CHAPTER 11 



WATCH ROUTINES (CONTINUED) 



PLOTTING AND ANALYZING 



Map plotting and analysis are two of the job 

 functions that may be required during a watch 

 period. This is especially true during a fac- 

 simile circuit outage, when no analyzed prod- 

 ucts are available. The training you received 

 in map plotting and map sketching, while at 

 the Aerographer's Mate "Al" School, gave you 

 a basic understanding of the often used codes. 

 In chapter 10 some of these codes which you 

 have already learned were reviewed and new 

 codes were introduced with which you may not 

 be familiar. 



The maps and charts that you will plot 

 and sketch are of prime importance to all con- 

 cerned because from these maps and charts 

 you are able to locate pressure areas, fronts, 

 precipitation areas, ridges, troughs, and num- 

 erous other meteorological phenomena of great 

 importance. The maps and charts that you plot 

 are determined by the geographical location of 

 your weather station, its operational require- 

 ments, and its area of responsibility. 



A thorough knowledge of the codes used and 

 the employment of good map plotting practices 

 should make you an excellent map plotter. 



SURFACE CHARTS 



The surface synoptic chart, when plotted and 

 analyzed, is one of the "basic tools" of a fore- 

 caster. Accurate plotting of the chart is es- 

 sential. Three things, in the order of their 

 importance, for which the plotter of the chart 

 must strive are ACCURACY, NEATNESS, and 

 SPEED. 



Outline charts for selected areas of the world 

 are provided for the plotting of synoptic weather 

 reports (reports of observations made at weather 

 stations over a large area at a given time). 



These charts are termed Weather Plotting Charts. 

 The DOD number, title, map projection, scale, 

 and illustration of the various charts are found 

 in the latest edition of the Catalog of vVeather 

 Plotting Charts (NW 50-1G-518). 



A small station circle is printed on the 

 charts at the geographical location of the major 

 reporting stations. On maps, where the density 

 of reporting stations is a maximum for the 

 scale of the map, station circles are placed in 

 the general location of the station. Stations are 

 identified on the printed map by their assigned 

 station numbers adjacent to the station circle. 



Not all reporting stations are shown on the 

 charts. When it is desirable to enter a report 

 from one of these stations, the person plotting 

 the map draws a circle in the location of 

 the station. To facilitate locating stations, all 

 ships and stations should have a master plot- 

 ting chart which shows all station locations 

 by correctly positioned station circles with both 

 the station index number and name of the sta- 

 tion. 



This chart can be kept up to date by re- 

 ferring to the Air vVeather Service Manual 

 105-2 Vol-II and the latest changes to it. For 

 every area of International Index Number Sta- 

 tions, there is a master plotting chart which 

 may be obtained by request to the nearest Stock 

 Point. 



The term "weather map" is applied to a 

 weather plotting chart after the synoptic re- 

 ports have been entered around the station circle 

 as shown in figure 11-1. The term is also 

 applied to the chart after the analysis has been 

 made. 



There is neither a specified allowance nor 

 an initial distribution of meteorological plotting 

 charts. The responsibility for requisitioning the 



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