International Data Flashcards
List the different types of international alphanumeric current and forecast data:
- Metar
- TAF
- Sigmet
- Airmet
- Pirep
- Area Forecast
- Upper Winds
- Convective outlook
What 2 items aren’t contained in american metars?
Wind shear and Recent codes
In an American METAR, a routine obs can be between ______ and _____
H+45 and H
An M preceding the visibility value means?
Less than
Automated stations without a precipitation descriptor are identified as _____
A01
Automated stations with a precipitation descriptor are identified as _____
A02
What does the peak wind in the metar signify?
the maximum instantaneous wind speed since the last METAR that exceeded 25kts
What will lightning be shown as on the metar based on its distance?
A. wtn 5 NM of ALP will be TS
B. btn 5-10 NM VCTS
C more than 10 but <30 NM will be reported as LTNG DSNT in remarks with direction.
What is the definition of ALP?
Airport Location point
The permanent reference point defined by the latitude and longitude published in the Airport facility directory
What are the 4 different types of lightning strikes reported?
CG
IC
CC
CA
What is the value for frequent lightning?
FRQ: 1-6 flashes a minute
OCNL, CONS
With the beginning and ending of precip, are the coded remarks required in SPECI?
no
At locations where SPECIs are not taken what is the remark?
NO SPECI
For snow increasing rapidly, what is the remark used and what is the measurement?
SNINCR and its formatted in inches fallen/inches on the ground
The hourly precipitation amount is coded in
Hundreds of an inch. 0000 = trace
What does CAVOK need?
- no cloud below 5000ft, or MSA whichever is higher and no CB
- Vis 6 or more
- No precip, TS, shallow fog or drifting snow
What additional data is included in certain military base forecasts?
- lowest altimeter for a certain period
- Icing layer
- turbulence layer
- Max and min forecast temperature
- nature of observation (human or automated)
The US area forecast must be used in conjunction with:
Airmet Sierra bulletin (IFR)
FAs are issued ___ times a day for each of the ___ areas of the contiguous US plus _______
-3
-6
Gulf of Mexico and Caribbean
the FA consists of:
- A 12 hour forecast plus a 6 hour outlook
- Synopsis section
- VFR clouds and weather section
The alaskan FAs are issued ____ times daily
4
The description of forecast weather in American FAs differs from canadian FAs in the following ways:
- Areas of cloud and weather are described for each state without reference to a synoptic system
- Cloud bases are given as in METARs
- Cloud tops are only given for BKN or OVC layers and only the highest layer
- Vis below 3 are only given in associated airmet sierra
For the contiguous 48 states, the location of weather phenomena will be stated with respect to:
2 letter state identifiers and delineated by VORs
Convective sigmet bulletins are issued at:
hour +55
How long are convective sigmets valid for?
2 hours, followed by a 2-6 hour outlook
What are the 4 criteria for issuing a convective sigmet?
- Severe thunderstorm
- embedded thunderstorms
- Line of thunderstorms
- Intense thunderstorms
Non convective sigmets are valid for:
a maximum of 4 hours
What are the 4 criteria for a non convective sigmet?
- Severe icing
- Severe or extreme turbulence
- duststorm or sandstorm reducing vis below 3
- Volcanic ash
remind the pilot that another briefing may be advisable , especially if any of the following applies:
- Time of departure is more than 4 hours away
- Complete briefing was not provided
- the time between the briefing and the ETA is more than 4 hours
What is the function of an american airmet?
It advises of weather, other than convective, that may be hazardous to single engine and other light aircraft conducting VFR flight.
what are the 3 american airmets?
Airmet Sierra (IFR conditions) Airmet Tango (Turbulence) Airmet Zulu (Icing)
how many times are american airmets issued daily and how long are they valid for?
issued 4 times, valid for 6 hours plus a 6 hour outlook.
Airmet Sierra is issued for:
- Ceilings less than 1000ft and/or vis less than 3 miles affecting over 50% of an area
- Extensive mountain obscuration
Airmet Tango is issued for:
- Moderate turbulence
- Sustained surface winds of 30kts or more
Airmet Zulu is issued for
- Moderate Icing
- Freezing levels
If the criteria is not met, will an airmet still be issued?
yes!
What are the differences between canadian and international pireps
- Indicators are coded for WX
- Flight visibility will be the first entry in the WX field
- Different abbreviations may be used
International FBs represent forecast winds over the world for every _____ degree of latitude and longitude
5
What is the difference between the FB and FD bulletins?
FB has 3 digits for the wind speed, and negative temps are indicated by the letter M rather than a -
The US convective outlook is a ______ day outlook
3
Note the following with regards to american pirep codes
- useful cloud and weather information is under /sk /wx
- miscoding is common
- Not all fields may be reported
- it can be helpful to have a list of identifiers nearby
The 5 risk categories in the convective outlook are:
- No significant thunderstorms
- General thunderstorms
- Slight Risk
- Moderate Risk
- High risk
Users can assess from the data from the convective outlook:
- Geographic areas where severe weather is expected to occur
- perceived levels of threat
- Areas where extreme severe weather is expected.
