Converting FORM 500 Series to LMR

(Form Types 500, 511, 522, 523, 524, 525, 533, 555, 556)

No. Field Element	Description Procedure

No.

==============================================================================

RPTIN

RPTID

1 B10	10-deg box	Compute based on Lat/Long; translate to LMR

2 YR 800	year	Translate to LMR

3 MO 696	month Convert local to GMT; translate to LMR

4 DY 695	day Convert local to GMT; translate to LMR

/808	FT 555 &556-GMT day of the month (01-31);
translate to LMR

5 HR 693	hour Check local ship time against GMT for	/690 (local ship time)	accuracy; translate to LMR

6 TI	time indic. Set to 0; nearest whole hour (GMT)

7 LON 551 longitude Convert from Octant, Longitude to LMR
/649 (octant)	convention (0-359.99 degrees East)

751/802 Exceptions for forms 555 & 556 where the

longitude is in degree & minutes; hemisphere

is reported as E or W except when an estimated	position Then: E = D; W = V: convert to LMR	convention (0-359.99 degrees east). If
estimated position set LI (lat/long indic.)

= 3 (interpolated position)

8 LAT 550 latitude Convert from Octant, Latitude to LMR

convention (-90.00 to 90.00; 90 south to 90	north)

750/801 Exceptions for forms 555 & 556 where the

latitude is in degree & minutes; hemisphere

is reported as N or S except when an estimated	position Then: N = M; S = R: convert to LMR	convention (-90.00 to 90.00; 90 south to 90	north). If estimated position set LI (lat/long	indic.) = 3 (interpolated position)

9 LI	lat/lon indic. Set to 0; if degrees and tenths

(reported position)

Set to 3; if position estimated or
interpolated

Set to 4; if degrees and minutes

(reported position)

10 DCK	deck Set deck to 700; 1912-1946 U.S Merchant Marine

11 SID	source ID Set ID = 84 or 85; (NCDC keyed data)

84 = QC'd data

85 = non-QC'd data

12 PT	platform type Set to 5; ship

13 QI	quality indic. Left blank; assign as missing

14 DS	dup status Left blank; assign as missing

15 DC	dup check Left blank; assign as missing

16 TC	track check Left blank; assign as missing

17 PB	pressure bias Left blank; assign as missing

Note: need to design a consistency check to	to compare pressure corrected (inches)

against barometer as coded (millibars)

18 DI	wind dir. indic. Set to 1; 32 point compass

19 D 612	wind direction Code according to table 8, LMR documentation

20 WI	wind speed indic. Set to 5; Beaufort force

21 W 711	wind speed Convert to tenths of meters per second
according to Table K5-5, page K29 COADS Release 1, Reference Manual

22 VI	vis. indic. Set to 0; estimated

23 VV 610	visibility Add 90 to the coded value (see table below)

Visibility code	Description	Conversion code

(form)	(LMR code)

0	Object not visible at 50 yards	90

1	Object not visible at 200 yards	91

2	Object not visible at 500 yards	92

3	Object not visible at 1/2 nautical	mile	93

4	Object not visible at 1 nautical mile	94

5	Object not visible at 2 nautical miles	95

6	Object not visible at 5 nautical miles	96

7	Object not visible at 10 nautical miles	97

8	Object not visible at 30 nautical miles	98

9	Object visible at > than 30 nautical miles	99

Note: There are slight differences between the

descriptions (distances) used on form 500

observations and the current descriptions

(distances) used presently (WMO code table

4377) especially for the lower and upper

scale limits.

24 WW 666	present weather Convert according to the Table 1 attached;

then translate into LMR format

667/668/669	Forms 555 & 556 use Beaufort weather codes

Convert according to table 1a. Then
translate to LMR format

25 W1 665 past weather	Code as reported; translate into LMR

Note: only minor description changes between

current past weather code and that used

for the Form 500 entries.

26 W2	2nd past weather Left blank; assign as missing. A second

past weather was not reported on a form	500.

27 SLP 707	sea level	Convert corrected barometer report in
/607 pressure inches or millimeters to millibars using	/708	the conversion of 1 inch = 33.8639
/608 millibars or 1 millimeter = 1.333224
millibars. If the corrected value is not	available then the correction must be made	using the proper procedures based on	whether it is an aneroid or mercurial	barometer. Translate into LMR.

704/604	Attached thermometers (degrees F/C respectively)

Note: The conversion program is designed to
accept other units of pressure other than those
designated for the form type because of some	inconsistencies experienced during keying. It	Performs checks to see if it can reasonably
determine if the units are in inches,
millimeters, or millibars.

28 T1 701	temp. indic. Set to 6; whole degree Fahrenheit

/601	Set to 0; degrees Celsius and tenths

29 AT 701	air temp. Convert from Fahrenheit to Celsius and	translate to LMR. C = (F-32)/1.8

/601	Degrees Celsius and tenths; translate to
LMR

30 WBT 702	wet bulb temp. Convert to Celsius same as AT; translate to LMR

31 DPT	dew point temp. Not reported; assign as missing

32 SST 744	sea surface temp. Convert to Celsius same as AT;translate to
LMR

33 SI	SST method indic. Assign indicator as provided in header
record using the following indicators:

Indicator	Description	Form 500, 511, 522, 523,	524, 525

0	Bucket	B

1	Intake	I

8	Blank

Forms 555 & 556 all require SST be determined by bucket,

for these two form types set SI = 0; However, we noted	instances where the observer marked through bucket and

inserted intake.

34 N	714	total cloud amt.	On the form 500 only, convert from the
radio message code (the reporting procedure

used by most observers on the form instead	of tenths which was official policy).
Convert these according to Table 2
(attached); translate to LMR. Anytime a	10 is reported as a total cloud amount on
the form 500 all the total cloud amounts can	be assumed to be in tenths for that voyage	and should be converted to eights according	to Table 2. All cloud amount values are to	be preserved by storing the original value	in the supplemental attachment. All other	form types in the 500 series are assumed to	have the cloud amounts reported in tenths	and should be converted to LMR accordingly.

35 NH 716	lower cloud amt.	Same procedure as for total cloud amounts,

including preserving the original value in	the supplemental attachment. If a 10 is	reported in the total cloud amount field	assume that the low cloud amounts are also in tenths and convert accordingly.

36 CL 720	low cloud type Translate directly into LMR format for

form 500. For forms 555 and 556 if the

low cloud type (720) is numeric translate

directly to LMR, if alpha move to the

CLDTY 1 (620) in the supplemental attachment.

Note: Table 3, illustrates the differences

in the meaning of the code values used	during the form 500 era and presently.

37 HI	cloud ht. indic. Assign height indicator as missing, because	cloud heights were not reported on a form	500.

38 H	cloud height Assign as missing; not reported

39 CM 721	middle cloud type Translate directly to LMR format (see CL
note) for form type 500. For forms 555 and	556 if the middle cloud type (721) is
numeric translate to LMR, if alpha move to CLDTY 2 (621) in the supplemental attachment.

40 CH 725	high cloud type Translate directly to LMR format (see CL note) for form type 500. For forms 555 and	556 if the high cloud type (725) is
numeric translate to LMR, if alpha move to CLDTY 3 (625) in the supplemental attachment.

41 WD	wave direction Assign as missing; not reported

42 WP	wave period Assign as missing; not reported

43 WH	754 wave height Assign as missing; state of sea reported which is unable to be converted to a height in half meters. Preserve reported (scale)	value in supplemental attachment.

Sea State

Scale	Description	Height of wave crest	Abbreviation

to trough

0	Calm	0	Calm

1	Smooth	less than 1 foot	Sm.

2	Slight	1 to 3 feet	Sl.

3	Moderate	3 to 5 feet	M.

4	Rough	5 to 8 feet	R.

5	Very Rough	8 to 12 feet	VR.

6	High	12 to 20 feet	H.

7	Very High	20 to 40 feet	VH.

8	Precipitous	over 40 feet	P.

9	Confused	-----------	Con.

Note: occassionally the word small is entered on the form, which we assume refers to the abbreviation 'sm' representing smooth.

44 SD 755	swell direction Assign as missing; reported in 8 pt. /803 direction

Direction of Swell

Scale	True Direction

0	No sea or swell

1	NE

2	E

3	SE

4	S

5	SW

6	W

7	NW

8	N

9	All directions or no definite direction

45 SP	swell period Assign as missing, not reported

46 SH	757 swell height Assign as missing, character of swell /804 reported. Preserve coded value in supplemental attachment.

Character of Swell

Scale	Description

0	No Swell

1	Low swell, short or average length

2	Low swell, long

3	Moderate swell, short

4	Moderate swell, average length

5	Moderate swell, long

6	Heavy swell, short

7	Heavy swell, average length

8	Heavy swell, long

9	Confused swell

47 C1	country code Assign as missing, not applicable

48 C2	2nd country code Assign as missing, not applicable

49 SC 661	ship course Translate directly to LMR format.

Note: code 0-8 are identical; LMR

accommodates a code 9 (unknown)

that is not reported on form 500.

If missing code as missing

50 SS 662	ship speed Translate directly to LMR format; code

matches LMR documentation for observations

prior to 1968 (date of code change)

51 A 663	bar. tendency Convert as recommended below; translate

into LMR format

A; characteristic of pressure tendency

WMO Code 200 (same as LMR)

0 = increasing, then decreasing; atmospheric pressure

same or higher than 3 hours ago

1 = increasing, then steady; or increasing then

increasing more slowly; atmospheric pressure now

higher than 3 hours ago

2 = increasing (steadily or unsteadily); atmospheric

pressure now higher than 3 hours ago

3 = decreasing or steady, then increasing; or increasing

then increasing more rapidly; atmospheric pressure

now higher than 3 hours ago

4 = steady; atmospheric pressure same as 3 hours ago

5 = decreasing, then increasing; atmospheric pressure

the same or lower than 3 hours ago

6 = decreasing, then steady; or decreasing then

decreasing more slowly; atmospheric pressure now

lower than 3 hours ago

7 = decreasing (steadily or unsteadily); atmospheric

pressure now lower than 3 hours ago

8 = steady or increasing, then decreasing; or decreasing

then decreasing more rapidly; atmospheric pressure

now lower than 3 hours ago

Form 500 (1938 & 1941 Observers Handbook)

0 = Rising, then falling *

1 = Rising, then steady; or rising, then rising more

slowly *

2 = Unsteady *

3 = Steady or rising *

4 = Falling or steady, then rising; or rising, then

rising more quickly *

* note: Barometer now higher than or the same as 3

hours ago

5 = Falling, then rising #

6 = Falling, then steady; or falling, then falling more

slowly #

7 = Unsteady #

8 = Falling #

9 = Steady or rising, then falling; or falling, then

falling more quickly #

# Note: Barometer now lower than 3 hours ago

Recommended conversion from Form 500 to LMR

From: To:

0 = 0

1 = 1

2 or 3 = 2

4 = 3

NA = 4 NA = Not Available (no code equivalent)

5 = 5

6 = 6

7 or 8 = 7

9 = 8

missing set to missing

52 PPP 664	amt. of SLP change Convert as indicated below; translate to

LMR format

Barometer Change (PP) is in a two digit code:

To convert to millibars multiply the code figure (01-99) by .02

e.g. 01 = 00.2 mbs, 29 = 05.8 mbs, 73 =14.6 mbs, 99 = 19.8 or greater (see note below). LMR requires ppp (millibars to tenths).

Note: should the value of the variation be 20.0 millibars or

more, "pp" should be reported as 99, and the actual amount of the

tendency, without regard to sign, should be given at the end of the

report in plain language, e.g. "Tendency 23.8 millibars."

53 IS	ice accretion Assign as missing; not reported

54 ES	ice thickness Assign as missing; not reported

55 RS	ice accretion	Assign as missing; not reported

rate

56 II	ID indic. Set to 10; composite information

57-

64 ID(8)	ID/call sign Assign 8 digit identifier as call sign.

Note: first two characters (57 & 58)

represent country of registry

(see list below) and the next six

digits (59-64) represent a single voyage

each numbered sequentially as they were

digitized. The 8 characters can be used

for track checking, but not for ship
identification.

Codes	Country

AS, OS	Austria

AU	Australia

BX	Belgium

CH	Chile

CI	China

CN	Canada

CU	Cuba

CZ	Czechoslovakia

DD, DL	Germany

DN	Denmark

DR	Dominican Republic

FI	Finland

FR	France

GR	Greece

HK	Hong Kong

HO	Honduras

IY	Italy

JP	Japan

MX	Mexico

NK	Nicaragua

NL	Netherlands

NO	Norway

PH	Philippines

PL	Poland

PM	Panama

PO	Portugal

RA, RS	USSR

SN	Sweden

SP	Spain

SW	Switzerland

TH	Thailand

TU	Turkey

UK	United Kingdom

US	United State of America

YG	Yugoslavia

65 OS	observation source Assign as missing

66 OP	observation plat. Assign as missing

67 T2	2nd temp. indic. Assign as missing; Wet bulb temperature

is reported on form 500.

68 IX	stn/weather indic. Assign as missing; not applicable

69 WX	wave per. indic. Assign as missing; not applicable

70 SX	swell per. indic. Assign as missing; not applicable

71 IRD	IMM receipt date Assign as missing; not applicable

72 A6	allowance 6 flag Assign as missing; not applicable

73 CK	checksum Perform as outline in LMR documentation

74 AC	attachment count Assign as described in LMR documentation

Irregular section to follow:

75 AL	attachment length

76 AID	attachment ID

77 AD	attachment data

Table 1.

(WW) Present Weather

* = WW code used on form 500

@ = WW code used for LMR (current 00-99 present weather code + description)

* @

00 = cloud development not observed.

01 = clouds generally dissolving or becoming less	developed.

00,01,

02,03-	02 = state of the sky unchanged.

03 = clouds generally forming or developing.

17- 04 = visibility reduced by smoke.

05- 05 = haze.

06 = widespread dust in suspension in the air, not	raised by wind at or near the station at time of	observation.

07 = dust or sand raised by wind at or near the station	at time of observation, but no well-developed dust	whirls or sand whirls and no dust storm or
sandstorm seen.

06- 08 = well developed dust whirls or sand whirls seen at	or near the station during the preceding hour or	at time of observation, but no dust storm or	sandstorm.

12- 09 = dust storm or sandstorm within sight at time of	observation, or at the station during the
preceding hour.

08- 10 = light fog (visibility 1,100 yards or more);
synonymous with European term "mist."

11 = patches of shallow fog or ice fog at the station,	not deeper than about 10 meters.

04- 12 = more or less continuous shallow fog or ice fog at	the station, not deeper than about 10 meters.

07- 13 = lightning visible, no thunder heard.

14 = precipitation within sight, not reaching the	surface of the sea

15 = precipitation within sight, reaching the surface	of the sea, but more than 5 kilometers from the	station.

10- 16 = precipitation within sight, reaching the surface	of the sea, near to, but not at the station.

11- 17 = thunderstorm, but no precipitation at time of	observation.

13,14,

15,19- 18 = squalls at or within sight of the station during	the preceding	hour or at time of observation.

16- 19 = funnel cloud or waterspout at or within sight of	the station during the preceding hour or at time	of observation.

Codes 20 to 29 refer to phenomena that occurred at the	station during the preceding hour but not at time of	observation:

20,21- 20 = drizzle (not freezing) or snow grains.

22- 21 = rain (not freezing).

23- 22 = snow.

24- 23 = rain and snow or ice pellets, type (a).

24 = freezing drizzle or freezing rain.

25- 25 = shower of rain.

26- 26 = shower of snow, or of rain and snow.

27- 27 = shower of hail (ice pellets, type (b), snow
pellets), or of rain and hail.

41,42- 28 = fog or ice fog.

28,29- 29 = thunderstorm (with or without precipitation).

Codes 30 to 99 refer to phenomena occurring at the ship	at time of observation:

31-	30 = slight or moderate dust storm or sandstorm has
decreased during the preceding hour.

18,

30,32-	31 = slight or moderate dust storm or sandstorm with no	appreciable change during the preceding hour.

33-	32 = slight or moderate dust storm or sandstorm has
begun or has increased during the preceding hour.

33 = severe dust storm or sandstorm has decreased
during the preceding hour.

34-	34 = severe dust storm or sandstorm with no appreciable	change during the preceding hour.

35 = severe dust storm or sandstorm has begun or has
increased during the preceding hour.

35,36-	36 = slight or moderate drifting snow generally low
(below eye level, less than 6 feet).

37-	37 = heavy drifting snow generally low (below eye
level, less than 6 feet).

38-	38 = slight or moderate blowing snow generally high
(above eye level, 6 feet or more).

39-	39 = heavy blowing snow generally high (above eye
level, 6 feet or more).

09-	40 = fog or ice fog at a distance at time of
observation, but not at the station during the	preceding hour, the fog or ice fog extending to a	level above that of the observer.

49-	41 = fog or ice fog in patches.

43-	42 = fog or ice fog (sky visible) has become thinner
during the preceding hour.

44-	43 = fog or ice fog (sky invisible) has become thinner
during the preceding hour.

45-	44 = fog or ice fog (sky visible) with no appreciable
change during the preceding hour.

40,46-	45 = fog or ice fog (sky invisible) with no appreciable	change during the preceding hour.

47-	46 = fog or ice fog (sky visible) has begun or has
become thicker during the preceding hour.

48-	47 = fog or ice fog (sky invisible) has begun or has
become thicker during the preceding hour.

48 = fog, depositing rime, sky visible.

49 = fog, depositing rime, sky invisible.

Codes 50 to 99 indicate precipitation at the station at	time of observation:

50,

51,57-	50 = drizzle, not freezing, intermittent, slight at
time of observation.

52-	51 = drizzle, not freezing, continuous, slight at time
of observation

53-	52 = drizzle, not freezing, intermittent, moderate at
time of observation.

54-	53 = drizzle, not freezing, continuous, moderate at
time of observation.

55-	54 = drizzle, not freezing, intermittent, heavy (dense)	at time of observation.

56-	55 = drizzle, not freezing, continuous, heavy (dense)
at time of observation.

56 = drizzle, freezing, slight.

57 = drizzle, freezing, moderate or heavy (dense).

58-	58 = drizzle and rain, slight.

59-	59 = drizzle and rain, moderate or heavy.

60,

61,67-	60 = rain, not freezing, intermittent, slight at time
of observation.

62-	61 = rain, not freezing, continuous, slight at time of
observation.

63-	62 = rain, not freezing, intermittent, moderate at time	of observation.

64-	63 = rain, not freezing, continuous, moderate at time
of observation.

65-	64 = rain, not freezing, intermittent, heavy at time of	observation.

66-	65 = rain, not freezing, continuous, heavy at time of
observation.

66 = rain, freezing, slight.

67 = rain, freezing, moderate or heavy.

68-	68 = rain or drizzle and snow, slight.

69-	69 = rain or drizzle and snow, moderate or heavy.

70,

71,77-	70 = intermittent fall of snowflakes, slight at time of	observation.

72-	71 = continuous fall of snowflakes, slight at time of

observation.

73-	72 = intermittent fall of snowflakes, moderate at time
of observation

74-	73 = continuous fall of snowflakes, moderate at time of	observation.

75-	74 = intermittent fall of snowflakes, heavy at time of
observation.

76-	75 = continuous fall of snowflakes, heavy at time of
observation.

76 = ice prisms (with or without fog).

78-	77 = snow grains (with or without fog).

78 = isolated star-like snow crystals (with or without
fog).

79-	79 = ice pellets, type (a) (sleet, U.S. definition).

80,81-	80 = rain shower, slight.

82-	81 = rain shower, moderate or heavy.

82 = rain shower, violent.

85-	83 = shower of rain and snow mixed, slight.

86-	84 = shower of rain and snow mixed, moderate or heavy.

83-	85 = snow shower, slight.

84-	86 = snow shower, moderate or heavy.

87-	87 = slight showers of snow pellets or ice pellets,
type(b), with or without rain or rain and snow	mixed.

88 = moderate or heavy showers of snow pellets or ice	pellets, type (b), with or without rain or rain	and snow mixed.

88-	89 = slight showers of hail, with or without rain or
rain and snow mixed, not associated with thunder.

89-	90 = moderate or heavy showers of hail, with or without	rain or rain and snow, mixed, not associated with	thunder.

91- 91 = slight rain at time of observation, thunderstorm	during preceding hour but not at time of
observation.

92 = moderate or heavy rain at time of observation,	thunderstorm during preceding hour but not at time	of observation.

92- 93 = slight snow, or rain and snow mixed, or hail, at	time of observation with thunderstorm during the	preceding hour but not at time of observation.

94 = moderate or heavy snow, or rain and snow mixed, or	hail, at time of observation with thunderstorm	during the preceding hour but not at time of

observation.

90,

93,95-	95 = thunderstorm, slight or moderate, without hail,
but with rain and/or snow at time of observation.

94,96-	96 = thunderstorm, slight or moderate, with hail at
time of observation.

97- 97 = thunderstorm, heavy, without hail but with rain	and/or snow at time of observation.

98- 98 = thunderstorm combined with dust storm or sandstorm	at time of observation.

99- 99 = thunderstorm, heavy, with hail at time of
observation.

Note: these conversions all agree with the Scale 3 conversions in the TDF-1100 Reference Manual with the following exceptions:

(1) Scale 3 did not cover present weather codes 04 and 18 in either the conversion section or those in the the 1942 code section that were not comparable. Here an 04 is converted to a 12 and an 18 to a 31.

(2) Scale 3 converts a 40 to a 12; here a 40 is converted to a 45

(3) Scale 3 convers a 42 to a 45; here a 42 is converted to a 28

(4) Scale 3 did not convert a 13 or 19 since they were not comparable in which we agree; however, in this conversion to keep from biasing the information towards fair weather both 13 and 19 were converted to a 18.

(5) Scale 3 originally did not convert 00-03 but later converted them to 02 to protect againt biasing any present weather summaries towards significant weather. Here 00, 01, 02 and 03 were also converted to an 02. Remember the original code value is retained in the supplemental attachment.

Table 1a

Beaufort weather CLICOM conversion LMR conversion

symbols codes codes

B (blue sky)	0	00

/clear/good

/fair/none/blue

C (cloudy)	2	03

D (Drizzle)	51	51

E (wet without rain)	14	21

F (fog)	12	47

G (gloomy weather)	16	16

H (hail)	88	89

K (smoke)	4	04

L (lightning)	13	13

M (mist)	10	10

O (overcast)	3	03

P (passing showers)	81	81

Q (squalls, rough)	97	18

R (rain)	61	61

S (snow)	71	71

T (thunder)	17	17

U (ugly weather)	18	07

V (unusual visibility-	0	00
exceptionally clear)

W (dew)	11	11

X (hoar frost)	48	48

Z (haze)	5	05

Fog (written out)	45	45

Funnel Cloud	19	19

Note: All these symbols can be used in combination (up to three). Whenever, this occurs always select the higher value based on the LMR code numbers

(e.g. OPQ = 81, CRZ = 61, CR = 61, CPH = 89, and OC = 03) with the following exceptions:

BC (partly cloudy) = 02

Any combination containing thunder (T = 17) should be coded in the 90s category, for example:

RT = 95

ST = 95

HT = 96 any combination with HT should = 96

RST = 95 and any combination (excluding H) with RT and ST = 95

CRT = 95

PRT = 95

CST = 95

PST = 95

The original keyed Beaufort weather values (or CLICOM conversion codes) will be placed in the supplemental atachment.

Note: Observers often made the following code interchanges in error. Efforts were made during the QC phase to correct as many of these errors as possible.

Examples of the most common problems:

Code	Code	Meaning	Observer Incorrect Interpretation

PS	passing showers, snow	passing shower

PC	passing showers, cloudy	partly cloudy

H	hail	haze

S	snow	showers

BH	blue skies, hail	blue skies, haze

Table 2.

N; Total Cloud Amount

N Form 500 Card Form 789

code value OKTAS TENTHS Code UK 1930 code

0 = 0 0 0 no observation

1 = 1 1 < 0.1 0.0-0.1

2 = 2 2 0.1 0.2

3 = 3 3 0.2-0.3 0.3

4 = 4 4 0.4-0.6 0.4

5 = 5 5 0.7-0.8 0.5

6 = 6 6 0.9 0.6

7 = 7 7 > 0.9 with 0.7

openings

8 = 8 8 Overcast 0.8

9 = 9(obscd) 9 Sky 0.9-1.0

obscured

10 = 10 by fog,

dust storm, or

other phenomenon

11 = - (dash)

Recommended Conversion to LMR

N Form 500 Card Form 789

code value OKTAS TENTHS Code UK 1930 code

missing 11 0

0 0 0 0 1*

1 1 1 1 or 2 1** 2#

2 2 2 or 3 3

3 3 4 3 4

4 4 5 4 5

5 5 6 6

6 6 7 or 8 5 7

7 7 9 6 or 7	8#

8 8 10 8 9#

9 9 9 ?

Note:

* convert 1 with no cloud type to 0

** convert 1 with cloud type(s) to 1

# Different from conversion of tenths to oktas

? coding of 88 in weather A/weather B with cloud details missing was	converted to 9 (sky obscured)

Table 3

CLOUDS: U.S. Merchant Marine Collection 1912-1946

The element cloud codes 720, 721, and 725 (CLDLOW, CLDMID, CLDHIH) represent the forms of low clouds (CL), middle clouds (CM) and high clouds (CH) respectively. These numeric codes range from 0 to 9 for each type and are defined similarly for the middle and high clouds as used today (WMO code tables 0515 & 0509); however, for the low cloud types only about half match the current code (WMO table 0513) closely while there are significant differences between the others. Our current plan is to map them directly into the cloud fields defined in the FM 13 Ship Code and the LMR.6 format documenting the differences in the metadata files with the following tables. The cloud codes keyed as 620, 621, and 625 are too different from the cloud types reported below (which began in the late 1930s) and should be transferred, as is, to the supplemental fields for retention and possible future use.

Cloud Type Table

LOW CLOUD TYPES

Code	720 (CLDLOW)	CL (FM13 Ship Code)

/	not applicable	Sc,St,Cu and Cb invisible
owing to darkness

0	No lower clouds	No Sc, St, Cu, or Cb
clouds present

1	Cumulus of fine	Cu with little vertical
weather	extent and seemingly
flattened, and/or ragged	Cu other than bad weather

2	Cumulus heavy and	Cu of moderate or strong
swelling, without	vertical extent, generally
anvil top	with protuberances in the
form of domes or towers,
with or without other Cu or	Sc, all having their bases	at the same level

3	Cumulonimbus	Cb the tops of which, at
least partially, lack sharp	outlines, but are clearly	not fibrous or anvil-
shaped; Cu, Sc, or St may	also be present

4	Stratocumulus formed	Sc formed by the spreading
by the flattening of	out of Cu; Cu may also be

cumulus clouds	present

5	Layer of stratus or	Sc not formed by the
stratocumulus	spreading out of Cu

6	Low broken-up clouds	St in more or less

of bad weather	continuous layer, and/or in
ragged shreds; but no
ragged St of bad weather

7	Cumulus of fine weather	Ragged St and/or ragged Cu,
and stratocumulus	both of bad weather,
usually below As or Ns

8	Heavy or swelling	Cu and Sc not formed by the
cumulus, or cumulonimbus,	spreading out of Cu; the
and stratocumulus	bases of the Cu and Sc at
different levels

9	Heavy or swelling cumulus	Cb with a clearly fibrous
(or cumulonimbus) and low	top, often anvil-shaped;
ragged clouds of bad	with or without other Cb,
weather	or Cu, Sc, St or ragged Cu
or St of bad weather

Note: codes 1,5,6 and 7 are	of equal priority. Choose	the cloud type that is
predominant

MIDDLE CLOUD TYPES

Code	721 (CLDMID)	CM (FM13 Ship Code)

/	Not applicable	Ac, As, and Ns invisible
owing to darkness, or
because of an overcast
layer of CL cloud

0	No middle cloud	No Ac, As or Ns clouds
present

1	Typical altostratus,	As, mostly semi-transparent
thin	through which the sun or
moon may be weakly visible,	as through ground glass

2	Typical altostratus,	Either As, most of which is
thick (or nimbostratus)	sufficiently dense to hide
the sun or moon; or
Nimbostratus

3	Altocumulus, or high	Ac, mostly semi-transparent
stratocumulus, sheet at	cloud elements change only
one level only	slowly and are all at a
single level

4	Altocumulus in small	Patches (often almond or
isolated patches; individual	fish shaped) of Ac, mostly

clouds often show signs of	semi-transparent; clouds
evaporation and are more or	occur at one or more levels

less lenticular in shape	and continually change in
appearance

5	Altocumulus arranged in	Ac, semi-transparent, in
more or less parallel bands,	bands, or Ac in one or more
or an ordered layer	layers, progressively
advancing over the sky	invading the sky; these Ac
clouds generally thicken as	a whole

6	Altocumulus formed by a	Ac resulting from the
spreading out of the tops	spreading out of Cu (or Cb)
of cumulus

7	Altocumulus associated with	Either: (a) Ac in two or
altostratus, or altostratus	more layers, opaque in
with a partially altocumulus	places, not increasing.

character	(b) Opaque layer of Ac, not
increasing. (c) Ac together	with As or Ns

8	Altocumulus castellatus, or	Ac with sprouting like
scattered cumuliform tufts	small towers or
battlements, or Ac having	the appearance cumulus-
shaped tufts

9	Altocumulus in several	Ac of a chaotic sky,
sheets at different levels,	generally at several levels

generally associated with

thick fibrous veils of cloud

and a chaotic appearance of

the sky

HIGH CLOUD TYPES

Code	725 (CLDHIH)	CH (FM13 Ship Code)

/	Not applicable	Ci, Cc and Cs invisibe
owing to darkness, or
because of a continuous

layer of lower clouds

0	No upper clouds	No Ci, Cc or Cs clouds
(no high clouds)	present

1	Cirrus, delicate,	Ci in forms of filiments,

not increasing, scattered	strands or hooks, not
and isolated masses	progressively invading the
sky

2	Cirrus, delicate, not	Either: (a) Dense Ci in
increasing, abundant but	patches or tangled sheaves,
not forming a continuous	not increasing, which
layer	sometimes seem to be the
remains of the upper part	of a Cb. (b) Ci with

sproutings like small
turrets or battlements, or	Ci having the appearence of	cumulus shaped tufts

3	Cirrus of anvil clouds,	Dense Ci, often anvil-
usually dense	shaped, being the remains
of the upper parts of a Cb

4	Cirrus, increasing,	Ci in the forms of hooks
generally in the form	and/or filaments,
of hooks ending in a point	progressively invading the
or in a small tuft	sky; they generally become
thicker as a whole

5	Cirrus (often in polar	Same as code 6 below,
bands) or cirrostratus	except that the continuous

advancing over the sky	veil does not reach 45o
but not more than 45o	above the horizon

above the horizon

6.	Cirrus (often in polar	Ci (often in converging

bands) or cirrostratus	bands) and Cs, or Cs

advancing over the sky	alone; in either case

but more than 45o	spreading over the sky

above the horizon	and generally thicking,

the continuous veil extends
more than 45o above the
horizon, but does not cover	the whole sky

7	Veil of cirrostratus	Veil of Cs covering the
covering the whole sky	whole sky

8	Cirrostratus not increasing	Cs not increasing and not

and not covering the	covering the whole sky

whole sky

9	Cirrocumulus predominating,	Cc alone, or Cc and /or Cs,

associated with a small	but the Cc is predominant

quantity of cirrus

ATTACHMENT 4 - Supplemental Attachment

Field	Element	Positions	Description

No. No.

1	1-3	Form Type (e.g. 500, 601, 721, etc.)

2	694	4	Day of the week (GMT)

3	693	5-6	Greenwich Mean Time (00-23)

Note: GMT is entered into the supplemental attachment for those forms that report both local and GMT so a comparison can be made after the LMT is converted to GMT to see that it agrees with the GMT entered by the observer.

4	649	7	Octant ( 0-3; 5-8; missing = space)

5	711	8-9	Beaufort Force (0-12; a dash = 13 or -)

6	610	10	Visibility (0-9)

7	666	11-12	Present weather (00-99)

8	665	13	Past Weather (0-9; a dash = 11 or -)

9	667	14-19	Beaufort weather ( as initially coded /668 {alpha characters} or converted by

/669 CLICOM {numeric code values}

10	606	20-21	Barometer as coded (PP; 00-99)

11	707	22-25	Barometer as read (inches to
/607 hundreths or millimeters to tenths)

Note: The instrument correction

in the header record is not always in

the same units as the "barometer as read"

units.

12	26-29	Attached Thermometer

704	Fahrenheit (whole degrees)

/604	Celsius (to tenths of a degree)

Note: It is not always the case that if the

barometer is reported in inches that the	attached thermometer is in Fahrenheit or if

in millimeters the temperature is in
Celsius. There is occasionally a mixture.

13	708	30-33	Barometer as corrected (in. to hundreths)

/608 Barometer as corrected (mm to tenths)

If both are reported (608/708) select

the one that has the units that agrees with

field # 9 (barometer as read), otherwise, convert the one that is available to agree.

14	34	Barometer type

15	35-39	Barometer correction

16	40	Air Temperature Indicator (S = stationary
thermometer; P=psychrometer; O= other)

17	714	41-42	N, total cloud amount (as recorded in tenths	or code) (0-10; a dash = 11 or -)

18	716	43-44	Nh. Low cloud amount (as recorded in tenths
or code) (0-10; a dash = 11 or -)

19	620	45-48	Cloud Type

e.g. FT511/FT601/FT701 - Cloud type 1

FT522/FT523 - high cloud type

20	615	49-52	Cloud movement (direction)

/640	or

direction of upper (high) cloud movement

Note: This field (positions 49-52) is the only one used for those logbooks that only contain one column for cloud movement, e.g.`Direction Moving From' as reported on form type 604.

21	621	53-56	Cloud Type

e.g. FT511/FT601/FT701 - Cloud type 2

FT522/FT523 - middle cloud type

22	641	57-60	Direction of middle cloud movement

23	625	61-64	Cloud Type

e.g. FT511/FT601/FT701 - Cloud type 3

FT522/FT523 - low cloud type

24	645	65-68	Direction of low cloud movement

e.g. FT522/FT523/etc.

25	754	69-71	State of Sea (alpha or numeric)

/657 Note: there is a problem between the
conversion codes and the non-converted codes	in the range of 1-10 since they have
different meanings, yet appear the same.

26	807 72-75	Sea (wind wave) Direction (right justify - 8 /655 pt scale; coded 0-9 or coded using alpha representation; a dash = 11 or -)

27	755 76-79	Swell Direction (right justify - 8 pt scale;	/803	coded 0-9 or coded using alpha representation; a dash = 11 or -)

28	757 80-82	Character of swell (same as state of sea)

/804

29	605 83	Temperature difference (air-water) in

code (0-9)

Note: observer often entered

actual difference instead of

code. This can generally be checked

since both air and sea temperatures are

part of the basic record.

30	663	84	Characteristic of change of the barometer

/805 (a) in 3 hours (0-9; a dash = 11 or -)

Note: exception for form 703, a plus or

minus will be placed in this field to

indicate the direction of the 2 hour

pressure change reported in element 28

below (pp).

31	664	85-86	(pp) Barometer change in two digit code
/806	(00-99)

Note: exception for form 703, place the

two hour pressure change in this field

(hundreths of inches)

32	87-112	Ship Name (26 characters allocated)