Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MET > Facts > Flashcards

Facts Flashcards

1
Q

What types of cloud are tornadoes associated with?

A

Cb (mature stage of TS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What time of year are tornadoes most likely to occur in North America?

A

Spring and early Summer as cold polar air is moving over a rapidly warming land mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Diameters of a typical tornado?

A

tens or hundreds of metres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the lifespan of a tornado?

A

up to thirty minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the lifespan of the mature stage of thunderstorm?

A

up to an hour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the speed of movement of a tornado?

A

30mph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the name for a tornado over the sea?

A

A watersprout

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the name for a tornado over the sea?

A

A watersprout

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do tornados move?

A

With the TS they are associated with

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Typical windspeed inside a tornado?

A

300mph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What kind of pressure at the centre of a tornado?

A

Very low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is an area typically associated with Tornados?

A

central plains of the USA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a funnel cloud?

A

A tornado type cloud that does not reach the ground.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What conditions trigger tornados?

A

Very large Cb clouds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is required for very large Cb?

A

moist, unstable air and convective lifting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a watersprout?

A

similar to a tornado but takes place over the sea and does not reach the same intensity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the name of the Cold Air Outbreak in Australia?

A

Southerly Buster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the name of the Cold Air Outbreak in South Africa?

A

South Westerlies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the name of the Cold Air Outbreak in South America

A

Pamperos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the name given to Cold Air Outbreaks in the NH?

A

Generic name of Cold Air Outbreaks!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When does the ITCZ pass over the equator?

A

Spring and Autumn equinoxes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When are the spring and autumn equinoxes?

A

March and September

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

When are the long rains?

A

April (the spring equinox)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When are the short rains?

A

October (the autumn equinox)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where does RVR appear?

A

Only in METAR, it is not forecast.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the size of drizzle

A

Between 0.2mm and 1mm diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are ice pellets?

A

precipitation which leaves the clouds as liquid (i.e. rain or drizzle) and freezes as it falls through a cold layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the difference between ice pellets and hail?

A

Ice pellets are formed outside of the cloud while hail is formed inside the cloud.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Size of raindtrops

A

1mm to 5.8mm (bigger drops would break up)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How is hail formed?

A

Ice Crystal at the top of the cloud falls and gathers moisture as it does so.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which cloud is Hail associated with?

A

Only Cb..

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Where will the largest hailstones be found?

A

In Cb over continental interiors rather than over the sea because the convective and orographic triggers will be stronger over the land than sea.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the consequence of a very high freezing level (16,000ft) in equatorial regions?

A

Hail will melt before it reaches the ground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Highest level of encountering hail?

A

Up to 45,000ft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How long is the dissipating stage of a Thunderstorm?

A

about 2 hours typically.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Why is the anvil created?

A

Upper winds spread the ice crystals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Formula for PGF/Isobar spacing?

A

PGF = 2wVp Sin ( Lat )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What causes a halo around the sun or moon?

A

Refraction of light passing through ice crystals of cirrostratus on a warm front.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is a blocking anticyclone?

A

A WARM quasi-stationary anticyclone that has broken away from the Azores high can disrupt the passage of the travelling lows over the North Atlantic and their associated fronts. The influence of warm highs extends into the upper troposphere these stable features will affect the sub tropical jetstream often changing its direction to flow north/south for thousands of miles. Can lead to heat waves in summer and long periods of cold weather in winter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the temperature of a blocking anti-cyclone?

A

WARM!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What type of cloud does drizzle come from?

A

Stratus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

In general is visibility greater in rainfall or drizzle?

A

Greater in rain as small water droplets in drizzle indicate very little lifting action but greater size raindrops indicate more lifting action and unstable air. Unstable air clears pollution vertically so visibility is better

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Where does coalescence produce only very light rain or drizzle?

A

Mid-latitudes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the most northerly latitude of the ITCZ in July over Africa?

A

15°N

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the final northerly position of the ITCZ in July in China?

A

30° - 35°N

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

When are there more warm occlusions?

A

WINTER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

When are there more cold occlusions?

A

SUMMER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Where is the sub-tropical high pressure belt located?

A

Centred around 30°N / 30°S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Formula for Tailwind or Headwind?

A

Cos (angle) X Speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Formula for hPA decrease with altitude?

A

96 * (Temperature (°K) / Pressure (hPa))

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Formula for RH

A

100 - 5 (Temperature - Dew Point)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are the locations of the 0° isotherm?

A

Poles = Ground level
Temperate Latitudes = Ground to 10,000ft
Tropics = 10,000ft - 16,000 ft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What are the locations of the -45° isotherm?

A

Arctic - 18,000ft over India

Equator - 37,000ft (Jan) - 40,000ft (July)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

How do you convert between Kts and Km/h

A

1.85

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the visibility for fog?

A

< 1000m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the visibility for mist?

A

1000 - 5000m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the amounts that the surface wind will differ to the free flow wind?

A

Over land, 30° and 50%

Over sea, 10° and 70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What are the amounts that the surface wind will differ to the free flow wind?

A

Over land, 30° and 50%

Over sea, 10° and 70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the cause of convergence around a low?

A

Surface friction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the cause of divergence around a high?

A

Surface friction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What happens to he pressure change across 100m as you go up in the atmosphere?

A

As you go higher up there is less change in pressure per 100m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What happens to he pressure change across 100m as you go up in the atmosphere?

A

As you go higher up there is less change in pressure per 100m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What wind speeds are typically quoted for radiation fog?

A

2 - 8 kts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What winds are are typically quoted for advection fog?

A

15 Kts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Formula for Density?

A

Density = Pressure / Temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What is the average height of the tropopause?

A

11km

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is the height of the tropopause in ISA

A

11 KM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the average atmosphere condition?

A

Conditional instability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is the average atmosphere condition?

A

Conditional instability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

How do we find the actual ELR?

A

Use of a raido sonde.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What does the wet bulb, dry bulb spread tell you?

A

About the humidity of the air

It indicates RH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What is the hair hygrometer used for ?

A

To measure humidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Where does the wet bulb temperature lie?

A

Between the dew point and the OAT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is a psychrometer?

A

A wet bulb and dry bulb thermometer together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What is the SVP over ice compared to supercooled water?

A

SVP less over ICE than over supercooled water at the same temperature

76
Q

What does SVP depend on?

A

TEMPERATURE & SURFACE

77
Q

What conditions do we expect to find the middle of a warm sector?

A

Tropical Maritime
low stratus, poor visibility, drizzle
In summer the cloud may lift and disperse but in winter the cloud base would remain low over the land

78
Q

What conditions are likely for the formation of mist/fog?

A

Temperature & dew point close together

79
Q

What is the Mediterranean climate?

A

Hot dry summers and cold wet winters

80
Q

When does freezing fog exist?

A

if the fog droplets are supercooled.

81
Q

Where do we find the squall line?

A

Ahead of a cold front

82
Q

What is a squall line?

A

A line of Cb associated with an advancing active cold front

83
Q

What is a squall?

A

An increase in wind strength lasting for several minutes.

Describes the increased wind produced by the gust front which precedes a TS

84
Q

What will happen when flying into freezing or supercooled rain?

A

Clear ice will form

85
Q

The pressure group in a METAR message represents what?

A

The QNH rounded DOWN

86
Q

What are the relative speeds of the cold and warm fronts?

A

The warm front moves at about 2/3 speed of the cold front

87
Q

What is the primary use of satellites?

A

to locate FRONTS in areas with few observation stations

88
Q

What is the difference between Ns and Cb precipitation?

A

Ns will give continuous precipitation whereas Cb will give showers

89
Q

What is the issue with heavy precipitation immediately ahead of an airbourne radar?

A

It may hide precipitation further away

90
Q

What might we find in the warm sector in the Summery months?

A

Fair weather Cu

91
Q

What does AIRMET apply to?

A

Low level operations only

Below FL100 or FL150 in mountainous areas

92
Q

What is MWO?

A

Meteorological Watch Office

93
Q

What is a MO

A

A Meteorological office

94
Q

What does a WMO issue?

A

AIRMETs and SIGMETs

95
Q

What does a MO issue?

A

Aerodrome forecasts and briefing documents

96
Q

What is VOLMET?

A

HF and UHF

METAR & TAF

97
Q

How is Temperature and Dew point rounded in METAR?

A

Rounded UP Up Up

** Careful of rounding negative figures **

98
Q

How is sustained windspeed measured?

A

average of 10 minutes

99
Q

Tropical Storm windspped?

A

> 33 Kts

100
Q

Cyclone/Hurricane/Typhoon windspeed?

A

> 63 Kts

101
Q

Relationship between cloud bases and wet/dry bulb temperatures?

A

the further away the wet bulb and dry bulb temperatures the higher the cloud base will be.

102
Q

What happens to windspeed at latitude increases?

A

Decreases

103
Q

Consequences of sinking air?

A

Dissipate cloud and trap pollution, giving poor visibility

104
Q

Where do the trade winds blow from?

A

Sub Tropical Highs

105
Q

What kind of fog might you get on either side of a warm front?

A

frontal fog ahead

advection fog behind

106
Q

What is a cold air pool?

A

very cold upper air and warm surface air

107
Q

What does a stormscope detect?

A

Electrical discharges

108
Q

Mean temperature in polar climates?

A

+10

109
Q

What is the typical latitude of the prevailing westerlies?

A

40° - 60°

110
Q

Where does a microburst occur?

A

Under a TS

111
Q

What causes frontal fog?

A

high relative humidity

112
Q

What is a consequence of frontal fog

A

reduction in visibility

113
Q

What is mixed ice?

A

mixture of rime ice and clear ice

114
Q

Where is rime ice typically found?

A

In Ns

115
Q

What weather is associated with a stationary high pressure region over land in the winter?

A

High pressure is associated with stable, sinking air. Without convective or frontal lifting there will be little or no cloud and precipitation. Any cloud formation in winter will be stratus rather than cumulus and the precipitation will be drizzle (or granular snow) rather than rain (or snow).

116
Q

What is a stable layer at some height in the low troposphere of an older high at mid-latitudes?

A

A subsidence inversion

117
Q

Which clouds can produce large water droplets?

A

large Cu which will contain both water droplets and ice crystals

118
Q

What can occur over land in a col in summer?

A

Air Mass Thunderstorms
Lack of turbulence –> surface heating –> convective activity
Isolated, Thermally generated CBs across the area

119
Q

What can occur in a col in winder over land?

A

Radiation fog

120
Q

What are the typical col conditions?

A

light winds, clear skies, inversion at low level

121
Q

What are the ATIS wind direction?

A

Magnetic

122
Q

What will a sea breeze do in the NH?

A

Veer and increase in strength by the afternoon

123
Q

What is the minimum Jet Stream speed?

A

60 kts

124
Q

What does adiabatic mean?

A

heat does not enter or leave the system

125
Q

How long does TEMPO last for ?

A

no more than one hour on any one occasion and the total time spent in those conditions will not add up to more than half the period

126
Q

When will gusts be reported in a metar?

A

when the gust is at least 10 Kts more than the wind

127
Q

METAR validity

A

only at time of observatoin

128
Q

What does a SNOWTAM include?

A

information abut breaking and runway surface contamination

129
Q

Where does breaking information occur?

A

in the supplementary info in ATIS & METAR

130
Q

Where do the feathers on the wind arrow point?

A

towards the low pressure

131
Q

What is a polar low?

A

small short lived depression that can bring frequent heavy wintery showers esp costal areas

132
Q

Where does the sun set?

A

In the west in both hemispheres

133
Q

PIREP

A

SPECIAL Air report

134
Q

AIREP

A

Routine Air report

135
Q

Polar ice cap is the source of which kind of air?

A

Arctic

136
Q

When does a thermal low form?

A

Strong surface heating

137
Q

Can a thermal low form over land?

A

Yes

138
Q

Can a thermal low form over sea?

A

Yes

139
Q

Can a polar low form over the land?

A

No

140
Q

Can a polar low form over the sea?

A

Yes

141
Q

Where does a polar low normally form?

A

the the arctic Maritime airmass over the North Atlantic Ocean

142
Q

When does Rime ice form?

A

less that -7°C in Stratus and less that -23°C in Cumulus

143
Q

When is there no risk of icing?

A

less than -45°C

144
Q

When does hoar frost form?

A

when the airframe is at a temperature below 0°C and it climbs into warmer, moister air there will be direct sublimation => HOAR FROST

145
Q

How does hoar frost form

A

Water vapour turns directly into water droplets on the aircraft surface: Sublimation

146
Q

How much should you avoid a Cb by?

A

5000ft and 10NM normally

147
Q

what are the air masses that are observed most frequently over Europe?

A

maritime Tropical and maritime Polar

148
Q

How often does the airfield windshear alert system update?

A

every minute

149
Q

Where do easterly waves form?

A

Close to ITCZ

5° - 20° N/S

150
Q

What weather is associated with an easterly wave?

A

Severe weather;

A line of Cb and TS aligned N - S from TRAILING EASTERLY EDGE

151
Q

What is a line of active Cb know as?

A

A tropical tornado

152
Q

What percentage of easterly waves turn into TRS?

A

1/10

153
Q

What is an easterly wave described as?

A

A ripple in the isobars which are otherwise parallel to the ITCZ

154
Q

What kind of pressure is associated with an easterly wave?

A

a trough of low pressure

155
Q

Where is the polar front jet stream speed greatest?

A

Between a trough and a ridge

Strongest wind will occur where you have the greatest difference in temperature and pressure

156
Q

How much should you avoid a TS by at FL300

A

20NM

157
Q

What is rain ice?

A

a form of very heavy clear icing encountered when aircraft are flying the rain ice triangle

158
Q

How server is the rain ice?

A

Very; rain is just supercooled before hitting the aircraft, giving the worst possible clear ice with a high rate of accretion

159
Q

What is the visibility in a heavy dust storm?

A

< 500m

160
Q

What causes a sea breeze to veery?

A

As the breeze develops, the Coriolis force causes it to veer

161
Q

Where are blocking anticyclones located typically?

A

between 50°N and 70°N

162
Q

What wind do the isobars indicate?

A

the free flow wind, the surface wind will back compared to this

163
Q

What does the advection of warm air aloft indicate?

A
  • indicates the approach of a warm or cold occlusion

- both in NH and SH

164
Q

When can lightning appear in a thunderstorm?

A

Mature stage

165
Q

What causes lightning?

A

Build up of electrical potential in the cloud; upper cloud collects a positive charge while the lower cloud collects a negative charge - at a critical level this discharges as lightning.

166
Q

What does a doppler radar do?

A

Record the movement of raindrops so do show turbulence in cloud

167
Q

What can be expected around areas of convergence and divergence associated with a low?

A

Turbulence, Convergence results in cloud but divergence does not likely to be CAT over the divergence area

168
Q

When can advection fog be formed?

A

Day OR Night

169
Q

Visibility in blowing snow?

A

Whiteout, down to virtually zero

170
Q

What are the characteristics of stable air?

A

Poor visibility and stratiform cloud

171
Q

DALR close to SALR

A

just below tropopause where cirrus is found

172
Q

Where is mixed ice normally found?

A

Ns

173
Q

What is the vertical structure of the atmosphere?

A
174
Q

What is the Tropopause height at different latitudes?

A
175
Q

What are the DALR, SALR and ELR?

A
176
Q

What is the Harmattan?

A

Dry, dusty, NE wind from the Sahara [ITCZ RETREAT]

177
Q

What is the Haboob?

A

Sand storm associated with TS in Sudan

178
Q

What is an example of a Foehn wind?

A

Chinook, [ Canadian Prairies]

179
Q

What is the Mistral?

A

Northerly, from France, blowing from RHONE VALLEY, and past FRENCH ALPS. Valley wind with Katabatic enhancement (winter)

180
Q

What favours the formation of the Sirocco?

A

Low pressure area in the Med.

181
Q

What are the characteristics of the Sirocco, Ghibli and Khansin?

A

Dry, dusty, stabe. Blow out of the WINTER high pressure area over the Sahara in N Africa. Cause gradient wind dust storms from Algeria to Egypt. Sirocco may reach across Med to Europe bringing low stratus, advection fog and drizzle

182
Q

What is the Bora?

A

Cold northerly, pure katabatic wind [ALPS]
Funnelled into river valleys
blows down mountains
comes out at Adriatic over Trieste

183
Q

Are cold air pools more prevalent over land or sea?

A

Land

184
Q

How long does a cold air pool usually last?

A

for the life of the system they are sitting above

185
Q

diameter and lifespan of typical microburst ?

A

4km and 1.5 minutes

MET (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions