Meteorology

Question 1

SIGWX chart validity

Answer 1

3 hours each side of validity time

Question 2

SPECI

Answer 2

Aviation Special Weather

Question 3

TAF

Answer 3

Aerodrome forecast - issued every 6 hours

Question 4

METAR

Answer 4

Aviation routine weather report
hourly or half hourly when conditions are at or above specified levels - SPECI = special observations when below specified criteria or significant changes since previous report

Question 5

SIGMET

Answer 5

Info concerning enroute weather phenomena which may affect safety of aircraft operations

Question 6

Overshoot Shear

Answer 6

Wind occurrence produces INITIAL effect of overshooting the desire approach path / and or increasing airspeed

Question 7

Undershoot Shear

Answer 7

INITIAL effect undershooting desired approach path and or decreasing airspeed

Question 8

SIGWX Pennants and Feathers Values

1. Pennant
2. Feather
3. Half feather

Answer 8

1. 50
2. 10
3. 5

Question 9

Forecast abbreviations
SKC
FEW
SCT
BKN
OVC
NSC and CAVOK

Answer 9

SKC Sky clear
FEW 1-2 oktas 
SCT 3-4
BKN 5-7
OVC 8
NSC and CAVOK: NIL Significant cloud

Question 10

Windshear intensity:
light
moderate 
strong 
severe

Answer 10

light - minor excursions
moderate - significant effect on control
strong - difficulty keeping flight path or airspeed
severe - hazardous effects to controllability

Question 11

CAVOK (3)

Answer 11

1. Vis greater 10k
2. Nil sig cloud below 5000 or highest 25nm MSA - no CB or TCU
3. Nil sig wx

*elements of vis, weather, and cloud will NOT be given when CAVOK reported

Question 12

FM period

Answer 12

The term FM is used when one set of prevailing weather conditions is expected to
rapidly change to a different set of prevailing weather conditions. The indicator is the
beginning of a self-contained forecast, with the new conditions applying until the end
period of the forecast or until the commencement time of another FM or BECMG
group.

Question 13

BCMG period

Answer 13

The term BECMG is used when one set of prevailing weather conditions is expected
to change, during the given period, to a different set of prevailing weather conditions.
The indicator is the beginning of a self-contained forecast, with the new conditions
applying until the end period of the forecast, or until the commencement time of
another BECMG or FM group.

Question 14

Wind - TAF

Answer 14

The wind direction is given in degrees True, rounded to the nearest 10 degrees. A
variable wind direction is given as VRB (used when the forecasting of a mean wind
direction is not possible).
The wind speed is given in knots (KT).
The maximum wind gust is included, after the letter G, if it is expected to exceed the
mean by 10 knots or more, e.g. 28020G30KT gives a wind direction of 280° True, with
a mean speed of 20 knots, and a maximum gust of 30 knots.

Question 15

Visibility - TAF

Answer 15

The horizontal visibility is given in metres in increments of 50 metres when visibility is
forecast to be less than 800 metres; in increments of 100 metres when forecast to be
800 metres or more but less than 5,000 metres; and in increments of 1,000 metres
when forecast to be 5,000 or more but less than 10,000 metres. Visibility is always
given in a four figure group: e.g. 500 metres is given as 0500. Forecast visibilities
of 10 kilometres or more are given as 9999. Visibility is not given when CAVOK is
forecast.

Question 16

TEMPO and INTER

Answer 16

The terms TEMPO and INTER are used to indicate significant temporary or
intermittent variations from the prevailing conditions previously given in the TAF.
TEMPO is used for periods of 30 minutes or more but less than 60 minutes. INTER is
used for periods less than 30 minutes.

Question 17

PROB

Answer 17

The term PROB is used in a TAF if the estimated probability of occurrence is 30 or
40% (probabilities of less than 30% are not given), and is only used with reference to
thunderstorms or poor visibility (less than the alternate minimum) resulting from fog,
mist, dust, smoke or sand. If the estimated probability of occurrence is equal to or
greater than 50%, then reference to PROB is not included.

Question 18

TURBULENCE - TAF

Answer 18

Special reference is made in TAF to hazardous turbulence, other than that associated
with CB and TCU, that may endanger aircraft or adversely affect their safe or efficient
operation.

Question 19

SIGWX parallell lines

Answer 19

A

20 knot change is indicated by two parallel lines across the jet stream ( ).

Question 20

SIGWX - tropopause

Answer 20

The tropopause is indicated at various points by a rectangular box framing the flight
level of the tropopause. The location of the highest and lowest tropopause points may
also be shown.

Question 21

PNR

Answer 21

point of no return The last possible geographic point at which an aircraft can proceed to an
available en route alternate aerodrome for a given flight. It is the point beyond
which diversion to the en route alternate aerodrome is no longer possible and
the PIC is committed to proceeding to the destination aerodrome.