General Flashcards
The layers of the atmosphere
Troposphere
Stratosphere
Mesosphere
Exosphere
The part of the earths atmosphere which contains all the elements of the weather is:
The Troposphere
The earths surface is heated by
Short wave solar radiation
Air moving horizontally is influenced by the Coriolis force which is caused by
Rotation of the earth
Heat transfer from molecule to molecule without significant movement of the molecules is called:
Conduction
When surface temperatures rise due to daytime heating. This heating effect is transmitted aloft by:
Convection
Diurnal Range in temperature
Diurnal temperature variation is a meteorological term that relates to the variation in temperature that occurs from the highs of the day to the cool of nights.
Lifting process responsible for the choppy type of turbulence often encountered during flight within the lower 3000 feet of the troposphere
Mechanical turbulence
AWOS
Automated Weather Observation System
LWIS
Limited Weather Observation System
What is an RVA. Who can provide it? How long is it valid.
Runway Visibility Assessment
Who can do it? A qualified person CAR804. Instrument rated pilots in accordance with CAR 602.131
RVA is valid for 20 minutes after being established
How many regions are GFA’s prepared across the country
7
What is the coverage period of a GFA? (Hours)
Coverage period of 12 hours and an outlook for a further 12 hours
Amendments to area forecasts are known as:
AIRMETs
What are the intensities of icing when reporting a PIREP?
Trace, Light, Moderate, Severe
What are the two types of airborne icing and their characteristics:
Rime Ice: rough, milky, opaque ice formed by the instantaneous freezing of small supercooled water droplets
Clear Ice: Glossy, clear, or translucent ice formed by the relatively slow freezing of large supercooled water droplets
Upper level charts are prepared at what levels and corresponding mb
5000 ft - 850mb
10000 ft - 700mb
18000 ft - 500mb
34000ft - 250mb
What is an AIRMET?
A short-term weather advisory I tended primarily for aircraft in flight, to notify pilots of potentially hazardous weather conditions not described in the current GFA and not requiring a SIGMET
What are the criteria for issuing an AIRMET
1) IMC conditions (BKN or OVC at less than 1000ft AGL vis less than 3SM
2) freezing precipitation (not requiring a SIGMET)
3) moderate icing
4) moderate thunderstorms
5) thunderstorms (isolated as opposed to a line)
6) surface mean winds increases to 20kt or more or gusts to 30kt or more when no winds were originally forecasted.
7) difference between observed and forecasted wind direction is greater than 60 degrees
What is the validity of an AIRMET?
Valid upon receipt until it is updated or cancelled. Will be superseded by the issue of the next regular GFA
List the 3 types of turbulence
Light
Moderate
Severe
List the 3 words used to describe the frequency of turbulence
Occasional - less than 1/3 of the time
Intermittent - 1/3 to 2/3
Continuous - more than 2/3
What is the validity period of a TAF?
30 hours
Describe the difference of the proximity qualifier, vicinity(VC) from a METAR to a TAF
Metar - VC means elements observed within 5 mi, but not at the station.
TAF - VC means between 5 and 10 NM from the centre of the runway complex
True or False - AWOS cloud height sensors tend to over- read during precipitation events
False they will under read
What is the wind speed, direction and temperature?
9900+00
Wind light and variable , temperature 0
What is the wind speed, direction and temperature?
2523
250 true and 23 knots
What is the wind speed, direction and temperature?
791159
290 true ( 79-50=29) at 111kt (11+100= 111), temperature -59
What is the wind speed, direction and temperature?
859950
350 true (85-50=35) at 199kt or greater, temperature -50
Describe all sky conditions and their coverage (oktas) SKC FEW SCT BKN OVC CLR
SKC - no cloud FEW - 0 to 2/8 summation amount SCT - 3/8- 4/8 summation amount BKN - 5/8 to less than 8/8 sum OVC - 8/8 summation amount CLR - clear below 10,000
What is a Col?
A col is a neutral region between two highs and two lows. Very undependable weather
What is Coriolis Force
The air moving from a high pressure area to a low pressure area does not flow directly from one to the other. It is deflected to the right in the northern hemisphere by a force called the Coriolis force
What is Buys Ballats Law?
If you stand with your back to the wind, the low pressure area will be on your left side
What is Radiation Fog and characteristics?
Formed on clear nights with light winds. The ground cooks losing heat through radiation. The air in direct contact with the earths surface is cooled. If the air is moist and the temperature is lowered below the dew point, fog will form
- light winds
- clear skies
- abundance of condensation
What is advection fog and it’s characteristics?
Caused by the drifting of warm damp air over a colder land or sea surface. Occurs most frequently in coastal regions.
- moist air from a warm region
- cold water
What is upslope fog?
Is caused by the cooking if air due to expansion as it moves up a slope. A light upslope wind is necessary for its formation
Steam fog
Forms when cold air passes over a warm water surface. Evaporation of the water into the cold air occurs until the cold air becomes saturated
Ice fog
Forms in moist air during extremely cold calm conditions. The tiny ice crystals composing it are formed by sublimation and are often called ice needles.
What is sublimation?
Water vapour changes into ice crystals
What is condensation?
Water vapour changes into water droplets
