1. Wind speed in knots. Conversions are given in: 



Table 13 (meters/second to knots) 



Table 1^+ (miles/hour to knots) 



Table 15 (kilometers/hour to knots) 



Table l6 (feet/second to knots) 



2. Wind force according to the Beaufort scale as defined 

 by Table 17. (Do not use WMO Code ll^ti;. ) 



IMPORTAJNT: The unit not used, i.e., speed or force should be 

 crossed out at the top of the column of the data 

 form. 



Columns 5^-56 



BAEOMETRIC PRESSURE 



Enter barometric pressure in millibars. Enter tens, units, and 

 tenths only. (Example: 1012.62 = 12.6) The recordable range is 9^5.0 to 

 1044.9 mbs. Enter pressure falling outside this range in the Remarks space 

 of the data form. Table I8 converts inches to millibars. Table I9 con- 

 verts millimeters to millibars. 



Columns 57-62 



AIR TEMPERATURE 



Enter the dry bulb temperature in Columns 57-59 and the wet bulb 

 temperature in Columns 6O-62 in degrees centigrade to tenths. Indicate 

 negative temperatures by a prominent red dash over the numeral (s) in 

 Column (s) 57 and/or 60. Table 20 converts °F. to °C. If temperatures are 

 reported to whole degrees Fahrenheit, round the centigrade conversions to 

 whole degrees, and leave Columns 59 and/or 62 blank. 



Columns 63-64 



WEATHER 



There is a choice of two types of entries for weather. 



1. Enter an X in Column 63 and enter the weather in Column 64 

 according to the single digit WMO Code 4501 as shown in 

 Table 21. This is the preferred weather code. Conversions 

 from other weather codes are given in Tables 22 and 23- 



2. Enter present weather in Columns 63 and 64 according to the 

 two-digit WMO Code 4677 as shown in Table 24. Because code 



figures 00 through 03 are not descriptive of present weather. 

 Code 4501 is preferred instead of these code figures. 



