Weather Flashcards
1
Q
METAR TYPES
A
Normal- scheduled observation taken at the end of each hour
SPECI- observation taken at an unscheduled time due to certain criteria like low visibility, low clouds, frozen precipitation or thunderstorms
2
Q
VC vs. DSNT on METAR
A
VC- METAR weather is reported within 5-10 NM of station
DSNT- weather is reported greater than 10 NM from station
3
Q
TAFs- Terminal Area Forecast
A
- Issued every 6 hours for a 24 or 30 hr period
- 5 SM from center of airport
4
Q
METAR reading- BCFG
A
Patches of fog
5
Q
METAR reading- BLSN
A
Blowing snow
6
Q
METAR reading- +TSRA
A
Thunderstorm with heavy rain
7
Q
METAR reading- VV003
A
Vertical visibility 300 ft
8
Q
METAR reading- R35L/5000
A
RVR for runway 35L is 5000’ as seen from cockpit
9
Q
METAR reading- 350V040
A
Winds are variable between 350 degrees and 040 degrees
10
Q
M01/M01
A
Temp is -1 degree and dew point is -1 degrees.
Meaning Fog (possibly freezing fog) low visibility is expected
11
Q
AO2
A
Automated observation with precipitation discrimination sensor.
AO1 cannot detect type of precipitation.
12
Q
B & E on METAR/TAF
A
Began & End
13
Q
BC
A
Patches
14
Q
BL
A
Blowing
15
Q
BR
A
Mist
16
Q
DR
A
Low Drifting
17
Q
DS
A
Dust Storms
18
Q
DU
A
Dust
19
Q
DZ
A
Drizzle
20
Q
FC and +FC
A
FC- Funnel Cloud
+FC- well developed funnel cloud like a tornado or waterspout
21
Q
FG
A
Fog
22
Q
FU
A
Smoke
23
Q
FZ
A
Freezing
24
Q
GR Hail
A
Greater than 5 mm in diameter
25
GS Small Hail/Snow Pellets
Less than 5 mm in diameter
26
HZ
Haze
27
IC
Ice Crystals
28
MI
Shallow
29
PL
Ice Pellets
30
PO
Well developed dust/sand whirls
31
PR
Partial
32
PY
Spray
33
RA
Rain
34
SA
Sand
35
SG
Snow Grains
36
SH
Showers
37
SN
Snow
38
SQ
Moderate squalls
39
SS
Sandstorm
40
TS
Thunderstorm
41
UP
Unknown Precipitation
42
VA
Volcanic Ash
43
VC
In the vicinity of
44
-
+
P
M
B
E
- Light
+ Heavy
P More than
M Less than
B Began
E Ended
45
BKN
Broken cloud layer 5/8ths to 7/8ths
46
CB
Cumulonimbus
47
CLR
Sky clear at or below 12,000 AGL
48
FEW
Few cloud layer 0/8ths to 2/8ths
49
OVC
Overcast cloud layer 8/8ths coverage
50
SCT
Scattered cloud layer 3/8ths to 4/8ths
51
SKC
Sky Clear
52
TCU
Towering Cumulus
53
AMD
Amended forecast
54
AUTO
Without human editing
55
BECMG
BECMG 0002 = becoming from 00 to 02 Zulu
56
CAVU
Ceiling and visibility unlimited
57
COR
Correction
58
DSNT
Distant weather
59
FM
From - FM 0200 = from 0200 Zulu the weather is reporting the following
60
FROPA
Frontal Passage
61
LTG
Lightning
62
LDG
Landing
63
M
Minus, below 0, less than
64
NO
Not Available
65
NSW
No significant weather
66
P6SM
Plus 6 SM, greater than or more than
67
PK WND
Peak Wind
68
PRESFR/PRESRR
Pressure falling or rising rapidly
69
PROB40
Probability of 40%
70
RVRNO
Runway visual range not available
71
SLP (SLP140)
Sea Level Pressure- add 10 to numbers given
Ex. SLP140 = 1014.0
1013.2 mb is std.
72
TEMPO
Temporary
TEMPO 0002 = temporarily 00 to 02 Zulu
73
T02560179
Temperature 25.6, Dew point 17.9
74
TWR VIS
Tower visibility
75
V
Varying
76
VV
Vertical visibility, indefinite ceiling
77
WS
Wind Shear
78
WSHFT
Wind Shift
79
With an altimeter setting of 29.85, what is the lowest usable flight level?
FL185, per 91.121 (b) chart (see 91.121 altimeter settings page)
80
Stages of a Thunderstorm
1. Cumulus- updrafts
2. Mature- rain, updrafts/downdrafts, wind shear, hail, turbulence
3. Dissipating- all downdrafts
81
What is needed for a thunderstorm to form?
1. Unstable atmosphere - warm column of air rising faster than the std. lapse rate, continuing the raising
2. Lifting action- fronts, terrain, thermals
3. Moisture
82
Where does most of weather occur?
Troposphere
83
What causes weather?
Temperature- Unequal heating of earths atmosphere
Warm air- less dense- allows for more movement
Cold air- more dense- more stable
84
What stage of a TS would you most likely encounter an anvil top?
Mature stage- Anvil top extends out in front of the direction of the storm. Hail is a possibility below/around an Anvil
85
If the Anvil top is pointed left, what way is the TS moving? Which way would you try to fly around the storm? How many NM?
1. Moving in direction of Anvil (Left)
2. Fly upwind at least 20NM
86
What are the effects and indications of Virga?
1. Virga is precipitation falling that evaporates before reaching the ground.
2. An indication of downdrafts/microbursts beneath and around the surface. Why? Evaporative cooling- when rain evaporates it cools the air—> colder air/heavier/more dense air slams into the ground
87
Types of Fog
1. Radiation
2. Advection
3. Upslope
4. Freezing
5. Precipitation-Induced
6. Steam
7. Valley
8. Ice
88
Radiation Fog
Calm air, cool nights. Ground cools faster than overlying air, cooling air to its dew point.
89
Advection Fog
Coast/Horizontal winds. Warm moist air blows over cooler dry land, cooling air to its dew point.
Ex. San Francisco
90
Upslope Fog
Forms adiabatically. Moist air blows up a slope, cooling to its dew point as it raises.
91
Precipitation-Induced Fog
Rain falling through cold air evaporates, evaporative cooling leads to saturation.
92
Steam Fog
Ex. Lakes in cooler seasons
Calm dry air over warmer water conducts temperature. Air becomes moist and then cools quicker than the water to its dew point.
93
Freezing Fog
Air temps at or below freezing. Moisture in the air freezes and becomes visible.
94
Valley Fog
Moist soil from previous precipitation. Air becomes moist then cools to dew point.
95
Ice Fog
Mostly occurs at polar regions or areas of extreme low temps.
96
What is the significance of the temperature/dewpoint spread?
A temperature/dewpoint spread that equals or close together means the air is nearly 100% saturated.
Ex. Clouds, fog, mist, low visibility
97
Describe a microburst
A microburst is a powerful downdraft of a column of air (associated with thunderstorms). Once that downdraft reaches the ground, it spreads out in all directions causing a wind change as you fly through. Hazardous to aircraft landing and taking off.
98
What are the aircraft indications of a microburst?
When flying into a microburst with a headwind- IAS & Climb increases. Once through the headwind, it switches to a tailwind- IAS & Lift decrease causing a stall quickly and low to the ground.
99
How do you escape a microburst?
Continue straight ahead, max power, Vx climb, monitor airspeed and avoid stalling
100
What is wind shear?
An abrupt change in wind speed or direction. Can cause turbulence or loss of control.
101
When can you accumulate ice?
When there is visible moisture and temps are near or below freezing.
102
What are the different types of ice?
1. Clear
2. Rime
3. Mixed
103
Clear Ice
Glossy, clear ice formed by slow freezing of super cooled water as it flows over the wings.
- forms between 2 and -10 degrees Celsius
104
Rime Ice
Rough, milky, opaque ice that instantly freezes. Very rapid freezing of super cooled droplets as they strike the wing.
- Low temps, lesser amounts of liquid water, low velocities, and small droplets form rime ice.
105
Mixed Ice
Mixed is a combination of clear and rime ice on the same surface.
106
Induction Icing
Forms around the air inlet of turbine engines and can damage compressor blades.
107
Structural Icing
Forms on an aircraft’s lift generating surfaces, disrupts smooth airflow, decreases lift and increases drag
108
What temperature difference between dew point and air temp would result in fog?
5 degrees or less between the two
109
What does ICE do to a wing?
Changes the shape of the wing, causing airflow to become disrupted.
-Decreases lift and increases drag.
110
When does FROST occur?
Frost will occur when the collecting surface temperature is at or below the dew point of the air and the dew point is below freezing.
111
What weather is associated with a COLD front and WARM front?
Cold- forms when cooler air displaces warmer air from below, forcing the warm air to rise. — cumuliform clouds, heavy showers, fast moving, thunderstorms. (LOW pressure system)
Warm- forms when a moist, warm air mass slides up and over a cold air mass. — stratiform clouds, low visibility, widespread rain. Can bring gentle rain or light snow, followed by warmer/mild weather. (HIGH pressure system)
112
‼️‼️ How are Lenticular clouds formed?
“Ocean Waves” above a mountain top- Winds at the top of a cloud layer are moving faster than the layer below.
-They form when moisture is being transported over the top of a mountain in a stable layer of atmosphere.
-Indicative of turbulence and wind shear
113
In standard atmosphere, what is the speed of sound?
741.4 MPH
114
Thunderstorms should be avoided by how many miles?
20 miles
115
How long is a TAF valid for? How many times/day is it released?
24 or 30 hrs
Released 4 times a day. 00z, 06z, 12z, 18z
116
When is filing an alternate required? What weather must your alternate have?
1-2-3 rule: 1 hr before or after ETA, WX must be 2000 ft ceilings and 3 SM visibility. If not, then an alternate is required.
Alternate must have weather (800/2) for non-precision & (600/2) for precision.
117
What risks are associated with Thunderstorms and how do you avoid them?
Microbursts and hail.
118
How long can a microburst last for and how many miles can they take up?
Around 15 min from the time it strikes the ground until dissipation.
Horizontal winds continue to increase during the first 5 min with max winds lasting 2-4 min in a 2.5 mile radius.
119
On a TAF if there is a TEMPO line what weather does it resort back to after tempo is over?
The main line before the tempo.
120
What fronts are associated with a microburst?
Cold front
121
Can you overfly a thunderstorm?
Never plan to. But yes, suggested 1000ft for every 10 kts of movement.
122
TEMPO- what does it mean to us?
TEMPO change in wx, expected to last less than an hour at any given time.
Occurs during a total or less than half the time period of the TAF.
123
What is a mountain wave?
Oscillations of wind perpendicular to the ridge of the mountain. Can cause loss of altitude, airspeed fluctuations and turbulence.
