PHAK 13: Aviation Weather Services Flashcards
Observations
The four types of weather observations.
- Surface
- Upper air
- Radar
- Satellite
What does AWOS stand for?
Automated Weather Observing System
What does ASOS stand for?
Automated Surface Observing System
What are ASOS and AWOS?
Continuous broadcasts of weather conditions by a computer.
Reports include date, time, wind direction and speed, visibility, sky condition, temperature, dew point, and altimeter setting.
What does RVR stand for?.
Runway visual range
Surface observations information includes…
Type of report, station identifier, date and time, modifier (as required), wind, visibility, runway visual range (RVR), weather phenomena, sky condition, temperature/dew point, altimeter reading, and applicable remarks.
What does ARTCC stand for?
Air Route Traffic Control Center
What does ARTCC do?
Maintains separation between flights conducted under IFR in the en route structure.
What does ARSR stand for?
Air Route Surveillance Radar
What does ATC stand for?
Air Traffic Control
Methods by which upper air weather phenomena can be observed.
Radiosonde observations, pilot weather reports (PIREPs), Aircraft Meteorological Data Relay (AMDAR) and the Meteorological Data Collection and Reporting System (MDCRS)
What is a radiosonde?
Small cubic instrumentation package that is suspended below a six foot hydrogen- or helium-filled balloon. Once released, the balloon rises at a rate of approximately 1,000 feet per minute (fpm). As it ascends, the instrumentation gathers various pieces of data, such as air temperature, moisture, and pressure, as well as wind speed and direction. Once the information is gathered, it is relayed to ground stations via a 300 milliwatt radio transmitter.
What does AMDAR stand for?
Aircraft Meteorological Data Relay
What is AMDAR?
An international program utilizing commercial aircraft to provide automated weather observations.
What does ACARS stand for?
Aircraft Communications Addressing and Reporting System
What does ASDAR stand for?
Aircraft to Satellite Data Acquisition and Relay
What does MDCRS stand for?
Meteorological Data Collection and Reporting System
What is MCDRS?
This program collects and disseminates real-time upper-air weather observations from
participating airlines in the U.S.A.
What does ARINC stand for?
Aeronautical Radio, Inc.
What does BUFR stand for?
Binary Universal Form
What does ESRL stand for?
Earth Science Research Laboratory
What does FDAMS stand for?
Flight Data Acquisition and Monitoring System
What does TWDR stand for?
Terminal Doppler Weather Radar
The four types of radars which provide information about precipitation and wind.
- WSR-88D NEXRAD radar AKA Doppler radar.
- FAA terminal Doppler weather radar (TDWR).
- FAA airport surveillance radar.
- Airborne radar.
What does NOAA stand for?
National Oceanic and Atmospheric Administration
What does FSS stand for?
Flight Service Station
What is the primary source for preflight weather information?
The Flight Service Station (FSS)
A preflight weather briefing from an FSS can be obtained 24 hours a day by calling
1-800-WX BRIEF
Telephone numbers for FSS can be found in
- The Chart Supplement U.S. (formerly Airport/Facility Directory)
- In the United States Government section of the phone book.
What does TIBS stand for?
Telephone Information Briefing Service
What is TIBS?
Provided by FSS
Automated telephone recordings of meteorological and aeronautical information.
TIBS provides area and route briefings, airspace procedures, and special announcements.
It is designed to be a preliminary briefing tool and is not intended to replace a standard briefing from a FSS specialist.
What does HIWAS stand for?
Hazardous Inflight Weather Advisory Service
What is HIWAS?
Automated continuous broadcast of hazardous weather information over selected VOR navigational aids (NAVAIDs).
Includes advisories such as AIRMETS, SIGMETS, convective SIGMETS, and urgent PIREPs.
VORs that have HIWAS capability are depicted on aeronautical charts with an “H” in the upper right corner of the identification box.
What does TWEB stand for?
(Alaska only)
Transcribed Weather Broadcast
What is TWEB?
Continuous automated broadcast of meteorological and aeronautical data over selected low or medium frequency (L/MF) and very high frequency (VHF) omnidirectional range (VOR) NAVAID facilities.
FSS Weather Briefings
The three types of FSS weather briefings.
- Standard
- Abbreviated
- Outlook
FSS Weather Briefings
Standard Briefing
Provides the most complete information and a more complete weather picture. This type of briefing should be obtained prior to the departure of any flight and should be used during flight planning.
FSS Weather Briefings
A standard briefing provides the following information in sequential order if it is applicable to the route of flight.
- Adverse conditions
- VFR flight not recommended
- Synopsis
- Current conditions (If depature time less than 2 hours away)
- En route forecast
- Destination forecast
- Forecast winds and temperatures aloft (temperature upon request)
- NOTAMs (when requested)
- ATC delays
- Other information
FSS Weather Briefings
Abbreviated Briefing
Shortened version of the standard briefing. It should be requested when a departure has been delayed or when weather information is needed to update the previous briefing.
FSS Weather Briefings
Outlook Briefing
An outlook briefing should be requested when a planned departure is 6 hours or more away. It provides initial forecast information that is limited in scope due to the time frame of the planned flight.
Aviation Weather Reports
What does METAR stand for?
Meteorological Terminal Aviation Routine Weather Report
Aviation Weather Reports
What is a METAR?
An observation of current surface weather reported in a standard international format.
Aviation Weather Reports
When are METARs issued?
Issued hourly at 55 minutes past the hour or anytime special weather events occur.
A special METAR (SPECI) can be issued at any time between routine METAR reports.
Aviation Weather Reports
A typical METAR report contains the following information in sequential order:
- Type of report
- Station identifier
- Date and time of report
- Modifier
- Wind
- Visibility
- Weather
- Sky condition
- Temperature and dew point
- Altimeter setting
- Zulu time
- Remarks
Aviation Weather Reports
What is a SPECI?
A special report that can be given at any time to update the METAR for rapidly changing weather conditions, aircraft mishaps, or other critical information.
Aviation Weather Reports
METAR - Station identifier
Four-letter code as established by the International Civil Aviation Organization (ICAO).
Aviation Weather Reports
METAR - Date and time of report
- Six-digit group (161753Z).
- The first two digits are the date.
- The last four digits are the UTC of the METAR/SPECI. Zulu time.
Aviation Weather Reports
METAR - Modifier
Modifier—denotes that the METAR/SPECI came from an automated source or that the report was corrected. If the notation “AUTO” is listed in the METAR/SPECI, the report came from an automated source. It also lists “AO1” (for no precipitation discriminator) or “AO2” (with precipitation discriminator) in the “Remarks” section to indicate the type of precipitation sensors employed at the automated station.
When the modifier “COR” is used, it identifies a corrected report sent out to replace an earlier report that contained an error (for example: METAR KGGG 161753Z COR).
Aviation Weather Reports
METAR - Wind
Five digits (14021KT) if speed greater than 99 knots, wind is reported with six digits.
First three digits indicate the direction the true wind is blowing from in tens of degrees.
Variable, is reported as “VRB.”
The last two digits indicate the speed of the wind in knots, if wind is greater than 99 knots, indicated by three digits.
If gusting, “G” follows wind speed (G26KT).
After “G,” the peak gust is provided.
If the wind direction varies more than 60° and the wind speed is greater than six knots, a separate group of numbers, separated by a “V,” will indicate the extremes of the wind directions.
Aviation Weather Reports
METAR - Visibilty
Prevailing visibility (¾ SM) reported in statute miles as denoted by the letters “SM.”
It is reported in both miles and fractions of miles.
At times, runway visual range (RVR) is reported following the prevailing visibility.
RVR is the distance a pilot can see down the runway in a moving aircraft.
When RVR is reported, it is shown with an R, then the runway number followed by a slant, then the visual range in feet.
For example, when the RVR is reported as R17L/1400FT, it translates to a visual range of 1,400 feet on runway 17 left.
Aviation Weather Reports
METAR - Weather
Can be broken down into two different categories: qualifiers and weather phenomenon (+TSRA BR).
First, the qualifiers of intensity, proximity, and the descriptor of the weather are given.
The intensity may be light (–), moderate ( ), or heavy (+).
Proximity only depicts weather phenomena that are in the airport vicinity.
The notation “VC” indicates a specific weather phenomenon is in the vicinity of five to ten miles from the airport.
Descriptors are used to describe certain types of precipitation and obscurations.
Weather phenomena may be reported as being precipitation, obscurations, and other phenomena, such as squalls or funnel clouds.
Descriptions of weather phenomena as they begin or end and hailstone size are also listed in the “Remarks” sections of the report.
Aviation Weather Reports
METAR - Sky condition
Always reported in the sequence of amount, height, and type or indefinite ceiling/height (vertical visibility) (BKN008 OVC012CB, VV003).
The heights of the cloud bases are reported with a three-digit number in hundreds of feet AGL.
Clouds above 12,000 feet are not detected or reported by an automated station.
The types of clouds, specifically towering cumulus (TCU) or cumulonimbus (CB) clouds, are reported with their height.
Contractions are used to describe the amount of cloud coverage and obscuring phenomena.
The amount of sky coverage is reported in eighths of the sky from horizon to horizon.
Aviation Weather Reports
METAR - Temperature and dew point
The air temperature and dew point are always given in degrees Celsius (C) or (18/17). Temperatures below 0 °C are preceded by the letter “M” to indicate minus.
Aviation Weather Reports
METAR - Altimeter setting
Reported as inches of mercury (“Hg) in a four-digit number group (A2970).
It is always preceded by the letter “A.”
Rising or falling pressure may also be denoted in the “Remarks” sections as “PRESRR” or “PRESFR,” respectively.
Aviation Weather Reports
METAR - Zulu time
UTC
Aviation Weather Reports
METAR - Remarks
The remarks section always begins with the letters “RMK.”
Comments may or may not appear in this section of the METAR.
The information contained in this section may include wind data, variable visibility, beginning and ending times of particular phenomenon, pressure information, and various other
information deemed necessary.
An example of a remark regarding weather phenomenon that does not fit in any other category would be: OCNL LTGICCG.
This translates as occasional lightning in the clouds and from cloud to ground.
Automated stations also use the remarks section to indicate the equipment needs
maintenance.
Aviation Weather Reports
What does PIREP stand for?
Pilot Weather Report
Aviation Weather Reports
What is a PIREP?
Reports of actual in-flight conditions issued by pilots. The best indication of actual flight conditions.
Aviation Weather Reports
What do PIREPs contain?
Reports include location, time, altitude, sky cover, visibility, observed weather, cloud layers, temperature, wind, possible turbulence and potential icing.
Aviation Weather Reports
A PIREP is normally transmitted as an individual report but may be appended to
a…
Surface report.
Aviation Weather Reports
Item numbers “blank” through “blank” are required information when making a report, as well as at least one…
- 1
- 5
- weather phenomenon encountered
Aviation Weather Reports
What are the two types of PIREPs?
- UA - Routine report.
- UUA - Urgent report.
Aviation Forecasts
What does TAF stand for?
Terminal Aerodrome Forecast
Aviation Forecasts
What is a TAF?
Reports forecasted winds, visibility, weather, sky conditions, and temperature.
Aviation Forecasts
When are TAF reports issued?
Scheduled 24 and 30 hour TAFs are issued four times per day, at 0000, 0600, 1200, and 1800Z