weather station handbook - table of contents, introduction
TRANSCRIPT
A publication of theNational WildfireCoord inating Group
Sponsored byUnited StatesDepartment of Agriculture
United SlatesDepartment of Interior
National Association 01State Foresters
PMS 426-2NFES 2140
Weather StationHandbook anInteragency Guide forWildland ManagersArnold I. FinklinWilliam C. Fisc her
MARCH 1990
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Weather Station Handbookan Interagency Guide forWildland ManagersArnold I. FinklinWill iam C. Fischer
TheNational WiJdfjre CoordinatingGroup has developedthis information for theguidance 01itsmember agencies and isnot respotlsble for theinterpretarion oruse of this information by anyoneexcept its memberagencies. Th9 use of tradeor firm nam8'S in this 1XJblicarion is for reade' information and does not implyendorsement by the National WifJf jr9 Coordi(J;Jfing Gro up of any product orservice.
Additional copies of this publication may be ordered from:
Nations/ Interagency Fire CenterA ITN: Supply
3833 S. Development AvenueBoise, Idaho 83705
Order NFES • 2140
THE AUTHORS
ARNOLD I. FINKUN has worked in the field of meteoro logy since 1949. He was a meteorologist with Intermountain ResearchStation's Fire Science s Laboratory , Missoula. MT,from 1967 until his retirement from the Foresl Service in 1987. Specializingin d imalology. he holds a master's degree in atmospheric science from Colo rado Sla te University.
WILLIAM C. f iSCHER is a research forest er at Intermountain Rese arch Stat ion's Fire Sciences laboratory, Missoula, MT. Heis currently assigned 10 the Prescribed Fire and Fire Effects research work unit. Belore joining the Iaboratory in 1966 he wasemployed as a forester on the Boise National Forest in Idaho. Mr. Fischer is a 1956lorestry graduate of the University ofMichigan.
The Intermountain Research Station provides scientif ic know ledge and technology to impro ve management , protection. anduse of the torests and range lands of the Intermountain West. Research is designed 10meet the needs 01 Nat ional Forest managers , Federal and State agencies. industry. acad emic institutio ns. public and private organizations. and individuals . Resulls 01resea rch are made ava ilable throug h publications, symposia, .....orkshops. t raining sessions. and personal contact s.
The Intermountain Research Stat ion territory includes Montana. Idaho. Utah. Nevada. and .....estern Wyoming . Eig hty·fivepercent of the land s in the Stat ion area , about 231 million acres, are classified as forest or rangeland. They ind ude grasslands,deserts, shrublancs. alpine areas. and forests . The y provid e liber lo r forest industries, minera ls and fossil fuels lor energy andindustrial development, wate r fOfdomestic and industrial consumption. forage for livestock and wildlife. and recreation oppo rtunities lor millions of visitors.
Several Station units conduct rese arch in add itional weste rn States, or have missions that are nationa l or international insccoe.
Station laboratories are located in:
Boise, Idaho
Bozeman. Montana (in cooperation with Montana State UOIversity)
l ogan. Utah (in cooperation with Uta h State Universrty)
Missoula. Montana (in cooperation with the University 01 Montana )
Moscow, Idaho (in cooperation with the University 01 Idaho)
Ogden. Utah
Provo, Utah (in cooperation with Brigham Young University)
Reno, Nevada (in cooperation with the University of Nevada )
USDA policy proh ibits discrim ination because of race, co lor. natio nal orig in, sex. age, religion. or handicapping condrtion .Any person who believes he Of she has been discriminated against in any USDA-re lated activity should immediately contact theSecretary 01Agricu lture, Washington, DC 20250.
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CONTENTSPage
Introduchon .•....•••..••....•....................•..........•...••..........•••..•....1Background ..••.._.••........••...••...••..•••..•. ...•...........................1Object ive __ 1Bas is of Handbook ..........•....•..•.....•...••..•••..•...•...•...•......... 1Scope 01Handbook .............••.....•.....••..••...••.........__ 2Handbook Organization ..•. ..•••.••........................•..•••..•....•.2Units ••..••...•.••...••...••..••.••...••..••..•.•......•....•..•••..•.•••..••...••..•.2
Part 1. Basic Considerat ions 3
Chapter 1. Stat ions; Station Networks ••..••...••..••.••.••.•..•••..•..31.1 Purposes of Station Data ..••....................•.••••..•••••..•.•.31.2 Representativeness ••..•••..••..•.•.......................••••••..••..3
Comparability 01 Station Data •.......•.....•••.•.•..•..•..••..•.••. 31.3 Network Designs ••.•••...............•.•.•••••..•••....•••..••...••.....3
Objective Method s 3Present Status; Sugge stions 4
Chapter 2. Station Types; Siting ••..•..............••.•..••...••...••..... 42.1 Manual·Type Weather Stations.................•...••..••••.•••.42.2 Manual Flre-weetrer Stations ..••..•.•...................••..... 4
Instrumental Equipment .•.•..••••..•....••..••.......................4Observations and Transmission of Data; AFFIRMS ••.5limitations •...••...............••....•..•.................................... 5
2.3 RAWS and Other Automatic-Type Stations ...•...•.......52.4 Othe r Station Configu rat ions ..••.•.......•.•..•.•...•...•.........52.5 Site Select ion Standards ...•..•.•................................... 5
Chapter 3. Ge neral Requirements of Equipment 63.1 Characteristics of Instruments 6
Desirable Characte rist ics •.............. .............•............ .•.6Reco rding Instruments .•..•...•.........•.•.•............•..•.........6
3.2 Accuracy Standards ..••.......•.....•...••............................ 6Manual-Type Equipment ............•..... ................•.......... 7RAWS Equipment ....... ...•••.................••....................... 7
Chapter 4. Responsibilities 74.1 Installation and Maintenance 74.2 Observer Requirements 74.3 Management 8
Chapter 5. Data Management 85.1 Storage of Retrieved RAWS Data 85.2 Archiving of Data 85.3 Quality Control .............•... ........ ..........•............•.......... 85.4 Data Display and Use ...•............................................9
Display of f ire·Weather Data 9Computer Programs Using Archived Data 9
Part 2A. Manual Weather Stat ions: Measurements;Instruments .........•........•............................................••...•.. 11
Chapter 6. Stand ard Equipment List .......•.••.......•....••.........1t6.1 Manual Fire-Weather Staton 116.2 Evaporat ion Station •..............•..•••..••...............•...•..... 116.3 Climatological Station.•..•...........••...••.•.................••..•11
Chapter 7. Temperature and Humidity ..•.••...••......•.......•....• 127.1 Temperature ••....••.••...••..•••..••..............•••..•.•.•••.....•.... 127.2 Relative Humidity and Dewpoint •.••.•....•..•...••........... 12
Use of Psychrometric Tables •.••..•••..•...........•...........•127.3 Instrument Shelters •.••••...••..•••...•...•.•••......................12
ccrtcn Region Shelter 13Solar Radiation Shields ••........•..•••..•..•..••.•..•. ...••••...... 13Portable Shelters ••.........•..••............................••..•...... 14
Page7.4 Liquid-in-Glass Thermometers 15
Standard Maximum and Minimum Thermometers 15Six's (Comb ined) Maximum and Minimum
Thermometer 167.5 Other Thermometers 17
Bourdon and Bimetal Thermometers 17Electr icallElecl:ronic Thermometers 18
7.6 Psychrometers 18Standard Electric Fan Psychrometer 18Hand Fan Psyd'lrometer 19Portable Eleetric Fan Psychrometer 19Sling Psychrometer 20Mason (or Mason's) Hygrometer 22Mortarboard Psychrometer 22
7.7 Hygrothermographs 23The Temperature Element 23The Relative Humidity Element 23The Chart Record 24Reliability 26
Chapter 8. Wind 268.1 Wlndspeed Instruments 268.2 Contading Anemometers; Readout Devces 2u
Anemometers Equipped With 'I_ mile Contacts 28Mechanical Counters 28Anemometers Equipped With t -mue Contacts 30The Hygrothermoaerograph 31Anemometers With Self-Contained Readout 31
8.3 Generator Anemometers 31Accumulating Generator Anemometers 32
8.4 Hand·Held Anemometers 33Dwyer Hand·Held Wind Meter 34
8.5 Wind Direction Indicators 35Wind Vanes 35
Chapter 9. Precipitation 369.1 Nonreoording Gauges 36
Standard 8· inch Rain Gauge 36Small.Qrrtice Rain Gauges 37
9.2 Recording Precipitation Gauges 39Universal Weighing Gauge 39Punched-Tape Recorder 41Tipping Bucket Gauge 42Reliability of Recording Rain Gauges 44
9.3 Storage Precipitation Gauges 44Types 01Storage Gauges 44
9.4 Wind Shields 459.5 Snowfall and Snow Depth Indicators 46
Snowlall 46Snow Depth 47
9.6 Supplemental Information 47Kind 01Precipitation 47Time Precipitation Began and Ended 47Durat ion 47
Chapte r 10. Fuel Moisture 4810.1 Fuel Moisture Sticks 4B
Standard Fuel Moisture Stick .4B10.2 Fuel f&listure Scales 4B
The Forester Fuel Moisture Scale 48Forester Pon able Fuel Moisture Scale 49Williams Pocket Firest ick Moisture SCale .49Triple Beam and Harvard Balances 49
PageChapter 11. Clouds. Sun shine. and Sola r Radiation ••.......52
11.1 Clouds .....................••..•.............•.•..•....•...•••.•...••..••.52Cloud Forms .•..••..•...•..........••................................•....52Cloud Cover .•..•..••..............•........•.............................52
11.2 Sunsh ine and Solar Radiation Instruments 52Sunshine Duration Recorders 52Pyranometers ..................................•..•....••..•••....•••..•.52
Chapter 12. Evaporation 5412.1 Evaporation Pans 5412.2 Evaporat ion Stat ion Equipment 54
Class A Evaporation Pan and Accessories 54Supplemental Instruments 56
Chapter 13. So~ Temperature 5713.1 Instruments 57
Mercury-in·Steel Thermometers 57l iquid·in-Glass Thermometers 57Thermometer Head Shelter 58
13.2 Measurement Depths 58Chapter 14. Soil Moisture 58
14.1 Measurement Methods 58Electrical Resistance Method 58Neutron Method 59
Part 28. Manual Weather Stat ions: Installation andExposure of Equipment 61
Chapte r 15. Standard Weather Stations 6115.1 Standard Fire·Weather Station 61
l ocation 61l ayout
15.2 Standard Evaporation Station 61l ocation 61Layout 62
Chapter 16. Temperat ure and Humidrty Equipment 6316.1 Instrument Shetter 63
Cotton Region Shetter 6316.2 Maximum and Minimum Thermometers 65
Standard liquid-in-Glass Thermometers 65Other Maximum·Minimum Thermometers............•....65
16.3 Psychrometers 65Standard Electr ic Fan Psychrometer 65Other Psychrometers 65
16.4 Hygrothermograph 65Chapte r 17. Wind Equipment 66
7.1 Anemometers 66Height Adjustment 66Installation 67Lightning Protect ion 70
17.2 Wind Counters 71Location 71Installation 71
17.3 Indicator Dials and Chart Recorders ...•...••..••...•. ...•7117.4 Wind Vanes 71
Location 71Installation 72
Chapter 18. Precipitation Equipment 7318.1 Exposure Guidelines 7318.2 Precipitation Ga uges 73
Standard 8· inch Gauge 73Universal Weighing Gauge 73
Page18.3 Wind Shields 1418.4 Snow Stakes 74
Chapter 19. Fuel Moisture Equipment 7419.1 Fuel Moisture Sticks 74
Duff Bad 74Stick Exposure 75
19.2 Fuel Moisture Scales 75Forester Scale 75
Chapter 20. Pyranometers and Sunshine Recorders ..•••.•. n20.1 Exposure n20.2 Installation n
Pyraoometers nCampbelJ.Stokes Sunshine Record er n
Chapte r 21. Evaporation Station Equipment n21.1 Class A Evaporation Pan n
Stilling Well 7721.2 Supp!ementallnstruments n
Precipitation Gauge nTotalizing Anemometer nWater Temperature Thermometer n
Chapter 22. Soil Tempera ture and Moisture Instruments .. 7822.1 Soil Thermomet ers 78
location of Soil Plot .................. ............ ....•.......•....... 78Installation of Thermometers 78Thermometer Head Sheller 78
22.2 Soil Moisture Meters 80Site Selection 80Electrical Resistance MeIers 80Neutron Probe 80
Part 2C. Manual Weather Stations: ObservationalProcedure s 81
Chapter 23 . Temperature and Humidity 8123.1 Thermometers 81
Reading Thermometers, General Precautions ..•....•..8123.2 Maximum and Minimum Thermometers ••..••...•...•••81
Standard liquid-in-Glass Thermometers 81Six's Thermometer 82Other Thermometers 82Recording 01 Maximum and MinimumTemperatures 82
23.3 Psychrometers 83General Operating Instructions 83
23.4 Psychrometers. Specif ic Types 84Standard Electric Fan Psychrometer 84Hand Fan Psychrometer 84Portable Electric: Fan Psychrometer 84Sling Psychrometer 85Mason Hygrometer 85Mortarboard Psychromeler 85
23.5 Hygrolhennographs 86Changing the Chart 86Inking the Pens 86Checking the Cal ibration 86
Chapter 24. Wind 8724.1 Average WlOdspeed 87
Contacting Anemometers. With '/-m~e Contacts 87Anemometers With Self-Contained Readout 87Generator Anemometers 88Hand-Hejd Anemometers 88
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Page24.2 Correcti ng Windspeeds Observed at Heights
Above or Be low the 20-ft Standa rd 89Winds Observed Above Standard Height 89Winds Observed Below Standa rd Height ..........•....... 89
24.3 Est imating Windspe.ed From Beaufort Scale 9024.4 Wind Gusts; Peak Speed s ...•............... ....... ........... 91
Chapter 25. Precipitation _...•.................... ..............9225.1 Nonrecording Gauges ..................•......................... 92
Timely Measurement of Precipitation .....................••. 92Standard a-inch Gauges 92Sma ll.Qrifice Ga uges ........... .•........•..........................93
25.2 Recording Gauges 93Universal Weig hing Gauge .......................•................93Punched Tape Recorder ..... ......................•...............95Tipping Bucket Gauge 95
25.3 Storage Gauge s .................................•... ............ .... 96Weighing Procedure 96
25.4 Measurement of Sno wfall and Snow Depth 96Snowfall •..•....•.............................•..............................96Snow Deplh ......... .......... ...... ..........•.........•................. 97
Chapte r 26. Fuel Moisture 9726.1 Use 01Fuel Moisture Beales 97
Forester (Appalachian) Scale 97Forester (Chishol m) Portable Scale .......•.................. 99Williams Pocket Sca le ....... ......... ............•...............•.. 99Triple Beam Balance 100Harvard Balance ......•.....•............................. ............ 100
Chapter 27. Evaccretcn Station Measurements 10227.1 Evaporation 102
Use of the Hook Gauge 102Use of the Fixed Point Gaug e 103
27.2 Supplemental Data 103Wind Movement .....................................•................ t03Maximum and Minimum Water Temperatures 103
Chapter 28. Soil Temperature 10328.1 Req uired Observations 103
Read ing The rmometers 103
Part 20. Man ual Weather Stat ions: Maintenance 105
Chaple r 29. General Maintenance Principles 10529.1 Bas ic Ma intenance Prog ram 10529.2 Maintena nce Equipment 105
Station Too l Cache ...•......•................... ..... ............... 105Workbench Items 105
Chapter 30. Temperature and Humidity Equipment 10630.1 Instrument Shetters .....•...................•.................... 106
ccncoReg ion Shetter _ 10630.2 Thermometers and Psychrometers •..................... 106
Cleaning _ _ 106Resto ring Worn Markings 106Thermometer Defects 106Rejoining Separated COlumns 107
30.3 Maximum and Minimum Thermometers l07Standard Thermometers Wrth Townsend Support .. 107Six's Thermomete r 109
30.4 Psychrometers 110Dry- and Wet-Bulb Thermometers 110The Wet-Bulb WICk 110Standard Elect ric Fan Psychrometer 111Hand Fan Psychrometer 112
PagePortable Elect ric Fan Psychrometer 113Sling Psychro meters 114Mortarboard Psychrometer 1t 5
30.5 Hygrothermographs 115Cleaning _ 116Pen Arm Assemblies 116Chart Drive Assembly 118Clock _ _118Bartery -Pcwered Chart Drive 119Calibration 119Zero Adjustment 120Range Adjustment 120
Chapter 31. Wind Equipment t 2231.1 General Maintenance of Cont act ing
Anemo meters 122Cleaning 122Lubrication 122Mechanica l Inspect ion and Recalibration 122Circuit Check 123
31.2 Details fo r Specific Anemometer s 124Forester No. 9X140 Anemometer 124Forester Pvtodel 9X15 0 125Small Airways-Type Anemo meter 126Ste wart Aluminum Cup Anemometer .._ 128Beffert Totalizing Anemometer 129Friez Dial-Type. Anemometer 130WeatherM easure W164 and W l 64B Contacting
Anemometers 132Natural Power Anemometer. Models A19, A21,
and A22 133Dwyer Wind Meter 133
31.3 Wind Counters 134Buzzers and Flashers 134Forester 9X156 Wind Counter 135Forester (Haytronics) Tota lizing Wind Counte r 136Stewart Electron ic Odometer 136
31.4 Wind Vanes 137Stewart Wind Direction System 137
31.5 Other Windspeed and Direction Systems 139Chapter 32. Precipitation Gauges 139
32.1 Nonrecording Rain Ga uges 139Standard 8·inch (and Othe r) Nonrecording
Gauges 13932.2 Recording Rain Gauges 139
Universal Weighing Gauge 139Tipping Bucket Gauge 141
Chapter 33. Fuel Moisture Equipment 14233.1 Fuel Moisture Sticks _ 14233.2 Fuel Moisture Sca les 142
The Forester Sca le 142Region 6 Scale 143Forester (Chisholm) Portable Scale 143Wi lliams Pocke t Sca le ._ 143Triple Bea m Balance 144Harvard Balance _ 144
Chapter 34. Pyranomete rs and Sunshine Recorde rs 14634.1 General Maintenance 146
Chapter 35. Evaporat ion Station Equ ipment.. 14635.1 Evaporation Pan and Access or ies 146
Evecoratc n Pan 146Stilling Well and Gauge _ 146
Page35.2 Supplemental Instruments 146
TOlalizing Anemometer 146Six's wat er Thermomeler 146
Chapter 36. Soil TemperaturelSoHMoisture Plot andEquipment 147
36.1 Maintenance of Soil Plot 14736.2 Soil Thermometers 14736.3 Soil Moisture Melers 147
Part 3. Automatic Weather Stations (AWS) and RemoteAutomatic Weather Stations (RAWS) 149
Chapter 37. General Features of Automatic and RemoteAutomatic Stat ions 149
37.1 cn arecteretcs of Stations 149Applications 149
37.2 Sensors 14937.3 Data Processing and Storage 15037.4 Data Retrieval 150
Chapter 38. Description of RAWS SystemComponents .. 15138.1 Sensors 151
Windspeed 151Wind Direction 151Air Tempe rature ,..", ,.., 151Relative Humidity , 151Precipital ion 151Fuel Temper ature 152Fuel Moisture 152Soil Temperature and Soil Moisture 152Solar Radiation 152Baromet ric Press ure 152Visibilily 152Batlery Voltage 152
38.2 Accesso ries 152Tower Assembly 152Solar Panel; Batteries 153
38.3 Syste m Electro nics 153Data Collection Platform 153
38.4 Commu nications 153Satellile COmmunical ion 153O!:herCommunicat ions Options 153
38.5 Portable Remote Automatic Weather Stations 154c hapter 39. Classes 01 RAWS Deployment 155
39.1 Classification 155Class I 155Class II 155Class III 155Class IV 155
39.2 Configurations by Class , 155Class I (Permanent Sites) 155Class II (Fire Weather. Semipermanent Siles) 156Classes III and IV (Temporary Siles ) 156
Chapter 40. Installation Procedures. Standa rd RAWSSystems , 156
40.1 lnstauetc n Considerations 15640.2 The Tripod Tower Installation 156
Wind SpeedlW'ind Direction Crossarm Assembly 157Wind Direction Sensor 157Windspeed Sensor 157Solar Panel 157Tipping Buckel Rain Gauge , 157
PageAir Tempereturezaereuve Humidily Sensor 158Fuel Temperatu re Sensor 158Soil MoislurelSoil Temperature Sensor 158Barometric Pressure Sensor 158Antenna 158Data Collection Platform 158
40.3 Rohn Tower Installation 158Chapter 41. RAWS Sensor Standards 159
41.1 Sensor Standards (Tripod Tower Installation) 15941.2 Transmitted Sensor Data 160
Chapter 42. Schedu led RAWS Maintenance 16042.1 Preventive (Field) Maintenance: Outline of
Schedu le 160Schedule by Station Class 160
42.2 Preventive Maintenance by BlM Field s ucccnGroup 160
Field Equipment and Requirements t60Visual and Physical Inspections 161Electronics Inspection 161
42.3 Depot Repair Facility-Maintenance. Calibrat ion.and Repair 162Test Equipment 162Depot Preventive Maintenance Slandards 162Depot Sensor Overhaul Standards 163
Chapter 43. Breakdown RAWS Maintenance 16343.1 Del inition; Monitoring 163
Performance Monitoring Specil ications 163Data Monitoring 164
43.2 Field Work 165Chapter 44. Automatic Weather Stations. Non·RAWS 165
44.1 Data Collect ion and Transmission 16544.2 Sensors 170
Windspeed and Wind Direction 170Temperature and Humidity 172Precipitat ion 173Solar Radiation 173Barometric Pressure t 74
References t 75
Append ix 1. Abridged Observational Instructions fo rManual Fite·Weafher Stations 178
Appendix 2. Psychrometric Tables 183Append ix 3. Cloud Classilicat ion and Identification 203Appendix 4. Equipment Installation and Maintenance
Checkl ists lor Manual Fire·Weather Statcns 212Appendix 5. Detailed Spectcenon Drawings for
Miscellaneous Items at Manual Fee-weatherStations 215
Append ix 6. User Instructions for RetrievingRAWS Data 221
Append ix 7. Equipment Sources; Manufacturers andSuppliers 223
Append ix 8. Conversion of Measurement Units-Formulas. Examples. and Condensed Tables 226
Append ix 9. Abbrev iations and Acronyms 231
Index 232
INTRODUCTION
BackgroundThe u.s. Department of Agriculture (USDA), Forest
SE-rvice IFS), the U.S. Department of th e In te rio r (DSOn,Bureau of Land Management (BLM). and the USDI National Park Service (NPS) sha n> common objectives in themanagement of natural rescurees. Likewise, they areoften faced with the sam e need for eeeure ee an d timelyweather data. These data are vital to many operationaland program decisions. Most of the required da ta mustcome from the agencies' own wea ther stations. Th e totalnumbe r of these stations is rather large. As of 1988, theFS ope rated approximately 1,000 manual and 265 automatic-type stations; t he BL~f, more than 165 automa ticstations. The NPS maintains a skeleton network ormanuaI and automatic stations. The US DI Bureau of IndianAffairs (BlA) and various State and pri vate agencies ororganizations a lso req uire ......ather data and ope ratewea ther stations.
Tht" da ta collec ted from th ese stations ar e used for ava riety of pcrpceee. The primary use has been for S aricnal Fi re Danger Rating System (S FDRS) calculations.But resource management now commands a major shareof use in som e a reas, pa rticularly whE're automatic stations a re operated year-rou nd (for example, in theSiskiyou :-';ational Forest in Oregon). Wea ther recordshave a ke y role in fire planning efforts. and the S FD RSou tputs (indexes ) a re sensitive to inaccuracies in the acquired wea ther data. Thus. if the historical or currentfire wenther data contain errors (or values from poorlysited or expose d instruments), fire management plans andoperational guidance derived from such data can be seriously a ffected.
Although each agency has its o.....n network of .....eatherstations. t hese net .....orks a re often maintained throughcooperative inte ra gency efforts. ThE' data gathered bythe diffe rent age ncy net.....orks are also shared among theagencies through a common data base and communications medi um .
Curren tly , the Admin is tra tive Forest Fi re Infor ma tionRetrie val and Ma nagement System (AFFIR ~(S) is thecomm on medi um for forestry .....eather data management.AFFIR~IS wa s design ed in the 1970's to address primnrily fire wenthe r data requ iremen ts identified at that time .Additiona l weather data needs ha ve subsequently beeniden tified . '-tany of thes@arenotfir e relatffiandare notbE-ing addressed by AFFIR~IS. A comprehensive Wea therInform a tion Mana geme nt. System (WI~tS) is thereforebeing developed to meet cu rrent needs. \\l~tS is expectedto be available for in itial testing in 1990 and to becomecperurional in J a nua T)' 1992 .
In a n effor t to standardize and improve data acquisitionpractices. and ultimately promote h igh data quality. aninteragency committee re pre senti ng the BL~I . FS . a ndNPS .....as formed to oversee the join t publication of a ninte ragency wea ther station handbook. The committeefirst met in BoiSE', 10, in Jul~.. 1987 , wi th the followingmembers prese nt: Buddy Adams (BL~f), John Bo.....dler(S PS). William C. Fischer <FSJ. Russe ll A. Gri pp (FS),Donald A. Haines (FSl, Ph ill ip F. Sielaff (BL~Il, Roger A.
Tu cker (FS). and J ohn R. Warren (FS). The me mbersdeveloped plans and gu idelines tha t ha ve led to the present handbook. Although weather s ta tion requirementsma y vary be tween agencies or within n given regi on, for.est , pa rk . or district, certain basic requiremen ts are common to all ju risdictions.
ObjectiveThe ove rall pu rpose ofthi!l handbook is to ai d personnel
of th e Burea u of Land ~Ianagemen t, Forest Service. a ndNational Park Service-and other Federal. State, andprivate wildla nd resource agencies-in obtaini ng needed,reliable wea ther data. Such data must be a ccu ra te complete. represen ta tive. and comparable between stations.Toward t his. the handbook offer s certain standards andprocedures desig~d to minim ize sources of error a ndother prob lems affecting Il.'ea ther data. Specific attentionis given to instrumental equipment-and its siting, insta llation, and mai ntenance-and operating (observ a tional)practices.
Concurrently, this handbook also has the purpose ofprovidi ng a re ference that meets the requirements of eachagency, thereby avoidi ng duplicatio n of publication e f_forts among the age ncies.
Basis of Handhook
This handbook is la rge ly a revi sed , u pda ted version ofthe Fire-Weather Obse rvers' Handbook by Fischer andHardy (19 76), wi th expanded content in cluding un .manned, automated ('"a utoma tic") weathe r stations . DEotails conce rning remote automatic weather stations a re inlarge par t based on a BL~l manual (CSDI BL~l . RAWSSupport Facility 1987). The BD 1 manual, revi sed byRobert ~tcCormick and Bu ddy Adams, was ....-rittenmainly by Ph illip F. Sielatf in 1984. The content of thepresent handbook provides for a broad range ofapplica tions. The standards nn d procedure s presented here areconsistent with well -establi shed practices of metecrologt cal organizations. hydrologica l se rvices, and fire con trolagencies. P ublica tions b)' the U.S. Department or Camme rce (19 72) a nd t he World ~1etf'orological Organization(l983) were am ong the pri mary! contributing sources.
In addition to the material obt.ained from pu blica tions,updated information was furn ished b)' several in dividu.als. These contributors. all a ffiliated ....ith the ForestService. include: Ru ssell A. Gri pp, Siskiyou XutiennlFore !lt. Dona ld A, Haines. Xorth Cen tral Forest EXJX' rimen t Station, and J oh n R. Wa rre n . Fire and Avi a tion~Ianagement, a t Boise. 10, Bonnie :\lnson. Wa tershedand Air ~tanagt'ment, Washington, DC. contributed tothe Introduct ion. Co talogs or litermu re from various companies provided infonnation describing wea ther-sta tionequipment.
Fig-un> Crf'dits- Cnless otherwise credi ted in thecaptions. ph otographs and oth er figures in this handbookare from the LSDA Forest Service . ~1ost of t he Fore stServiee photos a nd drav,i nss are derived from Fische r andHa rdy (19 76); citations are given in the case of other For.est Sen.ice publica tions .
Scope of Han dbookTh is handbook is meant to be a comprehensive refer
ence, although it cannot be all-i nclusive-c-particularlyon details concerning technically complex OT speciali zedequipment and systems. The discussions of station siting,instruments, and related standards pertain to manualand automatic w ea ther stati ons oper a ted for a varietyof resource ma nagem ent, monitoring, and research purposi'S . This should be understood despite the predominant refe rence to fire -weather stations.
The observational equ ipment discussed is that currently in use , or available for use, a t wea ther stationsopera ted by United Stattos government agencif's . Muchof the the manual, direct-reading equipment is the standard Nationnl w ea ther Service or Forest Service type: bu tsu itable, less expensive or more convenient alternativetypes or models are included for consid@ration . Thesealternative s include n@w@rinstrum@nts incorporatingelectronic fea tures and digital readout. Conversely, someofth@modelsdiscussedhere,particularlyforwi ndspeedmeasurement, may no longer be manufactured but arestill in use, Such models, if incl uded in the handbook b)'Fischer an d Hardy (19 76), ere retained in the presenthandbook.
Because of the nature and variety of ma nua l instruments, which can be operated and maintained by non specialists a fter rel atively simple in struction, the ir coveragein this handbook is much l@ngthipr than that ofthe automa tic equipment. Correspondi ng ins tructions pertain ingto automatic equipment are, largely, left to operating andservice manuals provided by the manufacturers.
Handbook OrganizationTh is handbook is organized into three main parts, each
containing chapters wh ose numbering seq uence continuesfrom one pa rt to a nother.
2
Part 1 discusses basic considerations that apply to bot hma nual and a utomatic wea ther stations. The top ics include station networks, site selection standards, equipm@ntrequirements,and datamanagem@nt. Part 2 pertains to manual stations, ....-jth four subdivisions (A, B, C,and 0 , respectively) describing the various weather instruments, their installation, obsEorvstional proce dures,a nd maintenance . This separation , used by Fischer andHardy 1976, .....as adopted as a convenient and logical wayof presenting the Iarge amou nt of material to users. Inmany cases, separate individuals a rt' involved in the installation, observing; and maintenance tasks. Numerousfigures (mostly photograph s) a re included for illustrationand easy reference. Part 3 discusses automatic station&,with details focused mainly on remote automatic wea therstations (RAWS).
The handbook contains several appendices. These in clude an abridged st>tof observational instructions formanual stations, psychrometric tables, a fire- weatherstation maintenance checklist, user instructions for re t rieving RAWS data via computer terminal , and a list ofequipment manufacturers or suppliers. An index of BUbjeer metter is also included.
Unit sWith a few customary excep tions (a s in chapter 10 ),
the measurement un its given her. are thOSol' in theEnglish system. English units remain in predominantuse for surface weather observations in the United States.M. tric equivalents can be obtained from con version formulas in a ppendix 8.