AEROGRAPHER'S MATE 3 & 2 



protected from soil and wrinkling. Most of these 

 completed forms are eventually microfilmed. 



OPNAV 3140-14 (MF5-20N). — Used to enter 

 elevation, azimuth angles, altitudes, horizontal 

 distances, slant ranges, and code data for 

 transmission of winds — aloft observations. Ad- 

 ditional columns are provided for shipboard 

 computations. 



OPNAV 3140-27 (NAVY WINDS ALOFT 

 PLOTTING CHART). — A chart used by the Navy 

 to plot computed wind direction and speed to 

 corresponding altitudes for coding purposes. 



OPNAV 3140-2 (RECCO FORM). — A form for 

 entering coded data of reconnaissance flights 

 from participating aircraft. Instructions for en- 

 tries are contained on the form. 



MF1-12 (PIREPS). — A form used to record 

 pilot reports prior to dissemination. 



MF31A, B, AND C (DOD-WPC 9-31A, B, C) 

 ADIABATIC CHARTS. — A series of three charts 

 for various heights, used to plot, compute, 

 and encode radiosonde data. 



Complete instructions for entries on all of 

 the above forms, with the exception of OPNAV 

 3140-2, can be found in the appropriate Federal 

 Meteorological Handbooks. 



Upper Air Codes 



As with all meteorological data, ea6e of 

 dissemination of upper air observations Is ac- 

 complished by coding the information in ac- 

 cordance with standards set forth in the Codes 

 Manual and Federal Meteorological Handbooks 

 No. 4 and 6. 



The following Is a brief description of the 

 more frequently used codes. For a more com- 

 plete coverage, along with some examples, 

 refer to the applicable Federal Meteorological 

 Handbook. 



LAND UPPER WIND CODE (FM 32. ( )).— The 

 upper wind code for land stations, FM 32. ( ), is 

 designed to allow the reporting of wind con- 

 ditions in the upper air. It is a relatively 

 easy code to learn, but there are many techni- 

 calities and variations to the code, and these 

 will have to be studied carefully. 



The WMO symbolic form of the upper wind 

 code, FM 32. ( ), Is divided into four parts — 

 A, B, C, and D. Parts A and B are confined 



to data up to and including the 100-mb level, 

 and parts C and D contain data above this 

 level. 



Section 1 of all four parts of the code con- 

 tains the identification and position data. Sec- 

 tion 2 of Part A contains data for the standard 

 isobaric surfaces of 850, 700, 500, 400, 300, 

 250, 200, 150, and 100 mb; and Section 2 of 

 Part C contains data for the standard isobaric 

 surfaces of 70, 50, 30, 20, and 10 mb when 

 pressure measurements and wind data are ob- 

 tained simultaneously from + Jie sounding. Section 

 3 of Parts A and C contain data for the level (s) 

 of the maximum wind(s), with altitudes given 

 in pressure in units of 1 mb or In units of 

 geopotential decameters. Section 4 of Parts 

 B and D contain data for fixed regional and/or 

 significant levels, with altitudes given in units 

 of 300 or 500 meters or significant levels with 

 altitudes given in pressure to a whole millibar 

 when pressure measurements and wind data 

 are obtained simultaneously from the sounding. 



SHIP UPPER WIND CODE (FM 33.( )). — The 

 WMO symbolic code form of the shipboard upper 

 wind code, FM 33.( ), is similar to the WMO 

 land station upper wind code. The significant 

 differences are the replacement of the station 

 Identifiers with the ship's position groups and 

 the inclusion of the Marsden Square Number 

 group, MMMU La U L (used to verify the ship's 

 position), following the position data in Section 

 1 of all parts. 



LAND STATION RADIOSONDE CODE (FM 

 35. ( )). — The complete radiosonde report is di- 

 vided Into four parts — A, B, C, and D — each 

 of which is an individual message complete with 

 position groups and separation signal. Part6 A 

 and C are specified for worldwide distribution 

 and Parts B and D for areas of continental 

 or WMO regional size. The United States (WMO 

 Region IV) collects Parts A and B (data up to 

 and including the 100-mb level) In a single 

 message which is referred to as the first trans- 

 mission and Parts C and D (data above 100 

 mb) as the second transmission. 



SHIPBOARD RADIOSONDE CODE (FM 

 36. ( )). — The symbolic form of the radiosonde 

 code used by U.S. Navy ships Is basically the 

 same as the land station radiosonde code. The 

 significant difference is the position symbolic 

 groups used in Section 1 in all parts of the 

 shipboard code. 



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