Temperatur Abnahme ISA conditions
-0,65 Grad / 100m
-2 Grad / 1000ft
Abnahme ft pro hPa
27 ft/hPa
altitude Tropopause
11km (rghly 36.000ft)
altitude Stratopause
50km
Bedeutung QFE
current air pressure at an airfield
Bedeutung QFF
QFE reduced to sea level using the current temperature
Veränderung Wind Boden (angle & speed)
sea surface
land surface
sea surfaces:
10 degrees friction angle, 70% of original wind speed
land surfaces
30 degress friciton angle, 50% of original wind speed
min wind speed for classification as a jetstream
60kt
AIREP
AIREP (special) are to be provied as soon as practiable after encountering a Significant Meteorological Informaiton (SIGMET) phenomenon or any other MET condition which is likely to affect the safety, or efficency of other aircraft.
SIGMET phenomenon are:
severe turbulence
severe icing
severe mountain wavs
…
how to calculate the cloud base / condensation level?
Cloud base = (surface temperature - surface dew point) * 400
sea smoke / steam fog
immer warmes wasser
warm water, cold air
das Wasser ist heßß und raucht deswegen
wie kochendes Wasser
surface inversion must be in place or else th air would start rising
evaporated vapour froma warm water surface condenss on contact with a much colder air and is uanble to rise bcause of a surface inversion
Hail METAR
GR
Hail
frozen precipitation and the diameter of hailstones are larger than 5mm
GS: small hail or ice pellets
Passage of a warmfront
Wind: veers sharply, windspeed decreases slightly
temperature: sudden rise
pressure: stops falling
Dew point: sudden rise
cloud: 8/8 base very low, NS, ST
Precipitation: moderate or heavy continous
visbility: very poor, fog can occur
The four major type of air masses
Arctic
Polar
Tropic
Equator
subsidence inversion
Air sinks and warms adiabatecally
at some point it might be warmer than the air below —> subisdence inversion
—> can occur within a warm core high pressure system
Themal low
Boden Tiefdruck
Oben hochdruck
Luftsäule warm thermal
Cold anticyclone
Anticyclone: Hochdurckgebiet am Boden
Cold: kalt
kalter boden -> luft sinkt ab -> Hochdruck am Boden, Tiefdruck oben
Isobaren zsm da kalt
-> über kaltem gebiet
-> tendency to sustain itself
Polar Low
only open seas
formed only over water
Polar Front -> differential haeting of the ground
prevailing initial instability
-> developes over open seas during the cold season in polar or arctic air masses.
-> triggered by an outbreak of colad arctic air
-> unstable thermal stratification causes deep convection, which warms the core with latent heat and enhances the advection process
nur in polar gebieten
Warm anticyclone
-> Gegenstück zum frontal low
anticyclone -> hoher Druck am Boden
excess air mass aloft -> converges aloft and subsidces
-> warms because of subsidence -> air diverges on the bottom -> High pressure
air warm, which enforces the pressure pattern
-> tends to broaden the upper level ridge, consequently the contour lines and also the jet streams will surround the high in the shape of a Q
-> entstehen durch upper air movements
Frontal low / Frontal depression
low pressure system that contains different air masses and fronts
3 - 5 days
Gegenstück warm anticyclone
Frontal low
typisches Hoch bzw Tiefruckgebiet das durch Luftmassen aloft hervorgerufen wurde
Gegenstück thermal low
-> mainly formed over land
cold anticyclone
Tropical Revolving storm
Menge
Why Human People Buy Jeans WHPBJ
5 6 9 12 20
West of Darwin 5
Hurricanes 6
Phillipines/East Darwin 9
Bengal: 12
Japan: 20
mainly in the summer and autumn
Bewegung ITCZ
Wasser
Land
viel stärkere Verschiebung über Land als über Wasser über die Jahreszeiten
Januar: berührt gerade noch das horn von Afrika, grob 0grad; Ort der ITCZ 0-7 grad N
zentral Afrika -> deutlich südlich des Äquators
-> also known as doldrum
Cold Air Pool
low pressure system aloft
Spaltet sich aber von den Luftmassen und jet streams ab, die wollen nicht so um so enge Kurven fließen.
Da oben deutlich kältere Luft -> instability -> convection -> TS/RA immer dieses Wetter
rather stationary
a low pressure area with cold air compard to its surrounding. only in upper contour charts
500hpa
ceilometer
measuring device for the ceiling
VC im METAR
in the vicinity of the airport 8 bis 16km
> special weather phenomena
mechanical turbulence / frictional turbulence
occurs within the friction layer (2000-3000ft)
> depends on:
the strength of the surface wind
the nature of the surface
the stability of the air (the more usntable -> the greater the turbulence)
strongest close to the ground
geostrophic force =
coriolis force
strongest at the poles?
adiabatisch
kein Austausch an Wärme
Hagel
frozen precipitation > 5mm
sonst ice pellets PL
latitude subtropical high pressure belt
25 - 35 degrees
bzw 20 -40
Hardley cell -> closer to the equator
Ferrel cell -> closer to the poles
clouds with large supercooled water droplets
CU and CBs
NS
Freezing Rain
concentration of water droplets is highest in convective clouds
temperature dictates what amount and size of water droplets can be found in a cloud
aerodrome warning
for a/c on the ground
who produces a SIGMET
metrological watch office
symbols for significant weather
definition
ISOL
OCNL
FREQ
ISOL : up to 50%
OCNK: 50-75% well separated
Freq > 75%
height of lines of equal pressure on a surface cahrt
lines of equal pressure reduced to sea level
Calculation of Relative Humidity
Relative Humidity = 100 - 5* spead
Td = T - (100-RH) / 5
nach T minus suchen
Temperatur abnahme
saturated
unsaturated
saturated: 0,6/100m ; 1,8 / 1000ft
unsaturated: 1/100m; 3 / 1000ft
Towering Cumulus synonym
Cumulus congestus
cloud from which drizzle falls
stratus
coalescence effect
raindops collide and form bigger raindrop
in the mid latitudes this process produces only drizzle or very light rain
warm front after front weather
stable air, stratified clouds, drizzle, light rain and mist
warm front what to do
planning: shortest way through
flight: orbit and wait for it to pass
average diameter tropical revolving storm
500km whole storm
diameter of the eye: 10-20 NM
Diameter of the whole storm: 270NM
westerly waves
polar fronts
avoiding thunderstorms and CBs
CB 10 NM
TS 20NM
2010
RVR visibility
RVR is generally more than visibility
P enis größer als gedacht
U up besser
D down
when visibility is below 1500m
in meteres or feet
Flight levels - pressure
FL50 = 850 hPa
FL100 = 700 hPa
FL140 = 600 hPa
FL180 = 500 hPa
FL240 = 400 hPa
FL300 = 300 hPa
FL340 = 250 hPa
FL390 = 200 hPa
FL450 = 150 hPa
Define Ice Water Content of a cloud
the IWC is measured in g/m3 and it reaches maxium values in the upper levels of the core of convective systems+
clouds where only ice particles are present (cirrus??)
in areas of extreme convective activities
Turbulence clouds
formed in stable air conditions, where the vertical movement of the air is limited.
cold air over land
Harmattan
a northeasterly wind flowing out from a high pressure over sahara which brings a lot of haze to cities in northwest africa
dust and poor visibility
AIRMET
information issued by a meteorological watch office
concerning:
the occurence or expected occurence of specified en route weather phenomena
may affect the safety of low level aircraft ops
was not already included in the forecast issued for the low level flights in the flight informaiton region concerned
AIRMET low level
SIGMET high level
METAR
SQ
Squalls lasting more than a minute often several minutes
wind direction
indicated by the tip of the arrow
What is the average width of the precipitation zone of a cold front?
…warm front
50 - 100NM
cold front average slope
1:80
tornado
average speed of movement
20 to 40 kts
What are the rainy seasons in equatorial Africa?
March to May
October to November
Definition of ice water content
ice mass per unit volume of air
height of CB clouds at the equator
50.000
When do cold occlusions occur most frequently in Europe?
in summer
freezing fog
means supercooled water droplets
atmospheric density is expected to be 50% of the density at MSL in ISA at
22.000ft
north atlantic area north of 60degr in winter -> mean height of the tropospause appr
29.000ft
dry adiabatic lapse rate
most linear decrease of temp with alt
speed warm front
10 knots
tropical revolving storm -> tropical cyclone
tropical revolving storm: windspeeds lower than 63
pecentage of air consisting of water vapour
0-5%
GS
soft hail / graupel
solid precipitation transparent/translucent diameter of less than 5mm formed by freezing raindrops >
comes from convective clouds, such as CB etc.
smaller than hail under 5mm
snow falls and collides with supercooled water droplets -> causing hypride particle that freeze, forming small opaque balls.
GS => soft hail / graupl
ice pellets
mountain waves max alt
FL600
drizzle droplet diameter
less than 0.5mm
diameter sand grain and wind speed for decreasing vis
0.08mm and 20kt
tornadoes speed
apprx. at around 20kts movement
funnel with a speed of appr. 200kt
secondary depression hängt sich an die…
cold front
vertical visiblity reported in
100ft steps up to 2000ft
30m steps up to 600m
atis surface winds
metar
atis: last 2 min
metar: last 10min
average
air pressure development polar front
ahead of the warm front: steady decrease
at the warm front: stops falling
in the warm sector: steady and drops with the arrival of the cold front
at the cold front: starts to rise
behind the cold front: increases slowly
duration of the cumulus stage (building stage) of a TS
15-20min
what is correct about frontla fog
occurs in a narrow band where the frontal surface meets the ground
radioation fog
nachts und morgens
a blocking high can be col or warm
zwei striche jet stream achse
entweder rapid Höhenänderung >3000ft
velocity change >20kts
pressure in surface charT
QFF
most severe icing hazards in
CU
freezing rain nur wenn oben wärmer und dann wieder in kältere luftschicht
perpendicular to the direciton of movment of the front
parallel
no icing unter dem freezing level
frontal fog
tropical zero degrees isotherm
16.000ft
state of runway section metar
extend of contamination
depth of deposit
friciton coefficient
runway designator
when on final approach below a microburst
changes of pitch attitude
position fronts
mean position polar front
summer: 50-65: new foudnland scotland
winter: Florida / southern part of England
satellite images
use always both
icing zone ITCZ
FL 160 - 260
drifiting snow vs blowing snow
drifting snow: weniger als 2m höhe über dem Boden
blowing snow: mehr als 2m
stationary fronts
cloud band of varying intensity
precipitation clouds great vertical extent containing ice crystals and water droplets
hail
storng updrafts and downdrafts in these clouds
severe precipitaion in form of shower and rain
haze and landing
sun directly ahead: reduciton of visiblity because sun reflects from the haze layer
sun neben an: angeblich more than 1500m
air masses von wo
tropical continental deutlich südlciher
mature stage TS
cold occlusions most frequent in
summer
weather phenomeon Special METAR
volcanic ash cloud
temperature tropopause to FL600
remains constant
cold occlusion / warm occlusion erkennen
snow grain
fall from stratus or supercooled fog
cloud type freezing rain
Bergeson findeisen process
occurs in miexed clouds with supercooled water and ice
Coalescence:
collision of two or more droplets to merge
crucial in the formation of rain
when droplet too large -> rain
-> Bergeson relevant in mixed clouds!!!!!!
-> Coalescence here only responsible for drizzle / light rain
cold / warm occlusion
tropical rain climate typical characteristics
RH 80%
freezing level: 15000ft
average temp: 28
a depression over western europe
has formed 4 days before over the western atlantic
Blick anticyclone in the northern hemisphere is a
A quasi stationary, warm anticyclone, situated between 50 and 70 N
Speed of a warm front
10kt
Which cloud produces drizzle
Stratiform clouds
Precipitation from clouds with water and ice crystals
Light candelas
Always 1000
Slope cold front
1 - 80
Icing strati form clouds
Typical 0- -15 grad moderate
At lower temperatures rather unlikely
Last changed2 years ago