Chapter 10 — WATCH ROUTINES 



Local Observations 



Local observations may be taken and re- 

 corded at any weather observing station, for 

 any meteorological situation which is estab- 

 lished locally or, in the opinion of the observer, 

 is significant to Local operations. A Local 

 observation, however, must be taken and re- 

 corded immediately following notification of an 

 Aircraft Mishap (other than an inflight emer- 

 gency) unless there has been an intervening 

 R or S observation. Upon notification of an 

 inflight emergency, intensify the weather watch, 

 taking and disseminating weather data as nec- 

 essary to ensure maximum support to the air- 

 craft in distress. If the end result is an aircraft 

 accident or incident, take a Local observation, 

 including all elements normally included in an 

 R observation with the exception of sea level 

 pressure. Include any other data deemed ma- 

 terial to the accident/incident in the remarks 

 column of MF1-10 and NWSC form 3140/8. 

 Include the remark "ACFT MISHAP" in paren- 

 theses, but do not transmit this remark if the 

 observation is disseminated. 



Preparation of Forms 



Enter observations legibly and in chronolog- 

 ical order, restricting data as far as possible 

 to the columns appropriate to them as indicated 

 by the column headings. Ditto marks must not 

 be used. Use a black lead drawing pencil, grade 

 2 or 2H, employing sufficient pressure to en- 

 sure legible copies and ample contrast for 

 photographic reproduction. Test the impression 

 by holding the completed form at arm's length 

 in normal light. If all entries are easily read 

 and completely legible, the impression is sat- 

 isfactory. Numbers, symbols, and letters must 

 be of such size as to fill three-quarters of 

 the vertical space between lines. 



Prepare MF1-10 in duplicate, at least. Un- 

 less otherwise specified, start a new page every 

 day with the first observation having an ascribed 

 time that is both later than 0000 LST and later 

 than the ascribed time of the observation having 

 a standard (reference) time of 0000 LST. Use 

 additional pages as required. Aboard Navy 

 ships, an NWSC form 3140/8 is prepared in 

 duplicate, and a new NWSC form 3140/8 is 

 started daily at midnight Greenwich mean time. 



MISSING DATA. — Enter "M" In individual 

 columns to indicate that data normally entered 



are missing EXCEPT that "/** is entered in 

 3- and 6-hourly code groups, in column 13. 

 Explain briefly the necessity for "M" or "/" 

 entries in block 90. 



PARENTHESES. — Data entered in parenthe- 

 ses are for statistical purposes only and are 

 not to be transmitted. 



LATE OBSERVATIONS. — When an observa- 

 tion has been taken late and no appreciable 

 changes have occurred since the scheduled time, 

 enter the entire observation in black pencil 

 and enter "NIL" in Col. 13. When conditions 

 have changed appreciably since the scheduled 

 time, estimate the conditions probable at the 

 observation time, using recording instruments 

 wherever possible, and enter the observation 

 in red pencil. The observation is not trans- 

 mitted but may be used for computation of 

 sums and averages. 



CORRECTIONS. — Enter corrected data on 

 MF1-10 and NWSC form 3140/8 as follows: 



1. Error discovered before report is dis- 

 seminated, locally or longline — either erase the 

 erroneous data from all copies and record 

 corrected data, or draw a line through the 

 erroneous data and enter corrections in the 

 appropriate blocks on the next line or in col. 

 13, appropriately identified. 



2. Error discovered after report is dissem- 

 inated, either locally or longline — draw a red 

 line through the erroneous entry and enter 

 correction in red above it on all copies. If 

 insufficient space is available, enter correc- 

 tion in red, appropriately identified in column 

 13; e.g., SLPRES 196, DWPNT 57, ALSTG 969, 

 etc. 



If the correction is transmitted over long- 

 line teletypewriter circuits, enter "COR" in 

 red in column 13, followed by either the time 

 (GMT) the report is delivered to communica- 

 tions personnel, or the time (GMT) the ob- 

 server transmits the report. When the correction 

 is only disseminated locally, enter the time 

 (GMT) the report was disseminated following 

 "COR." 



WEATHER OBSERVATIONS DURING RADIO 

 SILENCE!. — The taking and recording of weather 

 observations are continued for local operational 

 and climatological uses regardless of conditions 



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