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Flashcards in Weather Deck (46)
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0
Q

Standard temp at sea level. Lapse rate?

A

15C

2C/1000 feet

1
Q

Jet stream

A

Winds > 50 knots; in the troposhere; moves south/increases velocity in winter (IRTP 1-4)

2
Q

Air circulation in Northern Hemisphere around high press system:

A

clockwise around high pressure

3
Q

Coriolis force

A

right angle to wind; deflects wind to the right in North Hem

4
Q

Unstable vs stable air

A

Unstable: cumuliform clouds, showery, turbulence, clear
Stable: stratiform clouds, continuous precip, smooth, poor vis

un=CSTC (unstable cats see thru clouds)

5
Q

Cloud types

A

high clouds: cirrus, cirrocumulus, cirrostratus - ice crystals
unstable: cumulus
prefix “nimbus” means raincloud
lenticular clouds: lens shaped, near mountians, very turbulent

6
Q

Three stages of thunderstorm development?

A

cumulus (updrafts)
mature (rain)
dissipating (downdrafts)

7
Q

Most hazardous types of thunderstorm (2)?

A

1) Squall-line thunderstorms; develop ahead of cold front

2) Embedded thunderstorms

8
Q

What to do if you enter a thunderstorm?

A

Eyes on instruments, reduce power, ride the waves, don’t turnback

9
Q

Conditions for ice formation?

Aerodynamic cooling?

A

Visual moisture and temp < 0C

Can lower temp in airfoil even if temp is >0

10
Q

Types of icing?

A

Rime: small droplets immediately freeze on surface, forms on leading edges, milky appearance (from air bubbles), most common, associated with stratus/smooth air

Clear: from larger droplets or freezing rain, most dangerous, hard to see, very rapid, very rare

Mixed: characteristics of both

11
Q

Two other types of icing?

A

Structural: ice on exterior, occurs when supercooled water contacts any part of aircraft < freezing
Induction: “affects powerplant operation”

12
Q

What to do if rain is freezing on impact?

A

Fly higher

13
Q
Other considerations with icing:
takeoff
a/c certified for ice
tail
power
A

No takeoff if any ice on aircraft
“roll upset” - severe inflight icing (for planes certd into icing)
tail can collect faster, cause stall, especially when flaps are applied
more power required

14
Q

ice the thickness of sandpaper

A

can cause 30% loss of lift, 40% more drag

15
Q

Wind shear
definition
expect when (3)?
where is it around cold/warm fronts?

A

change in wind speed or direction
1) strong temp inversion, 2) around TS, (3) near frontal activity
in front of warm, behind cold

16
Q

TAF & METAR issuing time format

A

METER date/zulu eg. 091955Z: date=9, zulu=1955
TAF issue/valid time eg. 091730Z 0918/1024
issued on the 9th at 1730Z, valid from 18Z on the 9th, to 24Z on the 10th

17
Q

layer thickness math from METAR?
if airport elev=1300, metar says BKN008, OVC020?
tops are reported 3800

A

OVC is 2000+FE = 3300 feet

and 500 feet thick

18
Q

TAF Qualifiers
cloud amount
FM interpret

A

FEW > SCT > BKN > OVC (FSBO)

FM091930: beginning of change, eg day=09, zulu=1930

19
Q

METAR remark

RAE42SNB42

A

rain ended at 42 min past the hour, snow begin at 42 past the hour

20
Q

TAF distance and duration

A

5 mile radius, valid for 24 hours, issued 4 times/day

21
Q

Area forecast (FA)
size
issuance

A

several states

3x per day

22
Q

PIREP format

A

UA/OV OKC 063064/TM 1522/FL080/TP C172/TA M04/WV 245040/TB LGT/RM IN CLR

over OKC 63deg rad, 64 miles, at 1522Z, 8000 feet, cessna, temp=-4C, wind from 245deg at 40knots, turb is light

23
Q

Winds aloft decode?

A

direction, velocity and temp (if >50 knots, then -50 +100; “99” >200)
eg 234502: from 230 true north, 45 knots, temp=2C
eg 734502: from 230 true north, 145knots, temp=2C
eg 739902: from 230, >200 knots, temp=2C

24
Q

Weather advisories types, freq, max forecast period?

A

AIRMETS and SIGMENTS, unscheduled and issued when reqd. Issued at 30 intervals, may live for 6 hours

AIRMETS -haz weather that may affect single engine
SIGMENT - all planes
CONVECTIVE SIG - tornadoes, TS, embedded, sev ice, turb

25
Q

Convective Outlook

A

Used to plan flights later in the day. Predicts TS in the next 24H

26
Q

Radar summary chart

A
Shows only ppt.  
Only chart that shows size and intensity of TS
rating:
solid: instense, extreme
one ring: strong
two rings: weak or mod
27
Q

Constant Press Chart

A

Upper air weather shows temp, press, dp, wind, over 12 H period

28
Q

Sig Weather Prog Chart

A

shows surface & 24,000 feet at 12 & 24 out

29
Q

What procedures should you use to land if icing suspected?

A

more power, higher airspeed, flapless

expect higher stall, longer roll

30
Q

Microburst

A
  • rapid downdraft from cloud down to the ground where it spreads in directions (think flushing tiolet)
  • dissipates after 10-20 min
31
Q

Thunderstorm - inadvertent penetration

A

low as possilbe
tighten seatbelts
pitot heat, lights on
slow to man speed
do not turn around (load factor too high)
do not attempt to hold altitude (ride it out)

32
Q

Icing details (from Everything Explained)

A
temp +5 to -20C
check AIRMET, SIGMETS
"slight possibility" = KNOWN icing
stay 3000 below or 8000 above freezing level
climbing is the first rule for icing (to air too cold for icing); descend is the second option
90% of ice in 3000 feet layer
most clouds max at 30,000
land with fast airspeed, no flaps
33
Q

Freezing rain

A
indicates warmer air above
most severe, very fast appearance
forms on sharp surfaces
very fast buildup
turn around
seen close to the ground
34
Q

TAF

issued

A

Terminal Aerodrome Forecast
24 hour forecast issued 4x/day
issued at 32 large airports for a 5 mile radius

eg KPIT 091730Z 0918/1024 …..FM091030
day = 9th, 1730Z
valid time = day 09, 18Z to the 10 at 24Z
beginning at day 09, at 10:30Z

35
Q

TAF abbreviations
VC
- “nothing” or +

A

VC - vicinity
- light, nothing=moderate, + heavy
SH=showers, DZ=drizzle, BL=blowing, FZ=freezing, BC=patches, MI=shallow, PR= partial, DR=drifting

RA=rain, GR=hail, SN=snow, PL=ice pellets, SG=snow grains, IC=ice crystals, GS=small hail, UP=unknown ppt

BR=mist, FU=smoke, VA=volcanic ash, SQ=squall, DS=dust storm, SS=sand storm, PO=sand whirls, FC=funnel cloud, +FC=tornado

36
Q

EFAS

Enroute flight advisory service

A

122.0

37
Q

AIRMET
zulu
tango
sierra

A
Wx of interest to all aircraft, especially small
4x per day for a 6 hour forecast
zulu - icing and freezing levels
tango - turbulance, strong wing
sierra - mountain obscuration or IMC
38
Q

SIGMET

A

Significant met info

serious Wx include turbulance, icing, smoke, ash

39
Q

Five types of NOTAMS

A

(D) NOTAM: (distant); common type, airport info
(FDC) NOTAM: (Flight Data Center); regulatory, eg TFR
AC: Advisory circular
Pointer :military
GPS: must ask if getting briefing

40
Q

Ice pellets indicate?

A

Freezing rain above, do not climb

41
Q

Three phases of TS?

A

Cumulus: water vapor condenses
Muture: when rain hits the ground
Dissipating: characterized by downdrafts/lightening

42
Q

Five forecasts types

A
Area forecast
Winds aloft
Wx depiction - shows IFR conditions
Radar summary - rain and direction
Prog chart - 12/24 hours
43
Q

Ceiling & vis catagories

A

LIFR 3000 >5

44
Q

+ and - on meters, eg -SHRA

A
  • –> light

+ –> heavy

45
Q

types of fog?

A

radiation (ground): Ground cools air. warm, moist air; cool, calm nights, little wind
advection (sea): Wind pushes warm air over water or gound
upslope: moist air in low dew point conditions

Acro: RAU