W03 Sky Condition

Question 1

Summations

Answer 1

-Sum of layer values at and below a given level-Traces disregarded (TR adds like a zero)-Overlapping portions will increase summation amount

Question 2

SKC

Answer 2

Sky clearNo cloud of layer present

Question 3

FEW

Answer 3

FewLess than 1/8 to 2/8 Summation amount

Question 4

SCT

Answer 4

Scattered3/8 to 4/8 summation amount

Question 5

BKN

Answer 5

Broken5/8 to less than 8/8 summation amount

Question 6

OVC

Answer 6

Overcast8/8 summation amount

Question 7

Interconnected layers

Answer 7

Clouds of vertical development that may build up to reach or penetrate upperlayers.

Question 8

How to estimate sky coverage

Answer 8

-Divide the sky in half-Estimate amount in each half(each half now contains 4/8)-Select the halves to suit prevailing conditions(Most of the clouds north, divide north and south)

Question 9

How to estimate sky coverage during darkness

Answer 9

-Stars plainly visible (no clouds or surface based layer) means clear sky-Dimming of stars means cloud present-Use appropriate tools (ceiling projector beam, ceilometer)-City or other lights can be very useful

Question 10

Predominant Cloud Type

Answer 10

2 or more types at same height = 1 layer-identified as predominant type by amount-TCU or CB always predominant type (regardless of amount)-TCU and CB Always included in column 30 (SCT020CB)-TCU and CB at same height, TCU treated as if it were CB

Question 11

Low Etage priority (Degree of Vertical development)

Answer 11

CB, TCU, CU(Highest to lowest)

Question 12

Middle Etage priority (Degree of Vertical development)

Answer 12

ACC

Question 13

High Etage priority (Degree of Vertical development)

Answer 13

CC (Considered a layer cloud)

Question 14

Column 26

Answer 14

Total amount-Less than 8 octas if any clear blue skies or bright stars-Traces entered as 0

Question 15

Column 30

Answer 15

Sky Condition-SKC, FEW, SCT, BKN, OVC-Layer altitude next to amount (expect for SKC) ex. FEW008

Question 16

Column 40

Answer 16

Cloud and/or Obscuring Phenomena (type and amount)-Clear sky (SKC) = no entry-appropriate cloud abbreviation and amount for each layer ex, SC5CI3-Trace is 1 ex. SF1CF1

Question 17

Obscured

Answer 17

A surface-based layer with a summation amount of 8/8 (constitutes a vertical visibility VV)

Question 18

Partially Obscured

Answer 18

A surface-based layer with a summation amount of at least 1/8 but less than 8/8 will be included in the amount of the first layer aloft.

Question 19

RA

Answer 19

Rain (any form including SHRA & FZRA)

Question 20

SHGR

Answer 20

Hail

Question 21

PL

Answer 21

Ice Pellets (including Ice Pellet Showers)

Question 22

DZ

Answer 22

Drizzle (Including Freezing Drizzle)

Question 23

IC

Answer 23

Ice Crystals

Question 24

SN

Answer 24

Snow (Snow Showers, Snow Pellets and Snow Grains)

Question 25

BLSN

Answer 25

Blowing Snow

Question 26

FG

Answer 26

Fog (any form)

Question 27

BLDU

Answer 27

Dust, Blowing Dust

Question 28

DS

Answer 28

Duststorm

Question 29

HZ

Answer 29

Haze

Question 30

BLSA

Answer 30

Sand, Blowing Sand

Question 31

SS

Answer 31

Sandstorm

Question 32

FU

Answer 32

Smoke

Question 33

VA

Answer 33

Volcanic Ash

Question 34

If you can see through a surface-based layer

Answer 34

It is the lowest layer

Question 35

If you Can’t see through a surface-based layer

Answer 35

Its the highest layer

Question 36

Vertical Visibility

Answer 36

The distance an observer on the ground can see vertically into a surface-based layer

Question 37

Rounding-off procedures for cloud height

Answer 37

-To nearest 100 feet (up to 10000 feet) -249 feet rounds to 200 feet -251 feet rounds to 300 feet-To nearest 1000 feet (starting at 10000 feet) -10501 feet rounds to 11000 feet -10499 feet rounds to 10000 feet-Exactly in between, choose the lower value -250 feet rounds to 200 feet

Question 38

Height of layers shall be determined to:

Answer 38

The nearest 100ft

Question 39

Reportable values for cloud heights and VV

Answer 39

-Up to 10000 feet - 0 100 200 .... 9800 9900 10000-Above 10000 feet - 10000 11000 12000 .... 39000 40000-If observed is exactly half-way between reportable values, choose lower value.

Question 40

Factors to consider when estimating cloud height

Answer 40

-Apparent size of the elements-Height of one layer relative to another-Known heights of hills, towers, etc.-Difference between temperature/dew point-Balloon enters side/break in cloud-Strong winds with the VV-Reflection of city lights

Question 41

Techniques for estimating layer heights

Answer 41

-Penetration: note visibility into the cloud-Variable: note average height over a short time-CU type: (Temperature - dew point) X 4= reportable value (lower limit) - doesn't apply near mountains, or if T

Question 42

Entries on Form 2322 for increments of 100 feet

Answer 42

Three digits-300 feet coded as 003-9400 feet coded as 094-11000 feet coded as 110

Question 43

Ceiling Definition

Answer 43

The ceiling is the lesser of:a) the height above ground of the base of the lowest layer aloft at which the summation amount exceeds half of the sky (more than 4/8)b) the vertical visibility into a surface-based layer which completely obscures the sky

Question 44

Variable Ceiling Definition

Answer 44

When the ceiling is 3000ft or less and observed to be "variable", i.e.., rising and falling from a mean value by 1/4 or more of the mean value, the range of variation shall be indication in remarks.

Question 45

Ceiling Determination

Answer 45

Layer aloft-Measured-Aircraft-Balloon-EstimatedAcronym M-A-Y-B-E

Question 46

Balloon Ceiling

Answer 46

Height determined by a ceiling balloonBased on rate of ascent (460 ft/min)

Question 47

When to use a ceiling balloon

Answer 47

If no ceilometer available, use balloon when ceiling ≤ 1000 feet

Question 48

Height the balloon starts to fade

Answer 48

Base of cloud

Question 49

Height balloon disappears

Answer 49

-Vertical Visibility (VV) for a surface-based layer-Penetration for a layer aloft

Question 50

Cautions when using a balloon

Answer 50

-Rain (unless very light) and wet snow, indicated height too low-Strong wind/poor visibility, indicated height too low-Break in layer, indicated height too high

Question 51

Name the 4 main parts to a balloon filler assembly

Answer 51

-Cylinder valve-Regulator valve-Needle valve-Rubber tubing

Question 52

When to use a ceiling projector

Answer 52

-If no ceilometer, use projector at night/just before daylight