Obtaining Weather Information Flashcards
What is the primary means of obtaining a weather briefing?
individual briefing obtained from a briefer at the AFSS/FSS
Sources of weather information?
a - Telephone information briefing service (TIBS, AFSS)
b - Weather and aeronautical information from numerous private industry sources
C- DUATS
d- TWEB (alaska)
What pertinent information should a weather briefing include?
- adverse conditions
- VFR flight not recommend
- synopsis
- Current conditions
- Enroute forecast
- Destination forecast
- Winds aloft
- NOTAMs
- ATC delay
EFAS?
Enroute Flight Advisory Service
Specifically designed to provide enroute aircraft with timely and meaningful weather advisories pertinent to type of flight, route, altitude. EFAS is also a central collection and distribution point for PIREPS. Communication available between 5,000 and 17,500 MSL on 122.0. Known as “flight watch”
What is HIWAS?
Hazardous In flight Weather Advisory Service -
continuous broadcast of in flight weather advisories including Aviation Weather Warnings, SIGMETs, Convective SIGMETs, Center weather advisories, AIRMETs, and urgent PIREPs.
What is a METAR?
Aviation routine weather report is an observer’s interpretation of the weather conditions at a given site and time.
Elements of a METAR?
a. Type - routine and SPECI
b. Station identifier
C. Date and time
d. Modifier
e. Wind
f. Visibility
g. Runway Visual Range
h. Weather phenomena
i. Sky condition
j. Temperature/dew point group
k. altimeter
PIREP elements and info?
Required elements - type of report, location, time, flight level (in MSL), aircrft type, and at least one weather element encountered. Distance and vis in SM; all other distances in NM. UTC time. Routine (UA) and Urgent (UUA)
What are TAFs?
Terminal aerodrome forecasts
Concise statement of the expected meteorological conditions within a 5 SM radius from the center of an airport’s runway complex during a 24 hour time period.
Elements of TAF?
a. type - routine TAF, or amended TAF AMD
b. ICAO ident.
c. Date and time
d. valid period date and time
e. forecasts - wind vis, sig weather, sky condition, non convective low level wind shear, change indicators, probibility
What is an aviation area forecast
A forecast of visual meteorological conditions (VMC), clouds, and general weather conditions over an area the sie of several states. Must be used along with inflight weather advisories to determine forecast enroute weather and to interpolate conditions at airports where no TAFs are issued, i order to understand the complete weather picture. FAs are issued 3 times a day by the AWC for each of the 6 areas of the contiguous 48 states.
What information is provided in an aviation area forecast?
Area forecasts = FA cover airspace between surface and 45,000 AMSL
a. synopsis: weather affecting the FA area during the 18 hour valid period
b. Clouds and weather: description of the clouds and weather for the first 12 hour period for each state or group, includes -
- –Cloud amount (SCT, BKN, OVC) for clouds with bases higher than or equal to 1,000 feet AGL and below FL 180
- –Cloud bases and tops (AMSL)
- – Precipitation
- – Visibility between 3 and 6 SM and obstructions to vis
- – sustainted surface winds = or > 20kt
c. 12 to 18 hour categorical outlook: IFR, MVFR, VFR, including expected precip and or obstructions to vis
What are WST, WS, WA?
Inflight aviation weather advisories. Forecasts that advise enroute aircraft of development of potentially hazardous weather. All heights are in MSL, except CIG which are AGL
WST - convective SIGMET
WS - SIGMET
WA - AIRMET
What is a convective SIGMENT?
A convective SIGMET (WST) implies severe or greater turbulence, severe icing and low level wind shear. It may be issued for any convective situation which the forecaster feels is hazardous to all categories of aircraft. Issued hourly at H +55.
a. severe thunderstorm due to: surface winds greater than or = 50 kt
- – hair greater or = 3/4 inches in diameter
- – tornados
b. embedded thunderstorms
c. line of thunderstorms
d. thunderstorms producing greater than or equal to heavy precip that affects 40 percent or more of an area at least 3,000 square miles
What is a SIGMET?
WS advises of non convective weather that is potentially hazardous to all aircraft. WS are issued for the six areas corresponding to the FA areas. The maximum forecast period is four hours. In the US, SIGMETs are issued when the following phenomena occur or are expected:
a. severe icing not associated with a thunderstorm
b. severe or extreme turbulence or clear air turbulence (CAT) not associated with thunderstorms
c. dust storms or sandstorms lowering surface or in flight visibilities to below 3 miles.
d. volcanic ash