Weather Flashcards
General features of a low in N hemisphere
- Wind direction CC relative to center
- lower pressure than surroundings
- rising air with dry&wet adiabatic cooling
- clouds form
- bad weather (precip)
Pressure Systems at
- 60N
- Equator
- North Pole
- 30N
- low
- low
- high
- high
Prevailing wind direction between
A. Equator and 30N
B. 30N and 60N
C. 60N and North Pole
A. NE
B. SW
C. NE
Which cloud type
A. In unstable maritime polar airflow
B. In stable maritime tropical airflow
A. Cumulus
B. Stratus
Define warm/cold front
Warm: Leading edge of a warm air mass. Warm air replaces cold air
Cold: vice versa
Cloud type & precip until warm front passes
Stratiform & continuous precip
VIS, ceiling, air pressure before warm front
Sinking VIS, ceiling and air pressure
Turbulence, icing and temp change at warm front
Light turbulence, rime ice, increasing temp
Conditions at warm front with exceptional unstable conditions
Cumulus embedded in stratus, showers
Where is the warm sector in a low and which air mass contacts the ground there?
Between warm & cold front, warm air mass contacts ground
Which amount of clouds, precip and VIS in warm sector?
Broken clouds, temp precip, moderate VIS
Type of stability for cold front
A. Type I
B. Type II
A. Unstable
B. Stable
Turbulence, temp change and pressure change at cold front type I
Moderate - severe turbulence, sinking temp, rising pressure
Clouds, VIS, phenomena and icing at Cold front type I
Cu, TCU, CB; low VIS in precip, else good; clear ice; showers, thunderstorms, hail
Clouds, VIS, phenomena and icing in cold front type II
NS, AS; low VIS; mixed&rime; continuous precip
Name of the area behind cold front
Precip, cloud type, icing, turbulence and VIS
Rear side
ISOL showers, cumuliform, clear ice, moderate turbulence, outside precip great VIS
Explain the formation of an occlusion
Cold front catches up with warm front, warm air mass is lifted off the ground
Weather conditions at occlusion
Warm & cold front conditions, very bad and severe weather
Where do you expect a squall line?
In front of/parallel to a cold front, in the warm sector
Cloud type, phenomena and wind at squall line
CB, Cu, TCU; showers, hail, TS, gusty wind
Sequence of cold front, rear side, warm front, warm sector
Warm front, warm sector, cold front, rear side
A unstable & decreasing temp
B unstable & decreasing temp
C no temp change
D increasing temp
E stable
Moderate icing
Thrust, lift, drag, weight
Thrust decrease
Lift decrease
Drag increase
Weight increase
Effect of icing on
A. Rotors & engine
B. Moveable parts
A. Vibration and damage
B. Makes them stuck
Temp range of icing in clouds
0C to -20C
Within which kind of clouds do you expect severe icing?
Young TCU, cumuli at a front, CB, upsloping clouds at windward side of a mountain
Which type of ice
A. Cu at -5C
B. TCU at -15C
C. AS at -11C
D. FZRA
E. NS at -25C
A. Clear
B. Rime
C. Rime
D. Clear
E. None
Which type of ice
A. CB at -8C
B. AC at -15C
C. CS at -30C
D. +FZDZ
E. NS at -5C
A. Clear
B. Rime
C. None
D. Clear
E. Rime
Explain frost
Ice crystals formed by sublimation
Clouds at 8,000‘ with precip. Temp near surface is negative, between 1,000‘ and 2,000‘ positive air temp.
Which hazard can be expected during final?
FZRA
Temp near surface is -4C, aloft overcast AS with rain
Hazard near surface?
FZRA
d
What is necessary for the formation of a TS?
Lifting action, unstable atmosphere, high humidity
TSRA and obscured sky. Which cloud?
CB
Where do
A. Air mass TS occur
B. Frontal TS occur
A. Isolated within air mass
B. Long fronts
Which type of air mass TS is caused by
A. Thermal lifting/ converging airflow
B. Me mechanical lifting over mountains
A. Convective TS
B. Orographic TS
8 TS hazards
- lightning
- hail
- gusts
- severe turbulence & icing
- rapid reduction of VIS & ceiling
- Altimeter/ radar/ radio errors
Sunny June day, moist and unstable atmosphere.
Hazard developing in afternoon?
Convective TS
Moist and unstable airflow.
Hazard over Black Forest?
Orographic TS
When penetrating a TS, in which level greatest risk of
A. Icing
B. Lightning strikes
A. Between freezing level and -10C
B. Freezing level +- 5,000‘
Why is hail a hazard?
Damage, low VIS, danger to ground operations
In which cloud is hail likely?
CB
What is the cause of
A. Convective turbulence
B. Mechanical turbulence
A. Heating from below
B. Obstructions, strong wind near the ground
High air temp on final approach
Which hazard?
Convective turbulence
Wind 250/20G34
Hazard on low level flight?
Mechanical turbulence
Hazard during strong airflow over Harz mountains
Mountain wave
Over Alps 190/80G102
Where severe turbulence?
Above and North of the Alps
Side of mountain where mountain waves can be expected and which hazard
Leeward side
Severe turbulence
What is wind shear, where does it occur and which hazard?
Sudden difference in wind direction or speed
In fronts or inversions
Causes turbulence
Crossing cold front below clouds, no hail and no TS
Which phenomenon is likely?
Wind shear
What and where is a microburst?
Sudden downdraft below/in the vicinity of a TS
Circumstances to submit PIREP
- Weather is considerably different than forecasted
- Unusual weather phenomena
- Missed approach due to weather
Define isobars
Lines connecting places of equal pressure
A. 220/moderate to strong, stratiform, continuous precip
B. Fine day and night, risk of radiation fog forming in the night
How long is the forecast period?
ETD - ETA+1h
Two parts required in weather brief
Written and oral form
Void after
Time until T/O had to be executed, else forecast is invalid, max 3h(+2h extension) prior to T/O
Under which circumstances are sunrise/set times in the route forecast?
T/O or landing is planned +-1h around Sunrise/set
Difference between solid and dotted lines in area weather
Solid: border between different prevailing conditions
Dotted: border between different minimal conditions
A. Hills > 2,000‘ MSL obscured
B. Valleys < 2,000 MSL locally obscured
Meteorological factors effecting night illumination
Clouds, precip, ground conditions
Define civil twilight
Time after sunset/ before sunrise when the sun is 6deg below the horizon
When is ˋdark nightˋ
Sun is at least 16deg below the horizon
Explain moon brightness
Brightness of the horizontal ground caused by moonlight
Limiting NVG range
1,5 km
Effect of snowfall on NVG
Strong deterioration
Effects of dense mist on NVG
Strong deportation
A. 19 mlx
B. 70 mlx
C. 200 mlx
