Weather Flashcards
What is the primary means of obtaining a weather briefing?
The primary source of preflight weather briefings is a briefing from a briefer at the AFSS/FSS. These briefings are available through 1-800-WX-BRIEF.
What are some examples of other sources of weather information?
a. Weather and aeronautical information from numerous private industry sources.
b. Direct User Access Terminal System (DUATS)
Where can you find a listing of FSS and weather information numbers?
In the AFD under “FAA and NWS telephone number” section.
What type of weather briefings are available from an FSS briefer?
a. Standard Briefing
b. Abbreviated Briefing - when you need an update to a previous briefing or only one or two items.
c. Outlook Briefing - When your proposed time of departure is six or more hours from the time of the briefing.
d. Inflight Briefing - request when needed to update a preflight briefing.
What pertinent information should a weather briefing include?
a. Adverse Conditions
b. VFR Flight Not Recommended
c. Synopsis
d. Current Conditions
e. Enroute Forecast
f. Destination Forecast
g. Winds Aloft
h. Notices to Airmen
i. ATC Delays
j. Airspace conditions (TFR’s)
What is HIWAS?
Hazardous In-flight Weather Advisory Service is a continuous broadcast of inflight weather advisories. NAVAIDSs with HIWAS capability are depicted on sectionals by an “H” in the upper right corner of the ID box.
What is an ATIS?
Automated Terminal Information Service - a continuous broadcast of recorded non control information in selected high activity terminal areas. Its purpose is to improve controller effectiveness by automating the transmission of routine information.
What type of information is provided in an ATIS broadcast?
a. Time of the latest observation
b. Wind (direction & speed)
c. Visibility (distance sm)
d. Cloud Layers & Ceiling (AGL)
e. Temperature and Dewpoint
f. Altimeter
g. Instrument approach & runway in use
What is a METAR?
A routine weather observation of the conditions at a given site and time.
What information is contained in a METAR?
a. ICAO station identifier
b. date and time of report
c. wind (direction and speed)
d. visibility
e. weather phenomena
f. sky condition
g. temperature/dew point
h. altimeter
i. remarks
Describe the various types os weather observing programs now in use.
a. Manual observations - made by FAA or NWS personnel.
b. AWOS - automated weather observing system
c. ASOS/AWSS - automated surface observing system. Can be transmitted over VHF radio or the voice portion of a NAVAID.
What are PIREPs
These reports contain information concerning weather as observed by pilots in route. Required elements for all PIREPs are message type, Location, time, flight level, type of aircraft, and at least one weather element encountered.
What are terminal aerodrome forecasts?
A TAF is a concise statement of the expected meteorological conditions within a five statue mile radius from the center of an airport runway complex during a 24 hour.
What is an aviation area forecast (FA)?
An FA is a forecast of VMC, clouds, and general weather conditions over an area the size of several states. It is used to determine forecast en-route weather and to interpolate conditions at airports which do not issue TAF.
How often are aviation area forecast issued?
FA’s are issued three times a day for each of the six areas in the contiguous 48 states.
What is a convective SIGMET?
Convective SIGMET implies severe or greater turbulence, severe icing and low-level wind shear.
What conditions would require a convective SIGMET to be issued?
a. severe thunderstorms due to: surface winds greater than or equal to 50 kn, hail at the surface greater to 3/4 inches in diameter, tornadoes
b. embedded thunderstorms
c. A line of thunderstorms
d. thunderstorms that produce precipitation levels greater than or equal to heavy intensity precipitation, affecting 40% or more of an area at least 3000 mi.²
What is a SIGMET?
Advises of non-convective weather that is potentially hazardous to all aircraft. Segments are issued for the 6 areas corresponding to the FA areas. The maximum forecast is four hours.
What conditions would require a SIGMET to be issued?
a. severe icing not associated with a thunderstorm
b. severe or extreme turbulence or a clear air turbulence not associated with thunderstorms
c. Dust storms or sandstorms lowering surface or in-flight visibility’s to below 3 miles
d. Volcanic ash
What is an AIRMET?
An AIRMET is an advisory of significant weather phenomenon for conditions at intensities lower than required for issuance of SIGMETs, issued every six hours.
What conditions would require an AIRMET to be issued?
IFR, Extensive mountain obscuration, turbulence, strong surface winds, icing, and freezing levels
What are the different types of AIRMETs?
There are three different types of AIRMETs, sierra, tango, Zulu
a. airman Sierra describes IFR conditions and/or extensive mountain obscuration
b. AIRMET tango describes moderate turbulence, sustain surface winds of 30 kn or greater, and/or non-convective low-level windshear
c. AIRMET Zulu describes moderate icing and provides freezing level Heights
What is a winds temperatures aloft forecast (FB)?
Winds and temperatures aloft are forecast 4 times daily.
What valuable information can be determined from an FB?
Most favorable altitude, areas of possible icing, Temperature inversions, turbulence
What is a center weather advisory (CWA)?
An aviation warning for use by aircrews to anticipate and avoid adverse weather conditions In the en route and terminal environments. Valid for two hours
What is a convective outlook (AC)?
DAC is a flight planning tool used to avoid thunderstorms issued in day wanted day 1 to day 2 time periods, which describes the prospects for general thunderstorm activity during the following 24 hour periods
What is a surface analysis chart?
This is a computer prepared chart transmitted every three hours that covers the contiguous 48 states and adjacent areas. Provides a ready means of locating pressure systems and fronts. It also gives an overview of winds, temperatures and dewpoint temperatures at chart time
What is a radar summary chart?
Displays areas of precipitation as well as information about type, intensity, configuration, coverage, echo top, and cell movement of precipitation.
What is a winds and temperatures aloft chart?
A computer generated chart showing bot observed and forecast winds and temperatures aloft from 6,000 to 39,000 feet MSL.
What time periods does a winds and temperatures aloft chart cover?
They are 12 hour prognostication charts and are valid at 1200Z and 0000Z.
What are significant weather prognostic charts?
They portray forecasts of selected weather conditions at specified valid times (12, 24, 36, and 48 hour).
What altitude range does a low-level significant weather prog chart cover?
Surface to 24,000 feet.
What is a convective outlook chart?
This chart shows areas forecast to have the potential for any convection, and/or extreme weather events such as tornados, wind gusts 50 knots or greater, or hail 3/4 inch diameter or greater for the next three days.
What are NOTAMs ?
Notices to Airmen. Time critical information which is not printed on any aeronautical chart.
What type of information might a NOTAM contain?
Airport or runway closures, changes in the status of navigational aids, ILS’s, radar service or other essential information for planning a flight.
What are the four basic groups of NOTAMs?
a. (D) NOTAMs - pertain to en route nav aids, civil public use airports listed in the AFD, facilities, services, and procedures
b. FDC NOTAMs - regulatory information such as, changes in IFR charts, procedures, and airspace usage
c. POINTER NOTAMs - issued by a FSS to highlight or point out another NOTAM.
d. MILITARY NOTAMs - pertain to military nav aids and airports
Where can NOTAMs be obtained?
a. flight service station
b. DUATS vendor
c. authorized third party site.
What are the two major classifications of thunderstorms?
a. Air mass thunderstorm
c. Steady state thunderstorm
What is an air mass thunderstorm?
a. Results from surface heating
b. Only lasts an hour or two
c. Occur in random unstable air
What is a steady-state thunderstorm?
a. Usually forms in lines
b. Lasts for several hours
c. Produces heavy rain, winds, and possibly tornados
d. Normally associated with weather systems
Give some examples of charts and reports useful in determining the potential for and location of thunderstorms along your route.
a. Convective outlook
b. Radar summary chart
c. PIREPs
What are microbursts?
Small-scale intense downdrafts which, on reaching the surface, spread outward in all directions. They cause both horizontal and vertical wind shears which can be hazardous to all aircraft.
Where are microbursts most likely to occur?
Almost anywhere there is convective activity.
What are some basic characteristics of a microburst?
Size: less than 1 mile in diameter as it descends from the cloud base. Can extend to 2.5 miles near ground level.
Intensity: downdrafts as strong as 6,000 ft. per minute. Horizontal winds near the surface as strong as 45 kts.
Duration: Seldom longer than 15 mins.
How can microburst encounters be avoided?
Check weather forecasts ,such as TAFs and SIGMETs, for convective activity and reports, such as METARs and PIREPs, for wind shear and sudden airspeed changes in the airport area.
Define wind shear.
The rate of change of wind velocity per unit of distance. Can be vertical or horizontal.
State the areas where wind shear is most likely to occur.
a. Low-level temperature inversion
b. In a frontal zone or thunder storm
c. Clear air turbulence at high levels associated with a jet stream or strong circulation.
Why is wind shear an operational concern to pilots?
Unexpected changes in wind speed and direction can be potentially hazardous to aircraft operations at low altitudes on approach to and departing the airport. The sudden change in wind direction can cause a drastic loss of altitude.
What airplane characteristics will be observed in a wind shear with a sudden increase in headwind?
Increase in airspeed and altitude along with a nose-up pitching tendency.
What airplane characteristics will be observed in a wind shear with a sudden decrease in headwind?
Decrease in airspeed, altitude and pitch attitude.
What is the proper action from the pilot when wind shear is encountered?
For either an increase or decrease in headwind, the pilot should add power and increase pitch attitude to maintain proper airflow over the wings.
Concerning wind shear detections, what does LLWAS indicate?
Low-Level Wind Shear Alert System. It uses sensors located around an airport to compare wind direction and speed to detect a wind shear.
