Training Guide in Surface Weather Observations

1 METAR KWSH 031558Z 11014KT 7SM !SHRA BKN040 28/21 A3005 Training Guide inSurfaceWeather ObservationsMAY DEPARTMENT OF COMMERCENATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATIONN ational Weather ServiceOffice of Systems OperationsSystems Integration DivisionObserving Systems Branch1325 East-West HighwaySilver Spring, Maryland 20910 national Weather SERVICE Serving the Nation Since 1870 iPREFACEMETAR/SPECI is the international standard code for hourly and special Surface Weather METAR acronym roughly translates from the French as Aviation Routine Weather Report. Aspecial report, SPECI, is merely a METAR-formatted report which is issued on a non-routine basis asdictated by changing meteorological conditions.

2 The SPECI acronym roughly translates as AviationSelected Special Weather Weather Service Observing Handbook No. 7, Part I (WSOH #7), and national Weather ServiceObserving Handbook No. 8 (WSOH #8) prescribe aviation Weather observing, reporting, and codingprocedures applicable to taking and reporting manual Surface Observations . They provide a frameworkwithin which meteorological phenomena can be identified and reported in a standardized andunderstandable format. The type of station you are assigned to will determine which national WeatherService observation Handbook is to be used for your station s Surface Weather observing #7 provides procedures and practices for NWS and NWS-contract personnel.

3 WSOH #8prescribes procedures and practices for Supplementary Aviation Weather Reporting Stations (SAWRS). Training Guide in Surface Weather Observations is designed to provide additional information inobserving, recording, and coding of manual Surface Weather reports. The Training Guide doesn t includeeverything you need to know. Therefore, it is necessary to use it in conjunction with your station you ve finished reading a chapter in your station s WSOH, read the discussion in the trainingguide. When you are confident and familiar with the contents of both, proceed to the review questionsat the end of each chapter. Answer each question, but DO NOT guess at the answers . If in doubt, lookup the answer in the appropriate instructions.

4 This will help you become more familiar with answers to review questions can be found in appendix A. Use these answers only afteranswering all questions in the chapter. If you made a mistake, locate the appropriate instructions anddetermine where you went the Observing and Coding Exercises and the Quality Control Exercises in Chapter 9 only afterall other chapters in the Training Guide are completed. Correct answers to the exercises can be found inAppendix this Training Guide provides a wide spectrum of information on Surface Weather Observations ,some of the information may not be applicable to a station s observing program. For example, SAWRSare not required to provide 3- and 6-hourly precipitation amounts, 24-hour precipitation amounts, snowdepth on the ground, or water equivalent of snow on the ground data; so a student working at a SAWRS would not need to study this information.

5 Therefore, students should consider only the information inthis study Guide that is applicable to their station s observing program. iiiiiTable of 1 - and Format of the Manual of Report - Identifier - Group - Modifier - Between Transmitted Coded Report and MF1M-10 Observational 2 - Group - dddff(f)Gff(f) Wind Direction - Shifts ..2-2 REVIEW 3 - Visual 4 - PRESENT of Present Weather Group(s)..4-7 REVIEW 5 - SKY and Ceiling of Cloud Height 6 - TEMPERATURE AND DEW Between Coded Report and MF1M-10 Temperature and Dew the Dew Temperatures from Minimum and Maximum Thermometer Temperature System (MMTS)..6-15 REVIEW 7 - Setting - Elevation - Between Coded Report and MF1M-10C Setting 8 - of the More Important Between Coded Report and MF1M-10 9 - REVIEW EXERCISESOBSERVING and CODING CONTROL A - answers TO CHAPTER and REVIEW EXERCISESANSWERS TO CHAPTER TO OBSERVING and CODING EXERCISES - CHAPTER TO QUALITY CONTROL exercise - CHAPTER B - DEW POINT C - TRANSMISSION FORM FOR MANUAL Observations ,WS Form D - ORDER OF OBSERVING The MF1M-10A, B, and C have the same column numbers and 1 GENERALThis chapter introduces you to the Aviation Weather observation and some of the procedures used inthe observing program.

6 General The Aviation Weather ObservationAn Aviation Weather observation is used to report the various meteorological elements that togetherdescribe the atmosphere as observed and evaluated from the observer s position. The meteorologicalelements normally observed are: Wind, Visibility, Present Weather , Sky Condition, Temperature, DewPoint, Altimeter Setting, and Remarks. Learning what to observe and how to report your observation is described in national Weather ServiceObserving Handbooks (WSOH #7 and WSOH #8). The format of these Handbooks is such thatinformation concerning an element is contained in its named chapter. A separate chapter covers codinginformation for all elements and information for entries on Meteorological Form 1M-10 (MF1M-10) forall elements provided in separate Meteorological Form 1M-10 (A, B, and C)1MF1M-10 (A, B, and C) are the standard forms used to log Observations .

7 The form your station usesis the official record of Observations taken and disseminated by your station. If you make a mistake onthe form, correct the error with the same black ink used to record the observation . Whether the error wasdiscovered before or after the dissemination of the observation , correct the erroneous data by clearlydrawing a single line through the error. Do not erase or obliterate the entry by writing over it or bycovering it accuracy of the actual time of the observation is of the utmost importance in aviation safetyinvestigations. Therefore, the station clock needs to be checked daily at part-time stations, on each shiftat full-time stations, or if there is an aircraft mishap.

8 Time checks are logged in column 65 of the second working day of the following month, send the originals of all MF1M-10 s used duringthe month to the national Climatic Data Center. SAWRS send their original MF1M-10C forms usedduring the month to the station designated by the NWS regional headquarters. This station will checkthe forms and advise the SAWRS of any corrections required on the forms by means of WS Form B-14, Notice of Corrections To Weather Records. Make corrections to the associated MF1M-10 forms thatare on hand. SAWRS with more than one observer shall post the B-14 so that all observers can reviewit. These notices are an excellent aid for the station s on-going Training and quality control the MF1M-10 is reviewed, the correction notices along with the associated copies of the weatherrecords shall be retained in accordance with the local guidelines provided by the supervising office.

9 Iflocal guidelines were not provided, you may discard the records when they are 90 days Content and Format of the Manual METAR/SPECIThe following is an overview of the various elements in a METAR/SPECI report. Each element isdescribed in the following paragraphs and chapters. Each element or group is separated by a space ina transmitted Body of report.(1)Type of Report - METAR or SPECI(2)Station Identifier - CCCC(3)Date and Time of Report - YYGGggZ(4)Report Modifier - CORnnnxxx(5)Wind - dddff(f)KT_dddVddd(6)Visibility - VVVVVSMRRRRRR(7)Runway Visual Range - RDD/VVVVFT orRRNNNNXXXXRDD/VVVVVVVVVFT(8)Present Weather - w0w0sssssssss(9)Sky Condition - NNNhhh or VVhhh or SKCdd(10) Temperature and Dew Point - T0T0/T0T0 HHHH(11) Altimeter - Section of Report - RMK(1)Manual and Plain Language(2)Additive Type of Report - METAR/SPECIThe type of report is the first element of the coded type of report shall be METAR for a routine report and SPECI for a special report.

10 Transmittedreports shall always begin with either METAR or SPECI, entered as M or S in column 1 of METARMETAR is a routine scheduled observation and is the primary observation code used in the United Statesto satisfy requirements for reporting Surface meteorological data. METAR contains a report of wind,visibility, present Weather , sky condition, temperature, dew point, and altimeter setting collectivelyreferred to as the body of the report. In addition, information that elaborates on data in the body ofthe report may be appended to the METAR. This significant information can be found in the sectionreferred to as Remarks. SPECISPECI is an unscheduled observation . SPECI Observations are taken when specific Weather conditionshave been met or observed (noted).