weather Flashcards
stare the general characteristics in regard to the flow of air around high and low pressure system in the northern hemisphere
low pressure —inward ,upward ,and counterclockwise
hight pressure —–outward ,downward and clockwise
what is trough ?
a trough is an elongated area of relatively low atmospheric pressure
what is ridge?
a ridge is an elongated area of relatively hight atmospheric pressure
what are the standard temperature and pressure values for sea level
15 / 29.92
what are isobar
an isobar is a line on a weather chart witch connects areas of equal or constant barometric pressure
what causes the wind aloft to flow parallel to the isobar
the Coriolis force
why do surface wind generally flow across the isobar at an angle
surface friction
at what rate dose atmospheric pressure decrease with an increase in altitude
1 Hg per 1000ft
what does dew point mean
dew point is temperature to which a sample of air must be cooled to attain the state of saturation
what factor primarily determines the type and vertical extent of cloud ?
the stability of the atmosphere
during your preflight planning ,what type of meteorological information should you be aware of with respect to icing
1.location of fronts 2. cloud layers 3. freezing level 4.air temperature and pressure
what condition are necessary for structural icing to occur
visible moisture and below freezing temperature at the point moisture strikes the aircraft
name the main type of icing an aircraft may encounter in flight
structural , induction system ,and instrument icing
what action is recommended if you inadvertently encounter icing condition
leave the area of visible moisture , descending to an altitude below the cloud bases ,climbing to an altitude below the cloud base ,climbing to an altitude above the cloud tops ,or turning to a different course
what are the three stages of a thunderstorm ?
cumulus stage
mature stage
dissipating stage
state two basic ways that fog may form
cooling air to the dew point or
adding moisture to the air near the ground
why is wind shear an operational concern to pilot
can be potentially very hazardous to aircraft operations at low altitude on approach to and departing from airport
what type of information will you examine to determine if wind shear condition might affect your flight
TAF ,METAR ,(SIGMET ,convective SIGMET ),
LLWAS, PIREPs
what is the primary means of obtaining a weather briefing
the primary source is an individual briefing obtained from a briefer at the AFSS/FSS ,these briefing ,which are tailored to your specific flight are available 24hours
what are some example of other sources of weather information ?
- telephone information briefing service
- weather and aeronautical information available from numerous private industry
- direct user access terminal system (DUATS)
- in alaska ,transcribed weather broadcast (TWEB)and telephone access to the TWEB(TEL-TWEB)
where can you find a listing of AFSS/FSS and weather information number?
AFD under the FAA and NWS telephone Numbers section
what types of weather briefing are available from an AFSS/FSS briefer
- standar briefing
- abbreviated briefing
- outlook briefing
- inflight briefing
what pertinent information should a weather briefing include?
a. adverse conditions
b. VFR flight not recommended
c. synopsis
d. current condition
e. enroute forecast
f. destination forecast
g. wind aloft
h. notices to airmen(NOTAMs)
i. ATC delay
describe the basic elements of a METAR
- type of report
- ICAO station identifier
- data and time of report
- modifier
- wind
- visibilty
- runway visual range
- weather phenomena
- sky condition
- temp/dwepoint
- altimeter
- remarks
