Weather Observations Flashcards
METAR? (Not an acronym)
Aviation Routine Weather Report
Aviation Routine Weather Report? (METAR)
- Primary Observation Code
2. for reporting surface meteorological data.
How often are METARs transmitted?
At least once per hour.
Automated Observation?
Weather observation report from an automated system without a certified weather observer.
Manual Observation?
Weather observation report from a certified weather observer.
Wind?
- Horizontal motion of air
2. Past a given point.
Prevailing visibility?
- Representative visibility at the station.
- Greatest distance that can be seen throughout at least half of the horizon circle
- 180 non-contiguous degrees.
Obscuration?
- Any atmospheric phenomenon
- Not precipitation
- reduces horizontal visibility.
Sky Condition?
- State of the sky in terms of:
- Sky cover
- Layers
- and (Layers) associated heights, ceiling, and cloud type.
Layer
- Array of clouds/obstructions
2. whose bases are at about the same level
Dew Point
- required air temp at
- constant pressure and
- constant water-vapor content
- for saturation to occur
Altimeter setting
- The altitude above mean sea level
2. of an aircraft on the ground.
Virga
- Precipitation that evaporates before reaching the surface.
What 2 things can Virga indicate?
- Icing hazard
2. Microburst
How are METARs organized?
- Standardized format in
2. groups of information.
When a piece of information isn’t available for a METAR, how is that unavailable information reported?
“Missing”
EX- Wind Missing
What 3 pieces of information are always contained in a METAR?
RVR
Present weather
Remarks
RVR?
Runway visual range
What are 3 automated weather observation systems?
- AWOS
- ASOS
- AWSS
AWOS
Automated Weather Observing System
ASOS
Automated Surface Observing Systems
AWSS
Automated Weather Sensor System
What is the phraseology for a SPECI report?
Special Report
Are SPECI reports scheduled?
No
What is the specific criteria for a SPECI report?
Important Changes have been observed.
Can all automated equipment evaluate SPECI criteria?
No
When is an aircraft mishap reported under SPECI Criteria, and what can stop that report?
- Upon notification of the aircraft mishap
2. Unless there’s been an intervening observation.
When should a SPECI report be filed regarding ceiling?
- If the ceiling forms or dissipates below,
- decreases to less than,
- or increases to equal or
- exceed specific altitudes.
A SPECI report should be filed if the ceiling forms or dissipates below, decreases to less than, or increases to equal or exceed what 5 possible altitudes?
- 3,000’
- 1,500’
- 1,000’
- 500’
- Lowest standard approach minimum published in NOS US Instrument Procedures
OR - 200’
In what 3 circumstances should a SPECI report be filed concerning precipitation?
Hail, Freezing precipitation, and/or ice pellets
- begin
- end
- change intensity.
NOS?
National Ocean Service
When should a SPECI report be filed due to runway RVR?
- decreases to less than
- or increases to greater to
- 2400’
- in the last 10 mins
Can the Military generate SPECI reports due to RVR?
No
When should a SPECI report be filed due to Sky Condition?
- layer of clouds or obscurations appears
2. below 1,000’
When should a SPECI report be filed due to Squalls?
Whenever they occur.
When should a SPECI report be filed due to Thunderstorms?
- When they begin
2. When they end
When should a SPECI report be filed due to Tornado, Funnel Cloud, or Waterspout?
- When observed
2. When it ends/stops being observed.
When should a SPECI report be filed due to visibility?
Surface visibility decreases below, or increases above: 1. 3 SM 2. 2 SM 3. 1 SM 4. Lowest NOS minimum OR 5. If none, 1/2 SM
When should a SPECI report be filed due to Volcanic Eruption?
When observed
When should a SPECI report be filed due to Wind Shift?
- Wind direction changes 45 degrees or more
- in less than 15 mins
- wind speed is 10 knots or more during the shift.
When should a SPECI report be filed due to misc factors?
- Any other critical meteorological situation
2. Based on observer’s opinion.
What station ID will be used in a SPECI/METAR report?
4-letter ICAO airport ID
What does the first letter of an ICAO airport ID designate?
Large country code
What letter is used as the country code for the Continental US in the ICAO code?
“K”
What date and time is recorded for a SPECI report?
When SPECI criteria was met
In what time is a METAR/SPECI report set?
UTC
In what format is the time of a METAR/SPECI report indicated?
(DAY)(HOUR)(MINUTE)
What 3 report modifiers are used in a SPECI/METAR report and what do they mean?
AUTO: Automated
COR: Corrected
No modifier: Manual/Augmented observation
What do the first 3 digits in a Wind section of a SPECI/METAR report indicate?
- Wind direction relative to true north
2. VRB: variable direction less than 6kts
What do the 4th and 5th digit in the wind section of a SPECI/METAR report indicate?
Wind speed
If the 6th digit in the wind section of a SPECI/METAR report is a “G” what does it mean?
Gusts
How would “wind calm” be sown in a METAR/SPECI report?
00000KT
How would gusts of 15 knots be shown on the METAR/SPECI report?
xxxxxG15KT
What does the “visibility section of a SPECI/METAR report indicate?
Surface visibility in SM
When is RVR reported on a METAR/SPECI?
When visibility is:
- 1SM or less and or
- RVR is 6,000’ or less
What 3 characters may the Runway Visual range on a METAR/SPECI be prefaced by and what do they mean?
P: “Greater than”
M: “Less than”
V: “variable between two values”
What are the 3 Qualifiers of the Present Weather listed on a SPECI/METAR report?
- Intensity
- proximity
- Descriptor
What are the 3 types of Weather Phenomena of the Present Weather listed on a SPECI/METAR report?
- Precipitation
- Obscuration
- Other
What are the 4 Intensity or proximity qualifiers that can be on the Present Weather section of a METAR/SPECI report?
- Light
- Moderate
- Heavy
- VC (in the vicinity)
METAR/SPECI report ==> Present Weather ==> Qualifier ==> Descriptor ==> MI meaning?
MI = Shallow
METAR/SPECI report ==> Present Weather ==> Qualifier ==> Descriptor ==> PR meaning?
PR = Partial
METAR/SPECI report ==> Present Weather ==> Qualifier ==> Descriptor ==> BC meaning?
BC = Patches
METAR/SPECI report ==> Present Weather ==> Qualifier ==> Descriptor ==> DR meaning?
DR = Low drifting
METAR/SPECI report ==> Present Weather ==> Qualifier ==> Descriptor ==> BL meaning?
BL = Blowing
METAR/SPECI report ==> Present Weather ==> Qualifier ==> Descriptor ==> SH meaning?
SH = Shower(s)
METAR/SPECI report ==> Present Weather ==> Qualifier ==> Descriptor ==> TS meaning?
TS = Thunderstorm
METAR/SPECI report ==> Present Weather ==> Qualifier ==> Descriptor ==> FZ meaning?
FZ = Freezing
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Precipitation ==> DZ meaning?
DZ = Drizzle
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Precipitation ==> RA meaning?
RA = Rain
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Precipitation ==> SN meaning?
SN = Snow
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Precipitation ==> SG meaning?
SG = Snow grains
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Precipitation ==> IC meaning?
IC = Ice crystals
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Precipitation ==> PL meaning?
PL = Ice pellets
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Precipitation ==> GR meaning?
GR = Hail
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Precipitation ==> GS meaning?
GS = Small hail/snow pellets
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Precipitation ==> UP meaning?
UP = Unknown precipitation
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Obscuration ==> BR meaning?
BR = Mist
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Obscuration ==> FG meaning?
FG = Fog
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Obscuration ==> FU meaning?
FU = Smoke
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Obscuration ==> VA meaning?
VA = Volcanic Ash
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Obscuration ==> DU meaning?
DU = Widespread dust
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Obscuration ==> SA meaning?
SA = Sand
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Obscuration ==> HZ meaning?
HZ = Haze
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Obscuration ==> PY meaning?
PY = Spray
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Other ==> PO meaning?
PO = Well developed dust/sand whirls
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Other ==> SQ meaning?
SQ = Squalls
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Other ==> FC meaning?
FC = Funnel cloud, tornado, waterspout
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Other ==> SS meaning?
SS = Sand storm
METAR/SPECI report ==> Present Weather ==> Weather Phenomena ==> Other ==> DS meaning?
DS = Dust storm
Present weather on a METAR/SPECI report, what does +FZRA mean?
Heavy Freezing Rain
Present weather on a METAR/SPECI report, what does -TSGR mean?
Light Thunderstorm Hail
Present weather on a METAR/SPECI report, what does MISN mean?
Shallow Snow
Present weather on a METAR/SPECI report, what does SHDZ mean?
Showers Drizzle
What are the 4 factors measured when reporting Sky Condition?
- Sky Cover
- Cloud Type
- 3-digit altitude
- Multiple layers in ascending order
What is Sky Cover?
Amount of sky hidden by clouds/obstructions.
In what fraction is Sky Cover measured?
Eighths
What are the 4 measurements of Sky Condition?
FEW - Few clouds
SCT - Scattered
BKN - Broken (ceiling)
OVC - Overcast (ceiling)
With what 3 digit number is altitude below 50’ AGL reported on a METAL/SPECI?
000
What type of reporting stations report on Cloud Type?
Manual reporting stations
What is Cloud Type TCU?
Towering Cumulus
What is Cloud Type CB?
Cumulonimbus
What code is used for Clear Skys in Automated reports?
CLR
What does a CLR report indicate?
No layers at or below 12,000’ MSL
What code is used for Clear Skys in Manual reports?
SKC
What does an SKC report indicate?
No layers
What is the code for Vertical Visibility?
VV(3 digits indicating ceiling)
EX VV002 - Indefinite Ceiling, two hundred
What is the phraseology for SKC or CLR?
- Clear, or,
2. Clear below one two thousand
What is the phraseology for FEW?
Few clouds at (altitude)
What is the phraseology for SCT?
(Altitude) scattered
What is the phraseology for BKN?
(Altitude) overcast
What is the phraseology for VV?
Indefinite ceiling (Altitude)
When broadcasting a METAR/SPECI report, what needs to be stated before lowest BKN or OVC layer?
“Ceiling” then BKN or OVC layer
What Phraseology is used if the layer is 000 and an obscuration is present?
SKY PARTIALLY OBSCURED
What Phraseology is used if the layer is 000 and there is no obstruction?
LESS THAN FIVE ZERO
What what measurement of degrees is the temperature/dew point given?
Celsius
How many digits is the Temperature/Dew Point given in and how are they separated?
- 4 digits
2. 2 pair separated by a “/”
What are the first two digits in the Temperature/Dew Point?
temperature
What are the second two digits in the Temperature/Dew Point?
dew point
What phraseology would be used if the Temperature/Dew Point
is 10/08
TEMPERATURE ONE ZERO, DEW POINT EIGHT
How are negative numbers in a measure of the Temperature/Dew Point indicated?
prefixed by an “M” for minus
How is altimeter indicated on a METAR/SPECI report?
A and 4-digits
What is the phraseology used if the altimeter indicated is A2998?
ALTIMETER TWO NINER NINER EIGHT
What remarks added to a METAR/SPECI report?
- Automated, Manual, plain language
2. Additional and maintenance data
In the remarks section of a METAR/SPECI, what do the letters B and E indicate?
B - Beginning
E - End
In the remarks section of a METAR/SPECI, what is the additional and maintenance data shown?
Sensor status indicators
Encode Shallow
MI
Encode Partial
PR
Encode Patches
BC
Encode Low Drifting
DR
Encode Blowing
BL
Encode Shower
SH
Encode Thunderstorm
TS
Encode Freezing
FZ
Encode Drizzle
DZ
Encode Rain
RA
Encode Snow
SN
Encode Snow Grains
SG
Encode Ice Crystals
IC
Encode Ice Pellets
PL
Encode Hail
GR
Encode Small hail/snow pellets
GS
Encode Unknown precipitation
UP
Encode Mist
BR
Encode Fog
FG
Encode Smoke
FU
Encode Volcanic Ash
VA
Encode Widespread dust
DU
Encode Sand
SA
Encode Haze
HZ
Encode Spray
PY
Encode Well developed dust/sand whirls
PO
Encode Squalls
SQ
Encode Funnel cloud, tornado, waterspout
FC
Encode Sand storm
SS
Encode Dust storm
DS
Decode VV002
Indefinite Ceiling two hundred
Decode VV020
Indefinite ceiling two thousand
Encode Indefinite Ceiling two hundred
VV002
Encode Indefinite ceiling two thousand
VV020
What cloud layer would describe 1/8th sky coverage?
FEW
What cloud layer would describe 3/8th sky coverage?
Scattered
What cloud layer would describe 5/8th sky coverage?
Broken
Decode SCT070 OVC080
Seven thousand scattered, ceiling eight thousand overcast
Encode six hundred overcast, ceiling eight thousand broken
OVC006 BKN080
Decode FEW003 SCT030
Three hundred few, ceiling three thousand scattered.
Encode two hundred broken, ceiling five thousand overcast.
BKN002 OVC050