Met Random Stuff I Can’t Remember Flashcards
1
Q
Temperature Error Correction (TEC) =
A
TEC = 4 x ISA Dev. x (Layer or air/1000)
2
Q
Relative Humidity =
A
Relative humidity = 100 - (( Temp. - Dew point) x 5)
3
Q
Density Altitude =
A
DA = PA + 120 x ISA Dev.
4
Q
Temperature at tropopause poles and equator is?
A
Poles: -45
Equator: -75
5
Q
Pressure lapse rate is?
A
100hpa - 53,000ft 200hpa - 38,000ft 300hpa - 30,000ft 500hpa - 18,000ft 700hpa - 10,000ft 1013hpa - sea level
6
Q
Density lapse rate is?
A
- 302 - 40,000ft
- 609 - 22,000ft
- 903 - 10,000ft
- 225 - sea level
Density in kg/m^3
7
Q
Pressure systems in January are?
A
Icelandic low North Australian low Canadian high Azores high Siberian high
8
Q
Pressure systems in July are?
A
North American low
Asian low
Pacific high
Azores high
9
Q
Polar air mixing ratio is?
A
< 1g/kg
10
Q
Tropical air mixing ratio is?
A
28 g/kg
11
Q
Cloud droplet size is around?
A
0.02 mm
12
Q
Cloud levels are?
A
High: 16,500ft - 45,000ft
Medium: 6,500ft - 23,000ft
Low: Surface - 6,500ft
13
Q
Drizzle size is?
A
Less than 0.5 mm
14
Q
Rain size is?
A
More than 0.5mm
15
Q
Snow grain size is?
A
Less than 1 mm
16
Q
Snow pellet size is?
A
2 - 2.5 mm
17
Q
Small hail size is?
A
Less than 5 mm
18
Q
Hail size is?
A
Greater than 5 mm
19
Q
Continuous precip is?
A
60 mins or more from As or Ns
20
Q
Intermittent precip is?
A
Continuous with breaks As or Sc
21
Q
Showers are?
A
Short outbreaks Cu or Cb
22
Q
Waterdroplet auze is?
A
0.02 mm
23
Q
Microbust diameter is?
A
4 km
24
Q
How long does a microburst last?
A
1 - 5 min
25
Where and when do tornadoes occur?
Mid-west USA in spring/summer
26
Tornado windspeeds are?
100 - 200 kts in funnel
27
Tornado ground soeed is?
20 - 40 kts
28
Average tornado diameter is?
100 - 150 m
29
Tornadoes last up to?
30 mins
30
Thunderstorms require?
Moisture, instability and lifting force
31
Gust fronts occur when?
Mature stage and roll clouds
32
Fog vis
Less than 1000m
33
Mist vis
More than 1000m
34
Haze vis is up to?
5000m
35
Expexted vis of high level cloud is?
1000m +
36
Expexted vis of mid level cloud is?
20 - 1000m
37
Expexted vis of low level cloud is?
10 - 30m
38
Vis in METAR is in m up to?
In m up to 5000m then in km
39
Dust storm has what vis?
Less than 200m
40
How is vis reported? (What steps)
50m steps to up 800m
100m steps between 800 - 5000m
1km steps between 5000m - 10km
41
Harmattan reduces vertical vis?
3000 ft
42
Harmattan reduces horizontal vis?
200m
43
RVR when vis is?
Less than 1500m
44
What device measures vis?
Transmissometer
45
RVR reading updated every?
60s
46
RVR reading averages over how many mins for METAR and SPECI?
Averaged over 10 mins
47
RVR reported in what steps?
25m steps to 400m
50m steps between 400 - 800m
100m steps above 800m
48
Vertical vis reported to what alt?
2000ft
49
Vertical bis reported in what steps and units?
30m to 600m
Or
100ft to 2000ft
50
Calm wind is?
Less than 1kt
51
Gust is?
Increase in 10kt for less than 1 min
52
Squall is?
Gusts lasting more than 1 min
53
Gale force is?
34 - 47kt
54
Storm force is?
48 - 63kt
55
Hurricane force is?
+64 kt
56
Coriolis increases with?
Lattitude and windspeed
57
METAR wind is?
Degrres true and averaged over 10 mins
58
ATC wind is?
Magnetic and averaged over 2 mins
59
In the northern hemisphere coriolis deflectsvthe wind?
Right
60
Geostrophic wind afftected by?
Windspeed
Increases with lattitude
61
Friction layer deprh is affected by?
Terrain, windspred and stability
62
Going into the friction layer, in the N hemisphere the wind does what over land and sea?
Land:
Speed reduces by 50% and backs by 30 degrees
Sea:
Speed reduces by 25% and backs by 15 degrees
63
Foehn wind in Rocky mountains is called?
Chinook
64
Anabatic winds blow upslope during the?
Day
65
Anabatic winds blow downslope during the?
Night
66
Easterly jet
East to west
FL500
10 - 20 degrees
Only in Summer in N Hem
67
Sub-tropical jet
FL400
| 30 - 40 degrees
68
Polar front jet
FL300
| 50 - 60 degrees
69
Arctic jet
Only in winter
FL200
50 - 70 degrees
70
Jet stream dimensions?
2 miles deep
200 miles wide
2000 miles long
71
Min jet stream speed is?
60kt
72
Min jet stream speed on SIGWX chart is?
80kt
73
Change bars // indicate?
Change of 20kts or 3000ft
74
How far can turbulence extend after mountain waves?
50 - 100 nm downwind
All the way up to the lower Stratosphere
75
Mountain waves require wind speeds of?
15 - 20 kts
76
Rockies turbulence can extend
300 nm downwind
77
Low level wind shear system updates every?
60s
78
Polar Maritime
```
Cold, moist
Instable
Cb
Rain showers
Good vis
```
79
Arctic maritime
Very cold
Unstable
Cu, Cb
Rain or snow showers
80
Polar continental
From Russia
```
Stable
Clear skies
Low temps
Frost
Possible snow showers if moisture picked up over the sea
```
81
Tropical continental
```
Stable
Clear skies
High temps
Haze
Can get TS in Summer
```
82
Tropical maritime
```
Stable
Low stratus
Advection fog
Dz
Poor vis
```
83
Returning polar maritime
```
Stable
Low stratus
Dz
Occasionally Cu, Cb in Summer
Morning BR
```
84
Weather extenda how far ahead of a warm front?
500 - 700nm
85
Steepness of a warm front?
1:150
86
Steepness of cold front?
1:80
87
Warm front travels at?
2/3 of speed of cold front
88
With a warm occlusion where is the coldeat air?
Ahead of the front
89
TRS need?
```
Unstable air
Sea temp. min 26.5 degrees
Deep oceans 200-300 ft
Trigger
Coriolis 5 - 25N
```
90
Tropical depression windspeeds are?
20 - 33kts
91
Tripucal storm windspeeds are?
34 - 63kts
92
Cyclone windspeeds are?
More than 64kts
93
TRS groundspeed is?
15 - 20kts
94
TRS eye diameter is?
20 - 50km
95
Average diameter of a TRS is?
500 km
96
How long does a tempo last
Up to 1 hour
97
Bergeron is?
Ice crystal precip formation process
98
Coalescance is?
Water droplet formation process
99
Diameter of TRS mature stage
500km
