U .S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: Aviation Weather Services Date: 11/14/16 AC No: 00-45H Initiated by: AFS-400 Change:
The Federal Aviation Administration (FAA) publishes Advisory Circular (AC) 00-45, Aviation Weather Services. This publication supplements its companion manual, the current edition of AC 00-6, Aviation Weather, which documents weather theory and its application to aviation.
Revision H of AC 00-45 (AC 00-45H) provides an improved organization of aviation weather information. The document is organized using the FAA’s three distinct types of weather information: observations, analyses, and forecasts. Within this construct, AC 00-45H explains U.S. aviation weather products and services. It provides details when necessary for interpretation and to aid usage.
In the past decade, access to aviation weather products has greatly improved with the increase of flight planning services and weather Web sites. The experience of listening to a weather briefing over a phone while trying to write down pertinent weather information becomes less tolerable when the reports are easily obtainable on a home computer, tablet computer, or even a smart phone. To see weather along your route using a graphic of plotted weather reports combined with radar and satellite is preferable to trying to mentally visualize a picture from verbalized reports.
Although most of the traditional weather products, which rolled off the teletype and facsimile machines decades ago, are still available, some are being phased out by the National Weather Service (NWS) in favor of new, Web-based weather information.
It is the objective of AC 00-45H to bring the pilot and operator up to date on new and evolving weather information and capabilities to help plan a safe and efficient flight, while also describing the traditional weather products that remain.
Online aviation weather information is easy to access, and so are references explaining the information. That is why AC 00-45H contains fewer illustrations and less detail for products available online. This AC will give an overview and direct the pilot where to find more weather information and explanatory details. Product examples and explanations are taken primarily from the National Oceanic and Atmospheric Administration (NOAA) NWS Aviation Weather Center’s (AWC) Web site (http://www.aviationweather.gov) and other pertinent NWS Web sites.
Due to the fluid nature of Web addresses, this AC minimizes the inclusion of Web site links.
Instead, it provides the name of the Web site which can be easily found using Internet search tools.
11/14/16 Aviation Weather Services AC 00-45H ii An online version of this document (including digital images) can be found at http://rgl.faa.gov/.
AC 00-45H cancels AC 00-45G, Change 2, published October 2014.
If you have suggestions for improving this AC, you may use the Advisory Circular Feedback Form at the end of this AC.
ORIGINAL SIGNED by /s/ John S. Duncan Director, Flight Standards Service
11/14/16 Aviation Weather Services AC 00-45H iii
CONTENTS Paragraph Page
Chapter 1. Aviation Weather Service Program1-1
1.1 National Oceanic and Atmospheric Administration (NOAA)1-1
1.1.1 National Environmental Satellite, Data, and Information Service
(NESDIS)1-1
1.1.2 National Weather Service (NWS)1-1
1.2 Federal Aviation Administration (FAA)1-4
1.2.1 Air Traffic Control Systems Command Center (ATCSCC)1-4
1.2.2 Air Route Traffic Control Center (ARTCC)1-4
1.2.3 Airport Traffic Control Tower (ATCT) and Terminal Radar Approach
Control (TRACON)1-5
1.2.4 Flight Service Station (FSS)1-5
1.3 Dissemination of Aviation Weather Products1-5
1.3.1 Weather Briefings1-6
1.3.2 Pilot Briefing via the Internet1-8
1.3.3 Telephone Information Briefing Service (TIBS)1-8
1.3.4 Hazardous In-flight Weather Advisory Service (HIWAS)1-9
1.3.5 Flight Information Service-Broadcast (FIS-B)1-10
1.3.6 Operational Use of FIS-B Products1-13
Chapter 2. Aviation Weather Product Policy2-1
2.1 Use of Aviation Weather Products2-1
2.2 Types of Aviation Weather Information2-1
2.2.1 Observations2-1
2.2.2 Analyses2-1
2.2.3 Forecasts2-2
2.3 Categorizing Aviation Weather Sources2-2
2.3.1 Federal Government2-2
2.3.2 Commercial Weather Information Providers2-2
Chapter 3. Observations3-1
3.1 Aviation Routine Weather Reports (METAR) and Special Weather Reports
(SPECI)3-1
3.1.1 Aviation Routine Weather Report (METAR)3-1
11/14/16 Aviation Weather Services AC 00-45H iv
3.1.2 Special Weather Report (SPECI)3-1
3.1.3 General Types of Observations3-3
3.1.4 Recency of Observed Elements at Automated Stations3-3
3.1.5 Format3-4
3.2 Aircraft Observations and Reports3-26
3.2.1 Pilot Weather Report (PIREP)3-26
3.2.2 Air-Reports (AIREP)3-36
3.3 Radar Observations3-37
3.3.1 Description3-37
3.3.2 Issuance3-37
3.3.3 Modes of Operation3-39
3.3.4 Echo Intensities3-40
3.3.5 Radar Products3-41
3.3.6 Precipitation3-48
3.3.7 Limitations3-50
3.3.8 Use3-56
3.3.9 Future Products3-56
3.4 Satellite3-57
3.4.1 Description3-57
3.4.2 Imagery Types3-57
3.5 Upper-Air Observations3-62
3.5.1 Radiosonde Observations3-62
3.6 Graphical Depiction of Surface Observations3-63
3.6.1 AAWU Surface Observations3-63
3.6.2 METARs on Aviationweather.gov3-69
3.7 Aviation Weather Cameras3-74
3.7.1 FAA Aviation Weather Cameras3-74
3.7.2 Issuance3-74
3.7.3 Use3-76
Chapter 4. Analysis4-1
4.1 Surface Analysis Charts4-1
4.1.1 WPC Surface Analysis Charts4-2
11/14/16 Aviation Weather Services AC 00-45H v
4.1.2 Unified Surface Analysis Chart4-11
4.1.3 AAWU Surface Chart4-12
4.2 Ceiling and Visibility4-13
4.2.1 Ceiling and Visibility Analysis (CVA)4-13
4.2.2 Weather Depiction Chart4-19
4.3 Upper-Air Analyses4-20
4.3.1 Issuance4-20
4.3.2 Radiosonde Observation Analysis4-23
Chapter 5. Forecasts5-1
5.1 Significant Meteorological Information (SIGMET)5-1
5.1.1 SIGMET Issuance5-1
5.1.2 SIGMET Standardization5-4
5.1.3 SIGMET (Non-Convective)—CONUS5-4
5.1.4 Convective SIGMET5-7
5.1.5 SIGMET—Outside the CONUS5-10
5.2 Airmen’s Meteorological Information (AIRMET)5-16
5.2.1 AIRMET Issuance5-17
5.2.2 AIRMET Issuance Criteria5-19
5.2.3 AIRMET Standardization5-19
5.2.4 AIRMET Bulletins, Issuance Times, and Valid Period5-20
5.2.5 AIRMET Format and Example5-20
5.3 Graphical Airman’s Meteorological Advisory (G-AIRMET)5-23
5.3.1 G- AIRMET Issuance5-24
5.3.2 G-AIRMET Content5-24
5.3.3 Use5-30
5.4 Center Weather Advisory (CWA)5-30
5.4.1 CWA Issuance5-30
5.4.2 CWA Criteria5-31
5.4.3 CWA Format and Example5-32
5.5 Meteorological Impact Statement (MIS)5-33
5.5.1 Valid Period5-34
5.5.2 Content5-34
11/14/16 Aviation Weather Services AC 00-45H vi
5.5.3 Format5-34
5.6 Additional Products for Convection5-35
5.6.1 Convective Outlooks (AC)5-35
5.6.2 Watch Notification Messages5-38
5.6.3 Collaborative Decision Making (CDM) Collaborative Convective
Forecast Planning (CCFP) Guidance5-46
5.6.4 Extended Convective Forecast Product (ECFP)5-50
5.6.5 National Convective Weather Forecast (NCWF)5-51
5.7 Products for Tropical Cyclones5-56
5.7.1 Tropical Cyclone Advisory (TCA)5-56
5.8 Volcanic Ash Forecasts5-58
5.8.1 Volcanic Ash Advisory Center (VAAC)5-58
5.8.2 Volcanic Ash Advisory (VAA)5-59
5.9 Area Forecasts (FA)5-61
5.9.1 FA—Gulf of Mexico, Caribbean, and Alaska5-61
5.10 Alaskan Graphical Area Forecasts (FA)5-70
5.10.1 Issuance5-70
5.10.2 Content5-71
5.10.3 Use5-75
5.11 Terminal Aerodrome Forecast (TAF)5-75
5.11.1 Responsibility5-75
5.11.2 Generic Format of the Forecast Text of an NWS-Prepared TAF5-76
5.11.3 Issuance5-92
5.12 Route Forecasts (ROFOR)5-94
5.12.1 Issuance5-94
5.12.2 ROFOR Amendments5-94
5.12.3 ROFOR Corrections5-94
5.12.4 ROFOR Content5-95
5.12.5 Example5-95
5.13 Wind and Temperature Aloft5-96
5.13.1 Wind and Temperature Aloft Forecast (FB)5-96
5.14 Freezing-Level Graphics5-100
5.14.1 Issuance5-101
11/14/16 Aviation Weather Services AC 00-45H vii
5.14.2 Format5-101
5.14.3 Use5-101
5.15 Upper-Air Forecasts5-102
5.15.1 Constant Pressure Levels Forecasts5-103
5.16 Short-Range Surface Prognostic (Prog) Charts5-105
5.16.1 Content5-106
5.16.2 Issuance5-108
5.16.3 Use5-108
5.17 Significant Weather (SIGWX) Forecast5-108
5.17.1 Low-Level Significant Weather (SIGWX) Charts5-108
5.17.2 Mid-Level Significant Weather (SIGWX) Chart5-114
5.17.3 High-Level Significant Weather (SIGWX) Charts5-116
5.17.4 Alaska Significant Weather (SIGWX) Charts5-122
5.18 World Area Forecast System (WAFS)5-124
5.18.1 WAFS Forecasts5-124
5.19 Additional Products for Icing and Turbulence5-133
5.19.1 Current and F orecast Icing Products (CIP/FIP)5-133
5.19.2 Graphical Turbulence Guidance (GTG)5-142
5.20 Additional Products for Clouds, Visibility, Weather, and Surface Wind
Forecasts5-147
5.20.1 NWS Aviation Forecast Discussion5-147
5.20.2 NWS National Digital Forecast Database Graphic Products5-149
5.20.3 Cloud Top Heights Product5-160
5.20.4 Cloud Layer Product5-162
5.21 Airport Weather Warning (AWW)5-162
5.21.1 Issuance5-162
5.21.2 Airport Weather Warning (AWW) Format and Example5-163
5.21.3 Use5-163
5.22 Space Weather5-163
5.22.1 NOAA Space Weather Scales5-163
5.22.2 Space Weather Products5-164
5.23 Use5-169
5.24 Soaring Forecast5-170
11/14/16 Aviation Weather Services AC 00-45H viii
5.24.1 Issuance5-170
5.24.2 Content and Format5-170
5.24.3 Example5-170
Chapter 6. Aviation Weather Tools6-1
6.1 Helicopter Emergency Medical Services (HEMS) Tool6-1
6.1.1 Availability6-1
6.1.2 Content6-1
6.1.3 Strengths and Limitations6-13
6.1.4 Use6-14
6.2 Flight Path Tool6-14
6.2.1 Description6-14
6.2.2 Access6-15
6.2.3 Use6-15
Appendix A. Definition of Common Terms Used in En Route Forecasts and AdvisoriesA-1
Appendix B. Standard Conversion ChartB-1
Appendix C. Density Altitude CalculationC-1
Appendix D. Internet LinksD-1
Appendix E. WSR-88D Weather Radar NetworkE-1
Appendix F. Area Forecasts (FA)—Continental United States (CONUS) and HawaiiF-1
FIGURES Number Page
Figure 3-1. METAR/SPECI Coding Format3-4
Figure 3-2. ICAO Continental Codes3-5
Figure 3-3. Obscuration Effects on Slant Range Visibility .................................................................................... 3- 14 F igure 3-4. METAR/SPECI Sky Condition Coding ............................................................................................... 3- 16 Figure 3-5. Pilot Weather Report (PIREP) Coding Format .................................................................................... 3- 27 Figure 3-6. Location of WSR-88D Weather Radar in the CONUS and Their Respective Coverage at 4,000 Feet AGL, 6,000 Feet AGL, and 10,000 Feet AGL ................................................................... 3- 38 Figure 3-7. Location of WSR-88D Weather Radar Outside of the CONUS .......................................................... 3- 39 Figure 3-8. WSR-88D (NEXRAD) Weather Radar Echo Intensity Legend........................................................... 3- 40
Figure 3-9. NWS National Radar Mosaic Example, Which Utilizes NEXRAD Base Reflectivity3-42
Figure 3-10. NWS Regional Radar Mosaic Sector Example, Which Utilizes NEXRAD Base Reflectivity3-43
Figure 3-11. Alaska Radar Mosaic Example .......................................................................................................... 3- 43
Figure 3-12. WSR-88D Weather Radar Composite Reflectivity, Single-Site Product Example3-44
Figure 3-13. Creation of a Composite Reflectivity, Single-Site Product ................................................................ 3- 45
Figure 3-14. Weather Radar 0.5º Base Reflectivity (left) versus Composite Reflectivity (right) Comparison3-45
11/14/16 Aviation Weather Services AC 00-45H ix Figure 3-15. WSR-88D Weather Radar Short-Range (124 NM) Base Reflectivity, Single-Site Product Example ............................................................................................................................................. 3- 46 Figure 3-16. WSR-88D Weather Radar Long-Range (248 NM) Base Reflectivity, Single-Site Product Example ............................................................................................................................................. 3- 47 Figure 3-17. Radar Coded Message (RCM) Display .............................................................................................. 3- 48 Figure 3-18. WSR-88D Weather Radar Convective Precipitation on the 0.5º Base Reflectivity Product Example ............................................................................................................................................. 3- 49 Figure 3-19. WSR-88D Weather Radar Stratiform Precipitation on the 0.5º Base Reflectivity Product Example ............................................................................................................................................. 3- 50 Figure 3-20. Cone of Silence .................................................................................................................................. 3- 51
Figure 3-21. WSR-88D Weather Radar Beam Blockage on Base Reflectivity Product Example3-52
Figure 3-22. WSR-88D Weather Radar Ground Clutter Example .......................................................................... 3- 52 Figure 3-23. WSR-88D Weather Radar Ghost Example ........................................................................................ 3- 53 Figure 3-24. WSR-88D Weather Radar Angel Example ........................................................................................ 3- 54
Figure 3-25. WSR-88D Weather Radar Anomalous Propagation (AP) Example3-55
Figure 3-26. Wind Farms Have Been Known to Make Benign Echoes Appear as Small Storms. This Example Is from the Buffalo Radar................................................................................................................... 3- 56 Figure 3-27. Visible Satellite Image—U.S. Example ............................................................................................. 3- 58 Figure 3-28. Visible Satellite Data Legend ............................................................................................................. 3- 58 Figure 3-29. Infrared (Color) Satellite Image—U.S. Example ............................................................................... 3- 59
Figure 3-30. Unenhanced Infrared (Black and White) Satellite Image—U.S. Example3-60
Figure 3-31. Infrared (Color) Satellite Image Data Legend .................................................................................... 3- 60
Figure 3-32. Unenhanced Infrared (Black and White) Satellite Image Data Legend3-60
Figure 3-33. Water Vapor Satellite Image—U.S. Example .................................................................................... 3- 61 F igure 3-34. Water Vapor Satellite Image Data Legend ......................................................................................... 3- 62 Figure 3-35. U.S. Radiosonde Network .................................................................................................................. 3- 63 Figure 3-36. AAWU Surface Observations Example ............................................................................................. 3- 64 Figure 3-37. AAWU Surface Observation Plot Legend ......................................................................................... 3- 65
Figure 3-38. Surface Observations—Aviationweather.gov METAR Interactive Display Example3-69
Figure 3-39. Interactive Display Station Plot Example .......................................................................................... 3- 70 Figure 3-40. Station Plot Sky Symbols ................................................................................................................... 3- 72
Figure 3-41. Surface Observations—Aviationweather.gov METAR Static Display Example3-73
Figure 3-42. Static Display Station Plot Example .................................................................................................. 3- 73 Figure 3-43. Map of FAA’s Aviation Weather Camera Network in Alaska........................................................... 3- 75
Figure 3-44. Sectional Chart Depicting Shungnak (SHG), Alaska Camera Orientations3-75
Figure 3-45. “Clear Day” Image from Aviation Weather Camera Image at Shungnak (SHG), Alaska3-76
Figure 3-46. Aviation Weather Camera Image at Shungnak (SHG), Alaska .......................................................... 3- 76
Figure 4-1. NWS Surface Analysis Chart Example4-1
Figure 4-2. NWS Surface Analysis and Radar Composite Example4-2
Figure 4-3. NWS Surface Analysis Chart Symbols4-3
Figure 4-4. NWS Surface Analysis Chart Station Plot Model4-4
Figure 4-5. NWS Surface Analysis Chart Ship/Buoy Plot Model4-4
Figure 4-6. NWS Surface Analysis Chart for Aviation Interests Station Plot Model4-5
Figure 4-7. NWS Surface Analysis Chart Common Weather Symbols4-6
Figure 4-8. NWS Surface Analysis Chart Wind Plotting Model4-7
Figure 4-9. NWS Surface Analysis Chart Pressure Trends4-8
F
igure 4-10. NWS Surface Analysis Chart Sky Cover Symbols4-9
Figure 4-11. Unified Surface Analysis Chart Example .......................................................................................... 4- 11 Figure 4-12. Unified Surface Analysis Chart Example .......................................................................................... 4- 12
Figure 4-13. Unified Surface Analysis Chart Example With Fixed Area Coverage Over Alaska4-13
Figure 4-14. CONUS Display of CVA Ceiling Analysis........................................................................................ 4- 15 Figure 4-15. Regional Display of CVA Ceiling Analysis ....................................................................................... 4- 16 Figure 4-16. Regional Display of CVA Visibility Analysis ................................................................................... 4- 17 Figure 4-17. Regional Display of CVA Flight Category Analysis ......................................................................... 4- 18 Figure 4-18. Weather Depiction Chart—Example.................................................................................................. 4- 20
Figure 4-19. NWS NCEP Central Operations Model Analyses and Guidance Web Site4-21
11/14/16 Aviation Weather Services AC 00-45H x Figure 4-20. 500 MB Analysis Chart—Example .................................................................................................... 4- 22 Figure 4-21. 500 MB Height, Temperature, and Wind, 00-hour Forecast (i.e., Model’s Analyses from the NWS’s North American Model (NAM) Example) ............................................................................ 4- 22 Figure 4-22. Skew-T Diagram—Example .............................................................................................................. 4- 24 Figure 4-23. Skew-T Diagram—Multiple Freezing Level Example ...................................................................... 4- 25 Figure 4-24. Skew-T Diagram—Cloud Top Example ............................................................................................ 4- 25
Figure 5-1. AWC SIGMET Areas of Responsibility—Continental U.S5-2
Figure 5-2. AWC SIGMET Areas of Responsibility—Atlantic Basin5-2
Figure 5-3. SIGMET Areas of Responsibility—Pacific Basin5-3
Figure 5-4. SIGMET for the Continental U.S.—Example5-5
Figure 5-5. AWC Convective SIGMET Areas of Responsibility5-8
Figure 5-6. Convective SIGMET Decoding—Example5-9
Figure 5-7. SIGMET Outside the Continental U.S. Decoding Example ................................................................ 5- 12 Figure 5-8. AWC AIRMET Areas of Responsibility—Continental U.S. ............................................................... 5- 17
Figure 5-9. AAWU Flight Advisory and Area Forecast (FA) Zones—Alaska5-17
Figure 5-10. WFO Honolulu AIRMET Areas of Responsibility—Hawaii ............................................................. 5- 18 Figure 5-11. AIRMET Bulletin Decoding—Example ............................................................................................ 5- 21 Figure 5-12. G- AIRMET—Ceiling and Visibility (IFR) Snapshot Example ......................................................... 5- 25 Figure 5-13. G- AIRMET—Mountain Obscuration Snapshot Example .................................................................. 5- 25 Figure 5-14. G- AIRMET—Icing Snapshot Example ............................................................................................. 5- 26 F igure 5-15. G- AIRMET—Freezing Level Snapshot Example .............................................................................. 5- 27 Figure 5-16. G- AIRMET—Turbulence-High Snapshot Example .......................................................................... 5- 28 Figure 5-17. G- AIRMET—Turbulence-Low Snapshot Example ........................................................................... 5- 28
Figure 5-18. G- AIRMET—Low-Level Wind Shear (LLWS) Snapshot Example5-29
Figure 5-19. G- AIRMET—Strong Surface Winds Snapshot Example .................................................................. 5- 30
Figure 5-20. Center Weather Service Unit (CWSU) Areas of Responsibility5-31
Figure 5-21. Center Weather Advisory (CWA) Decoding Example ...................................................................... 5- 32 Figure 5-22. Day 1 Categorical Convective Outlook Graphic Example ................................................................. 5- 36
Figure 5-23. Categorical Outlook Legend for Days 1-3 Convective Outlook Graphic Example5-36
Figure 5-24. Aviation Watch (polygon) Compared to Public Watch (shaded) Example5-39
Figure 5-25. CDM Collaborative Convective Forecast Planning (CCFP) Guidance—Example5-47
Figure 5-26. CDM Collaborative Convective Forecast Planning (CCFP) Guidance—Example5-48
Figure 5-27. CCFP Product Legend ........................................................................................................................ 5- 49 Figure 5-28. ECFP Example ................................................................................................................................... 5- 50 Figure 5-29. NCWF Example ................................................................................................................................. 5- 52 Figure 5-30. NCWF Hazard Scale .......................................................................................................................... 5- 53 Figure 5-31. NCWF One-Hour Extrapolated Forecast Polygon, Forecast Movement Velocity and Echo Tops—Example.................................................................................................................................. 5- 54 Figure 5-32. NCWF Past Performance Polygons—Example ................................................................................. 5- 55 Figure 5-33. Volcanic Ash Advisory Centers (VAACs)......................................................................................... 5- 59 Figure 5-34. Volcanic Ash Advisory in Graphical Format ..................................................................................... 5- 61 F
igure 5-35. AWC Area Forecast (FA) Region and WMO Header—Gulf of Mexico5-62
Figure 5-36. AWC Area Forecast (FA) Region and WMO Header—Caribbean5-63
Figure 5-37. AAWU Flight Advisory and Area Forecast (FA) Zones—Alaska5-63
Figure 5-38. Alaskan Graphical Area Forecast (FA)—Flying Weather Example5-71
Figure 5-39. Alaskan Graphical Area Forecast (FA)—Surface Chart Example5-72
Figure 5-40. Alaskan Graphical Area Forecast (FA)—Icing Forecast Example5-73
Figure 5-41. Alaskan Graphical Area Forecast (FA)—Turbulence Forecast Example5-74
Figure 5-42. Alaskan Graphical Area Forecast (FA)—Convective Outlook .......................................................... 5- 75 Figure 5-43. FB Wind and Temperature Aloft Interactive Display Example ......................................................... 5- 97 Figure 5-44. Aviationweather.gov Freezing Level Graphic—Example ............................................................... 5- 102
Figure 5-45. NWS NCEP Central Operations Model Analyses and Guidance Web Site5-103
Figure 5-46. 300 MB Constant Pressure Forecast—Example .............................................................................. 5- 104 Figure 5-47. NDFD Surface Prog Forecast—Example ......................................................................................... 5- 106 Figure 5-48. Surface Prog Forecast Symbols ........................................................................................................ 5- 107 Figure 5-49. 12-Hour Low-Level SIGWX Chart—Example ................................................................................ 5- 109
11/14/16 Aviation Weather Services AC 00-45H xi Figure 5-50. Low-Level SIGWX Chart Symbols ................................................................................................. 5- 110 Figure 5-51. Low-Level SIGWX Chart Flying Categories—Example ................................................................. 5- 110 Figure 5-52. Low-Level SIGWX Chart Turbulence Forecast—Example............................................................. 5- 111 Figure 5-53. Low-Level SIGWX Chart Freezing Level Forecast—Example ....................................................... 5- 112 Figure 5-54. Low-Level SIGWX Chart Multiple Freezing Levels—Example ..................................................... 5- 113 Figure 5-55. Mid-Level SIGWX Chart—Example ............................................................................................... 5- 114 Figure 5-56. High-Level SIGWX Chart—Example ............................................................................................. 5- 117 Figure 5-57. High-Level SIGWX Chart Turbulence—Examples ......................................................................... 5- 119 Figure 5-58. High-Level SIGWX Chart Jet Stream—Example ............................................................................ 5- 120 Figure 5-59. High-Level SIGWX Chart Tropopause Height—Examples ............................................................ 5- 120 Figure 5-60. High-Level SIGWX Chart Tropical Cyclone—Examples ............................................................... 5- 121 Figure 5-61. High-Level SIGWX Chart Volcanic Eruption Site—Example ........................................................ 5- 121
Figure 5-62. High-Level SIGWX Chart Widespread Sandstorm and Duststorm—Example5-121
Figure 5-63. Alaska Significant Weather Chart—Example .................................................................................. 5- 123
Figure 5-64. WAFS Wind and Temperature 6-hour Forecast at FL 390—Example5-126
Figure 5-65. WAFS CAT Forecast—Example ..................................................................................................... 5- 129 Figure 5-66. WAFS Turbulence Forecast—Example ........................................................................................... 5- 130 Figure 5-67. WAFS Icing Forecast—Example ..................................................................................................... 5- 131 Figure 5-68. WAFS CB Cloud Forecast—Example ............................................................................................. 5- 132 F igure 5-69. CIP/FIP Icing Probability (3,000 Feet MSL)—Example ................................................................. 5- 135 Figure 5-70. CIP/FIP Icing Probability—Max Example ...................................................................................... 5- 136 Figure 5-71. CIP/FIP Icing Severity (3,000 Feet MSL)—Example...................................................................... 5- 137 Figure 5-72. CIP/FIP Icing Severity—Max Example ........................................................................................... 5- 138
Figure 5-73. CIP/FIP Icing Severity Plus Supercooled Large Drops (SLD)—Example5-140
Figure 5-74. CIP/FIP Icing Severity Plus Supercooled Large Droplets (SLD)—Max Example5-141
Figure 5-75. GTG—Max Intensity Example CAT+MWT All Levels .................................................................. 5- 144 Figure 5-76. CAT+MWT Low Levels Example (GA Users) ............................................................................... 5- 145 Figure 5-77. Explicit MWT Forecasts Example ................................................................................................... 5- 146
Figure 5-78. Map of NWS Weather Forecast Office’s Area of Responsibility5-148
Figure 5-79. NDFD Sky Cover Graphic Product—Example ................................................................................ 5- 151 Figure 5-80. NDFD Sky Cover Graphic Product—Example ................................................................................ 5- 152 Figure 5-81. NDFD Weather Graphic Product—Example ................................................................................... 5- 153 Figure 5-82. NDFD Weather Graphic Product—Example ................................................................................... 5- 154 Figure 5-83. Legend for NDFD Weather Graphic ................................................................................................ 5- 155 Figure 5-84. NDFD Weather Graphic Product—Example ................................................................................... 5- 156 Figure 5-85. NDFD Weather Graphic Product—Example ................................................................................... 5- 157 Figure 5-86. NDFD Weather Graphic Product—Example ................................................................................... 5- 157 Figure 5-87. NDFD Surface Wind Speed and Direction—Example .................................................................... 5- 158 Figure 5-88. NDFD Wind Speed and Direction Graphic Product Plot Model ...................................................... 5- 159 Figure 5-89. NDFD Surface Wind Gust Graphic—Example ............................................................................... 5- 159 F igure 5-90. Cloud Top Heights Product—Example ............................................................................................ 5- 161
Figure 6-1. HEMS Ceiling with Flight Category Overlay—Example6-3
Figure 6-2. HEMS Visibility with Flight Category Overlay—Example6-3
Figure 6-3. HEMS Flight Category with Flight Category Overlay—Example6-4
Figure 6-4. HEMS Radar Display—Example6-5
Figure 6-5. HEMS Satellite Imagery—Example6-6
Figure 6-6. HEMS Icing Severity—Example6-7
Figure 6-7. HEMS Icing Probability—Example6-7
Figure 6-8. HEMS Temperature—Example6-8
Figure 6-9. HEMS Relative Humidity—Example6-9
Figure 6-10. HEMS Wind Speed with Windbarb—Example6-9
Figure 6-11. HEMS Data Overlays with Text METAR—Example ....................................................................... 6- 12 Figure 6-12. Configure Menu—Example ............................................................................................................... 6- 13
11/14/16 Aviation Weather Services AC 00-45H xii TABLES Number Page Table 1-1. FIS-B Over UAT Product Update and Transmission Intervals.............................................................. 1- 12 Table 1-2. Product Parameters for Low/Medium/High Altitude Tier Radios ......................................................... 1- 13
Table 3-1. SPECI Criteria3-2
Table 3-2. METAR/SPECI Notations for Reporting Present Weather1 .................................................................. 3- 10 Table 3-3. METAR/SPECI Contractions for Sky Cover ......................................................................................... 3- 15
Table 3-4. METAR/SPECI Increments of Reportable Values of Sky Cover Height3-15
Table 3-5. METAR/SPECI Order of Remarks ........................................................................................................ 3- 18 Table 3-6. METAR/SPECI Type and Frequency of Lightning ............................................................................... 3- 21 Table 3-7. WSR-88D Weather Radar Precipitation Intensity Terminology ............................................................ 3- 41 Table 3-8. AAWU Surface Observations Flying Categories and Criteria ............................................................... 3- 65 Table 3-9. AAWU Surface Observation Precipitation Symbols ............................................................................. 3- 67
Table 3-10. AAWU Surface Observation Obstruction to Visibility Symbols3-68
Table 3-11. AAWU Surface Observation Precipitation Intensity Symbols ............................................................ 3- 68 Table 3-12. Rounding of Actual METAR Visibility Values for Depiction on Aviationweather.gov/AWC METAR Display .................................................................................................................................. 3- 71 Table 3-13. Station Plot Weather Categories .......................................................................................................... 3- 72
Table 5-1. Decoding a SIGMET (Non-Convective) for the Continental U.S5-6
Table 5-2. Decoding a Convective SIGMET5-9
Table 5-4. AAWU Flight Advisory and Area Forecast (FA) Zones—Alaska5-18
Table 5-5. AIRMET Issuance Schedule .................................................................................................................. 5- 20 Table 5-6. Decoding an AIRMET Bulletin ............................................................................................................. 5- 22 Table 5-7. G- AIRMET Issuance Schedule.............................................................................................................. 5- 24 Table 5-8. Decoding a Center Weather Advisory (CWA) ...................................................................................... 5- 33 Table 5-9. Convective Outlook Issuance Schedule ................................................................................................. 5- 35 Table 5-10. Decoding an Aviation Weather Watch Notification Message ............................................................. 5- 41 Table 5-11. AAWU Area Forecast (FA) Zones—Alaska ....................................................................................... 5- 64 Table 5-12. Area Forecast (FA) Issuance Schedule ................................................................................................ 5- 65 Table 5-13. Generic Format of NWS TAFs ............................................................................................................ 5- 76 Table 5-14. TAF Fog Terms ................................................................................................................................... 5- 83 Table 5-15. TAF Use of Vicinity (VC) ................................................................................................................... 5- 84 Table 5-16. TAF Sky Cover .................................................................................................................................... 5- 84 Table 5-17. TAF Issuance Schedule ........................................................................................................................ 5- 92 Table 5-18. Wind and Temperature Aloft Forecast Decoding Examples .............................................................. 5- 100 Table 5-19. Wind and Temperature Aloft Forecast (FB) Periods ......................................................................... 5- 100 Table 5-20. Select Constant Pressure Levels From the GFS Model ..................................................................... 5- 105 Table 5-21. Short-Range Surface Prog Forecast Schedule .................................................................................... 5- 108 Table 5-22. Low-Level SIGWX Chart Issuance Schedule .................................................................................... 5- 113 Table 5-23. Icing and Turbulence Intensity Symbols ............................................................................................ 5- 115 Table 5-24. Mid-Level SIGWX Chart Issuance Schedule .................................................................................... 5- 116 Table 5-25. High-Level SIGWX FORECAST Issuance Schedule ....................................................................... 5- 122 Table 5-26. WAFS Clear Air Turbulence Forecasts ............................................................................................. 5- 128 Table 5-27. WAFS In-Cloud Turbulence Forecasts .............................................................................................. 5- 130 Table 5-28. WAFS Global Icing Forecasts ........................................................................................................... 5- 131
Table 6-1. Flight Categories6-2