WX Flashcards
What are the 5 different types of FOG?
Radiation, Advection, UPSLOPE, STEAM, ICE
Describe Radiation FOG?
Calm, clear nights in low lying areas (mountain valleys generally) the ground cools from TERRESTRIAL COOLING until due point is reached. Fog without Wind
Which type of fog (generally) is associated with GROUND FOG?
Ground fog is typically Radiation Fog that is 20 feet of less thick.
Describe Advection FOG?
Moist air passes over a cool surface, common on warm front passing over a significant snow pack. Fog with wind.
Describe Upslope FOG?
Moist, stable air blown upslope of mountain.
Describe Steam FOG?
Cold, Dry Air over warm water, associated with the coldest day of the year generally. Low level turbulence and icing associated.
Describe Ice FOG?
EXTREME COLD (-25F), water vapor forming ice crystals.
What are the 3 stages of a Thunderstorm?
Cumulus, Mature, Dissipating
What stage of a TSTM typically reveals an ANVIL?
Mature stage
What stage of a TSTM typically contains the greatest level of up and down drafts?
Mature stage
What stage of a TSTM typically the heaviest rain?
Dissipating stage
What stage of a TSTM typically produces WIND/SHEAR and MICRO BURST?
Mature stage
What distance must we remain clear of TSTMs?
10 miles / 3 miles for TakeOFF and Landings
What are the CLOUD Ceilings classifications
Broken, Overcast, Obscured (haze or fog)
What are the 4 different cloud types?
Stratus, Altostratus, Cirrus and Cumulus
What are the 4 different FRONTS?
Cold, Warm, Stationary, Occluded
Describe a COLD FRONT?
Faster moving front (generally passing in a few hours), pushes warm air up like a snow plows snow…violent cumulus and turbulent
Describe a WARM FRONT?
Slow moving (generally over 2-3 days), air moves up and over cooler air eventually mixing and increasing area temperatures. Stratus clouds, more stable air, with lower visibility
Describe a STATIONARY FRONT?
2 air masses of relatively equal strength combine…combination of both cold and warm fronts.
Describe a OCCLUDED FRONT?
Cold front over taking a warm front.
What atmospheric factor causes rapid movement of surface fronts?
Upper winds blowing across the front
What weather difference is found on each side of a dry line?
Dew point difference, a dew point front or dry line is formed when two air masses of similar density and temperature meet
What term describes an elongated area of low pressure?
A trough is an elongated area of low flow pressure
Where is the normal location of the jet stream relative to surface lows and fronts?
The jet stream is normally located north of the surface systems
What type of icing is associated with the smallest size of water droplet similar to that found in low level stratus clouds?
Rime ice forms when drops are small such as those in level stratus clouds
What condition is necessary for the formations of structural icing in flight?
Flying thru visible moisture and the temperature where the water strikes the aircraft must be freezing
What condition is indicated when ice pellets are encountered during flight?
Freezing rain at higher levels
When will frost most likely form on aircraft surfaces?
When both the temperature and dew point are below freezing. Occurs on clear nights with little or no winds
What temperature conditions are indicated if precipitation in the form of wet snow occurs during flight?
The temperature is above freezing at flight level
What type of precipitation is an indication that super cooled water is present?
Freezing rain at flight level
Radiation fog occurs when there is a surface based temperature inversion.
WHAT characterizes a ground based inversion?
Poor VIS
What condition produces the most frequent type of ground or surface based temperature inversion?
Terrestrial radiation on a clear, calm night
What causes advection fog to form?
Warm moist air flowing over colder surfaces
What causes upslope fog to form?
Moist, stable air moving over higher ground, cooling adiabatically
What minimum thickness of cloud layer is indicated if precipitation is reported as light or greater intensity?
More than 4000 feet thick
Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?
Cumulus clouds begin to elongate and tower (because of up and down drafts)
Which weather phenomenon signals the end of the mature stage of a thunderstorm?
ANVIL is forms and rain begins
What is and where do squall lines most often develop?
Ahead of a cold front in moist unstable air
Which types storms are most likely to produce funnel clouds or tornadoes?
Steady state (frontal) thunderstorms
You are observing cumulonimbus mamma clouds.
What inference can be made to this sighting?
Violent thunderstorms, turbulence, lightning, low level wind shear, potential micro burst and tornadoes.
Where is the greatest area of thunderstorm turbulence?
Under the anvil
What is a definition of a wind shear?
Rapid airspeed changes of more than 15 knots, rapid vertical speed changes of more than 500ft/min
Which wind shear condition results in an increase in ground speed?
Tailwind shearing to a headwind
Which wind shear condition results in an increase in indicated airspeed?
Headwind shearing to a tailwind
Where can the maximum hazard zone caused by wind shear associated with a thunderstorm be found?
All sides and directly under the center
What are the greatest threats to heavy rain during landing?
Reduced visibility and hydroplaning on the runway
What is a necessary condition for the occurrence of a low-level temperature inversion wind shear?
A calm or light wind near the surface and a stronger wind above the inversion, 2000 to 4000ft winds 25kts or more
Which type of clouds may be associated with the jet stream?
Cirri-form clouds
One of the tools used in recognizing severe weather is the convective outlook. What information is provided?
Describes activities for the following 24 hours
If squall lines are reported at the destination airport, what wind conditions exist?
Sudden increase of winds, 15 to 20kts for one minute
When flying over the top of severe thunderstorm the cloud should be overflown by how many feet?
Clear the top by 1000ft for each 10kts of wind
What is the maximum amount of area coverage, by thunderstorms, at which the entire area should be circumnavigated?
6/10 th
At what altitude of cloud tops should a thunderstorm be considered extremely hazardous?
Tops above 35,000ft
If you can see under the thunderstorm, is it ok to fly under?
No, turbulence and wind shear could be disastrous
What is the first rule of wind shear escape?
Avoid
Once wind shear has been encountered what is the accepted recovery?
Increase power, increase pitch, maintain configuration
One way to improve flight crew’s ability to recognize and respond quickly to a wind shear encounter is to;
Develop strong CRM
When encountering a wind shear on the runway with insufficient runway to stop or accelerate to a normal speed, what procedure should the pilot use?
Rotate early and except a lower airspeed and higher pitch attitudes
What separation is recommended from any thunderstorm?
20 miles 40 miles to fly between
What adjustments to cockpit lighting should be made when in the vicinity of TSTMs?
Turn up lighting to max
What techniques may be used for airborne radar?
Tilt antenna up and down to scan for other activities
Upon entering a thunderstorm, what type of course should the pilot take?
Set straight course through the storm
Upon entering a thunderstorm, and encountering strong up and down drafts what specific precaution should a pilot take?
Make sure to maintain wings level during altitude changes
What action is recommended when encountering turbulence due to a wind shift associated with a sharp pressure trough?
Establish a straight course through
What action is recommended if turbulence is encountered with a direct headwind or direct tailwind?
Change altitude (winds elongate and make areas long and shallow)
What is the difference between occasional, intermittent and continuous chop?
Occasional 1/3, Intermittent 1/3 to 2/3, Continuous Chop is more than 2/3
What are the alternate airport IFR weather minimums?
For an airport that has at least one approach procedure, adding 400’ to the authorized CAT 1 DH/DA and 1sm to the CAT I visibility landing minimum.
For an airport that has at least two approaches to two different suitable runways, adding 200’ to the authorized CAT I DH/DA and a visibility adding 1/2sm to the higher of the CAT I landing minimum of the two approaches.
