Weather Theory
The standard temperature & pressure values for sea level
What is 15C (59F) and 29.92 Hg
What is a METAR
An aviation routine weather report - the weather observer's interpretation of the weather conditions at a given site and time (transmitted every hour)
Name 3 sources of weather information
Foreflight, WX Brief, AviationWeather.gov, FSS, DUATS (Direct User Access Terminal System), PIREPs, ATIS/AWOS, etc.
Name the different levels of clouds
Low (sfc to 6,500)
Middle (6,500 - 20,000)
High (20,000 +)
Vertical (based low-med with tops extending high)
What is the "recipe" for a thunderstorm
Sufficient water vapor (moisture)
Unstable lapse rate
Initial lifting action
The factor that primarily determines the type & vertical extent of clouds
What is the stability of the atmosphere
What is a PIREP and where are they found
A Pilot Report - existing conditions at a certain time/place. Available from ATC, FSS, and on the internet/Foreflight.
Types of weather briefings available from an FSS briefer
Standard briefing, Abbreviated briefing, Outlook briefing, Inflight briefing
Clouds form when
What is Air becomes saturated
Name 3 types of icing & how icing occurs
Rhime, Clear, Mixed
When visible moisture is present and surface (of aircraft) at or below 0C.
When the temperature and dew point are close together, this type of weather is likely
What is visible moisture in the form of clouds, dew, or fog. These are also ideal conditions for carburetor icing.
A SIGMET is?
Advisory of weather that is potentially hazardous to all aircraft. Valid for 4 hours.
Automatic Terminal Information Service
Name 3 types of fog
Radiation Fog, Advection Fog, Upslope Fog, Steam Fog, Precipitation Fog
Name the 3 stages of a Thunderstorm
Cumulus, Mature, Dissipating
The standard lapse rate is
What is 2C per 1,000 ft.
3 types of AIRMETs are?
Sierra: IFR conditions and/or extensive mtn obscuration.
Tango: moderate turbulence, sustained surface winds of 30kts or greater, and/or non-convective low-level wind shear
Zulu: moderate icing (provides freezing level heights)
How do you obtain weather enroute?
FSS (on 122.2), ATIS, HIWAS, Datalink Weather, ATC (workload permitting), Foreflight
Name 4 types of clouds
stratus, stratocumulus, nimbostratus
altostratus, altocumulus
cirrus, cirrostratus, cirrocumulus
cumulus, towering cumulus, cumulonimbus
What is Wind Shear
A sudden drastic shift in wind speed and/or direction that may occur at any altitude in a vertical or horizontal plane
The types of fronts
Cold front, Warm front, Occluded front, Stationary front
A CWA is?
Center Weather Advisory - an aviation warning for use by aircrews to anticipate and avoid adverse weather conditions in the enroute and terminal environments (already or expected to cause impact within 2 hours)
What type of information is provided in an ATIS broadcast?
Time of broadcast, ceiling, visibility, obstructions to visibility, temperature, dew point, wind direction & velocity, altimeter, other remarks, instrument approach/runway in use
What is the disc shaped cloud that forms commonly over the tops of mountains (seen around Taos often!)
Altocumulus Standing Lenticular Cloud - winds exceeding 40kts!
Name 3 types of Turbulence
Mechanical, Convective, Mountain Wave, Clear Air, Frontal, Wake,