PREPARATION OF CHARTS B5-23 
11.1 Altitude. Altitude computations are made directly within the CPD 
blocks; therefore, altitude entries will be made to the nearest whole 
meter at all computed levels. Thickness between strata will also be en- 
tered in the blocks provided to the nearest whole meter. For example, 
1,544 meters will be entered as 1544, and 21,456 meters as 21456. 
Altitudes pertaining to intermediate constant pressure levels are 
read from the plotted PA curve; therefore, altitude entries at the 
non-computed levels will be made to the nearest ten meters. Prefix a 
minus sign to entries pertaining to levels below sea level. 
11.2 Temperature. Enter in degrees and tenths (see §B5-11.7). Enter 
a dash when data are missing. 
11.3 Relative Humidity. Enter to the nearest whole percent, with 100 
percent entered as 100 (see §B5-11.7). If the relative humidity data are 
missing enter a dash. Enter a dash for relative humidity when the tem- 
perature is colder than -40.0°C. 
11.4 Dewpoint. Enter the dewpoint temperature in degrees and tenths 
(see §B5-11.7). Whenever the temperature or relative humidity is mis- 
sing, and whenever the temperature is colder than-40.0°C, the dewpoint 
will be entered as a dash. 
11.5 Dewpoint Depression. Enter dewpoint depression to degrees and 
tenths (see §B5-11.7). When either the temperature or the dewpoint is 
missing or both are missing, enter a dash. 
11.6 Wind Data. Wind data will be taken from the wind curve at altitudes 
corresponding to the altitude of the constant pressure surfaces. Only 
rawin or rabal data secured with the raob balloon will be entered on this 
form. Wind directions will be entered to the nearest whole degree and 
wind speeds will be entered to the nearest whole meter per second (see 
§B5-11.7). A single zero will be entered ineach space for direction and 
speed whenever the wind is calm. When data are missing, or when the 
level is below the surface, enter a dash. 
11.7 Examples. Examples of data entries in the CPD blocks. 
Altitude of 44 meters entered as 44. Altitude of 21,456 meters en- 
tered as 21456. 
Temperature of 2.4°C entered as 2.4. 
Temperature of -7.3°C entered as -7.3 
Temperature of -57.3°C entered as -57.3 
1-1-69 FMH#3 
