encoded?
0000
Define RVR
Measurement of the Horizontal visibility along the runway
When is RVR reported?
When minimum visibility or RVR is less than 1500m
How do you report RVR less than 50m metres?
M0050
How would you report an RVR greater than 2000m?
P2000
When the RVR is less than 400 metres it should rounded down to the nearest?
25 metres
When the RVR is between 400 and 800 metres it should rounded down to the nearest?
50 metres
When the RVR is greater than 800 metres it should rounded down to the nearest?
100 metres
Define in the vicinity
Within 8km of the aerodrome Reference point
TS takes Precedence over any other precipitation, True or False?
True.
BC means?
Patches
MI means?
Shallow
SG means?
Snow Grains
PL means?
Ice Pellets
GR means?
Hail
GS means?
Small hail/snow pellet
BR means?
Mist
What is the code for sleet?
SNRA
Or
RASN
What visibility is Mist reported and what is it’s relative Humidity?
5000-1000m
95%+
Temp/DP 1 degree or less difference
When is Fog(FG) reported?
Vis is less than 1000m
RH is 100%
When is Haze reported and what is it’s RH?
5000m or less
Less than 95%
What is a Squall (SQ)?
Wind rise by 16kts+ increasing to 22kts+ and sustained by 1 minute
What does // mean
U/S or missing present weather sensor
What does UP mean?
Unidentified Percipitation
What does FZUP mean?
Freezing Unidentified precipitation
What height is cloud reported till?
Up to but not including 5,000ft
Which 2 clouds are specified in the METAR?
TCU and CB
When is CB or TCU specified in the METAR?
After cloud amount and height
Cloud is rounded down to the nearest?
100ft
Few is how many Oktas
1-2
SCT is how many Oktas
3-4
BKN is how many Oktas
5-7
OVC is how many Oktas
8
Is cloud height above sea level or AGL?
AGL
When would a cloud base of 5,000ft or higher be reported?
If it is the base of a TCU or CB
How do you report a cloud base less than 100ft?
000
For a second layer of cloud what is required?
Must be 3 oktas or more than 1st layer.
3rd layer can be entered provided…
Amount is 5 oktas or more
What does NSC mean?
No significant cloud below 5,000ft and no TCU/CB
VV/// is?
Vertical visibility height not measured or sky obscured.
When a TS is reported a CB must be reported true or False?
True.
What are the 5 conditions for CAVOK
- Prevailing vis 10km +
- No minimum Vis
- No cloud below 5,000ft/Min sector Alt.
- No TCU or CB present
- No weather phenomena at or in Vicinity of the AD
Temperature is rounded up or down? To the hottest degree.
Up
How many digits is the temperature?
2
If DP is not available what is it replaced with?
//
A temperature of -0.5 to-0.1 is coded as?
M00
Temperature between 0.0 to 0.4 is coded as?
00
QFE is included in the METAR.
True or False?
False