Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
4.2.2 Imagery Types4-16
4.2.2.1 Visible Imagery .............................................................................................................................................. 4- 16 Figure 4-17. Visible Satellite Image – U.S. Example ........................................................................... 4- 17
Figure 4-18. Visible Satellite Image – Regional-Scale Example4-18
Visible Image Data Legend4-18
Figure 4-19. Visible Satellite Data Legend .......................................................................................... 4- 18
4.2.2.2 Infrared (IR) Imagery ..................................................................................................................................... 4- 18
Figure 4-20. Infrared (Color) Satellite Image – U.S. Example4-19
Figure 4-21. Infrared (Color) Satellite Image – Regional-Scale Example4-20
Figure 4-22. Unenhanced Infrared (Black and White) Satellite Image – U.S. Example4-20
Figure 4-23. Unenhanced Infrared (Black and White) Satellite Image – Regional-Scale Example . 4-21
Infrared Image Data Legends4-21
Figure 4-24. Infrared (Color) Satellite Image Data Legend ............................................................... 4- 21
Figure 4-25. Unenhanced Infrared (Black and White) Satellite Image Data Legend4-21
4.2.2.3 Water Vapor Imagery ..................................................................................................................................... 4- 21 Figure 4-26. Water Vapor Satellite Image – U.S. Example ................................................................ 4- 22
Figure 4-27. Water Vapor Satellite Image – Regional-Scale Example4-23
Water Vapor Image Data Legend4-23
Figure 4-28. Water Vapor Satellite Image Data Legend .................................................................... 4- 23
5 GRAPHICAL OBSERVATIONS AND DERIVED PRODUCTS5-1
5.1 SURFACE ANALYSIS CHARTS5-1
Figure 5-1. HPC Surface Analysis Chart Example5-1
5.1.1 Issuance5-1
5.1.2 HPC Surface Analysis Charts5-2
5.1.2.1 Issuance5-2
Table 5-1. HPC Surface Analysis Charts Issuance Schedule5-2
5.1.2.2 Analysis Symbols5-2
Figure 5-2. HPC Surface Analysis Chart Symbols5-3
5.1.2.3 Station Plot Models5-3
Figure 5-3. HPC Surface Analysis Chart Station Plot Model5-3
Figure 5-4. HPC Surface Analysis Chart Ship/Buoy Plot Model5-4
Figure 5-5. HPC Surface Analysis Chart for Aviation Interests Station Plot Model5-4
Station Identifier5-4
Temperature5-4
Dew Point5-5
Weather5-5
Figure 5-6. HPC Surface Analysis Chart Common Weather Symbols5-5
Wind5-5
Figure 5-7. HPC Surface Analysis Chart Wind Plotting Model5-6
Ceiling5-6
Visibility5-6
Pressure5-6
Pressure Trend5-6
Figure 5-8. HPC Surface Analysis Chart Pressure Trends5-7
Sky Cover5-7
Figure 5-9. HPC Surface Analysis Chart Sky Cover Symbols5-7
Water Temperature5-7
Swell Information5-8
Wave Information5-8
5.1.2.4 Analyses5-8
Isobars5-8
Pressure Systems5-9
Fronts5-9
Figure 5-10. HPC Surface Analysis Chart – North America Example5-9
Figure 5-11. HPC Surface Analysis Chart – Contiguous U.S. Example5-10
Figure 5-12. HPC Surface Analysis Chart – Northeast U.S. Example5-10
Figure 5-13. HPC Surface Analysis Chart for Aviation Interests – Contiguous U.S. Example5-11
Figure 5-14. HPC Surface Analysis Chart for Aviation Interests – South central U.S. Example5-11
5.1.3 OPC and WFO Honolulu Surface Analysis Charts5-12
5.1.3.1 Issuance .......................................................................................................................................................... 5- 12
Table 5-2. OPC and WFO Honolulu Surface Analysis Charts Issuance Schedule5-12
Table of Contents vi
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
5.1.3.2 Analysis Symbols ........................................................................................................................................... 5- 12
Figure 5-15. OPC and WFO HNL Surface Analysis Chart Symbols5-12
Figure 5-16. WFO HNL Surface Analysis Chart – North Pacific Example5-13
5.1.3.3 Wave Information ........................................................................................................................................... 5- 13
5.1.3.4 Analyses ......................................................................................................................................................... 5- 13
Isobars5-14
Pressure Systems5-14
Fronts5-14
5.1.4 TPC Surface Analysis Charts5-14
5.1.4.1 Issuance .......................................................................................................................................................... 5- 14
Table 5-3. TPC Surface Analysis Charts Issuance Schedule5-14
5.1.4.2 Analysis Symbols ........................................................................................................................................... 5- 14 Figure 5-17. TPC Surface Analysis Chart Symbols ............................................................................ 5- 15
Figure 5-18. TPC Tropical Surface Analysis Chart Example5-15
Wind5-15
Figure 5-19. TPC Surface Analysis Chart Wind Plotting Model5-16
5.1.4.3 Analyses ......................................................................................................................................................... 5- 16
Isobars5-16
Pressure Systems5-16
Fronts5-17
5.1.5 Unified Surface Analysis Chart5-17
5.1.5.1 Issuance .......................................................................................................................................................... 5- 17
Table 5-4. Unified Surface Analysis Chart Issuance Schedule5-17
Figure 5-20. Unified Surface Analysis Chart Example....................................................................... 5- 17
5.1.5.2 Analysis Symbols ........................................................................................................................................... 5- 17 Figure 5-21. Unified Surface Analysis Chart Symbols ....................................................................... 5- 18
5.1.5.3 Analyses ......................................................................................................................................................... 5- 18
Isobars5-18
Pressure Systems5-18
Fronts5-18
5.1.6 AAWU Surface Charts5-19
5.1.6.1 Issuance .......................................................................................................................................................... 5- 19 Table 5-5. AAWU Surface Analysis Issuance Schedule ..................................................................... 5- 19
5.1.6.2 Analysis Symbols ........................................................................................................................................... 5- 19 Figure 5-22. AAWU Surface Analysis Chart Symbols ....................................................................... 5- 19 Figure 5-23. AAWU Alaskan Surface Chart Example ....................................................................... 5- 20
5.1.6.3 Station Plot Models ........................................................................................................................................ 5- 20
Figure 5-24. AAWU Surface Analysis Chart Station Plot Model5-20
Figure 5-25. AAWU Surface Analysis Chart Ship/Buoy Plot Model5-21
Station Identifier5-21
Temperature5-21
Dew Point5-21
Wind5-21
Figure 5-26. AAWU Surface Analysis Chart Wind Plotting Model5-22
Ceiling5-22
Visibility5-22
Pressure5-22
Pressure Trend5-22
Figure 5-27 AAWU Surface Analysis Chart Pressure Trends5-23
Sky Cover5-23
Figure 5-28. AAWU Surface Analysis Chart Sky Cover Symbols5-23
Water Temperature5-23
Swell Information5-24
Wave Information5-24
5.1.6.4 Analyses ......................................................................................................................................................... 5- 24
Isobars5-24
Pressure Systems5-25
Fronts5-25
5.2 CONSTANT PRESSURE CHARTS5-26
Figure 5-29. Constant Pressure Chart Example ................................................................................. 5- 26
5.2.1 Issuance5-26
Table of Contents vii
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
5.2.2 Observational Data5-26
Figure 5-30. U.S. Radiosonde Network ............................................................................................... 5- 27 Table 5-6. Features of Constant Pressure Charts ............................................................................... 5- 28 Table 5-7. Constant Pressure Chart Plotting Models ......................................................................... 5- 28 Table 5-8. Radiosonde Plotting Model Examples ............................................................................... 5- 29
5.2.3 Analyses5-29
5.2.3.1 Height ............................................................................................................................................................. 5- 29
5.2.3.2 Temperature ................................................................................................................................................... 5- 29
5.2.3.3 Wind Speed .................................................................................................................................................... 5- 30
5.2.3.4 Use ................................................................................................................................................................. 5- 30
Table 5-9. Reconnaissance Aircraft (RECCO) Plotting Model Examples5-30
Table 5-10. Aircraft Report (AIREP) Plotting Model Examples5-31
Table 5-11. Satellite Wind Estimate Plotting Model Examples5-31
Figure 5-31. 850MB Analysis Chart Example .................................................................................... 5- 32 Figure 5-32. 700MB Analysis Chart Example .................................................................................... 5- 32 Figure 5-33. 500MB Analysis Chart Example .................................................................................... 5- 33 Figure 5-34. 300MB Analysis Chart Example .................................................................................... 5- 33 Figure 5-35. 200MB Analysis Chart Example .................................................................................... 5- 34
5.3 FREEZING-LEVEL GRAPHICS5-35
5.3.1 Issuance5-35
5.3.2 Observational Data5-35
5.3.3 Format5-36
Figure 5-36. RUC 00-Hour Freezing Level Graphic Example5-37
5.3.4 Use5-38
Figure 5-37. A DDS Freezing Level Graphic Example ........................................................................ 5- 38
5.4 WEATHER DEPICTION CHART5-39
Figure 5-39. Weather Depiction Chart Example ................................................................................ 5- 39
5.4.1 Issuance5-39
Table 5-13. Weather Depiction Charts Issuance Schedule ................................................................. 5- 39
5.4.2 Station Plot Model5-39
Figure 5-40. Weather Depiction Chart Station Plot Model ................................................................ 5- 40
5.4.2.1 Visibility ......................................................................................................................................................... 5- 40
5.4.2.2 Present Weather .............................................................................................................................................. 5- 40
5.4.2.3 Sky Cover ....................................................................................................................................................... 5- 40
5.4.2.4 Ceiling ............................................................................................................................................................ 5- 40
5.4.3 Weather Flying Category Analysis5-41
5.4.4 Use5-41
5.5 ALASKA WEATHER DEPICTION CHARTS5-42
Figure 5-41. AAWU Alaska Weather Depiction Chart Example5-42
Table 5-14. AAWU Alaska Weather Depiction Charts Coverage5-43
5.5.1 Issuance5-43
5.5.2 Legends5-43
5.5.2.1 Flying Category .............................................................................................................................................. 5- 43
Table 5-15. AAWU Alaska Weather Flying Categories and Criteria5-43
5.5.2.2 Station Plot ..................................................................................................................................................... 5- 43
Figure 5-42. AAWU Alaska Weather Depiction Chart Station Plot Legend5-43
5.5.2.3 Sky Cover ....................................................................................................................................................... 5- 44
5.5.2.4 Station Identifier (STNID) .............................................................................................................................. 5- 44
5.5.2.5 Wind ............................................................................................................................................................... 5- 44
Figure 5-43. A AWU Alaska Weather Depiction Chart Wind Symbols5-44
5.5.2.6 Temperature (TMP deg F) .............................................................................................................................. 5- 44
5.5.2.7 Visibility (VIS) ............................................................................................................................................... 5- 44
5.5.2.8 Dew Point Temperature (DEWPT deg F) ....................................................................................................... 5- 45
5.5.2.9 Ceiling (CIG) .................................................................................................................................................. 5- 45
5.5.2.10 Present Weather (WX) .................................................................................................................................... 5- 45
Table 5-16. Alaska Weather Depiction Charts Precipitation Symbols5-45
Table 5-17. Alaska Weather Depiction Charts Obstruction to Visibility Symbols5-45
Table 5-18. Alaska Weather Depiction Charts Precipitation Intensity Symbols5-46
5.5.3 Use5-47
Table of Contents viii
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
Figure 5-44. AAWU Alaska Weather Depiction Chart – South Central Alaska Example5-47
5.6 RADAR SUMMARY CHART5-48
Figure 5-45. Radar Summary Chart Example5-48
5.6.1 Issuance5-48
5.6.2 Format5-48
5.6.2.1 Precipitation Type .......................................................................................................................................... 5- 48
Table 5-19. Radar Summary Chart Precipitation Type Symbols5-49
5.6.2.2 Precipitation Intensity5-49
Figure 5-46. WSR-88D Weather Radar Network5-49
Figure 5-47. Radar Summary Chart Precipitation Intensity5-50
5.6.2.3 Echo Coverage ............................................................................................................................................... 5- 50
5.6.2.4 Line Echoes .................................................................................................................................................... 5- 50
Table 5-20. Radar Summary Chart Echo Configuration Symbols5-50
5.6.2.5 Cell Movement ............................................................................................................................................... 5- 50
Table 5-21. Radar Summary Chart Cell Movement Examples5-51
5.6.2.6 Maximum Top5-51
Figure 5-48. Radar Summary Chart Maximum Top Example5-51
5.6.2.7 Weather Watch Areas5-52
Table 5-22. Radar Summary Chart Weather Watch Area Examples5-52
5.6.2.8 Operational Contractions5-52
Table 5-23. Radar Summary Chart Operational Contractions5-52
5.6.3 Use5-52
Figure 5-49. Radar Summary Chart Example5-53
5.7 ALASKA INITIAL GEOPOTENTIAL HEIGHTS AND WINDS CHARTS5-54
Figure 5-50. Alaskan Initial Geopotential Heights and Winds Chart Example5-54
Table 5-24. Pressure Altitudes of Alaska Initial Geopotential Heights and Winds Charts5-54
5.7.1 Issuance5-54
5.7.2 Analysis5-55
5.7.2.1 Height Contours ............................................................................................................................................. 5- 55
5.7.2.2 Winds5-55
Figure 5-51. Alaskan Initial Geopotential Heights and Winds Chart Wind Plotting Model5-55
5.7.3 Use5-55
Figure 5-52. Alaskan Initial Geopotential Heights and Winds Chart – 200MB Winds and Contours Chart Example ............................................................................................... 5- 56 Figure 5-53. Alaskan Initial Geopotential Heights and Winds Chart – 300MB Winds and Contours Chart Example ............................................................................................... 5- 56 Figure 5-54. Alaskan Initial Geopotential Heights and Winds Chart – 500MB Winds and Contours Chart Example ............................................................................................... 5- 57 Figure 5-55. Alaskan Initial Geopotential Heights and Winds Chart – 700MB Winds and Contours Chart Example ............................................................................................... 5- 57 Figure 5-56. Alaskan Initial Geopotential Heights and Winds Chart – 850MB Winds and Contours Chart Example ............................................................................................... 5- 58
6 PRODUCTS FOR AVIATION HAZARDS6-1
6.1 SIGNIFICANT METEOROLOGICAL INFORMATION (SIGMET)6-1
6.1.1 SIGMET Issuance6-1
Figure 6-1. AWC SIGMET Areas of Responsibility – Conterminous U.S6-2
Figure 6-2. AWC SIGMET Areas of Responsibility – Atlantic Basin6-2
Figure 6-3. SIGMET Areas of Responsibility – Pacific Basin6-3
6.1.1.1 SIGMET Identification6-3
6.1.2 SIGMET Standardization6-4
6.1.3 SIGMET (Non-Convective) – Conterminous U.S6-4
6.1.3.1 SIGMET (Non-Convective) Issuance Criteria – Contiguous U.S6-4
6.1.3.2 SIGMET (Non-Convective) Issuance Time and Valid Period – Conterminous U.S6-5
6.1.3.3 SIGMET (Non-Convective) Format – Conterminous U.S6-5
Figure 6-4. SIGMET for the Conterminous U.S. Decoding Example6-6
Table 6-1. Decoding a SIGMET (Non-Convective) for the Conterminous U.S6-6
6.1.3.4 SIGMET (Non-Convective) Cancellations – Conterminous U.S6-7
6.1.3.5 SIGMET (Non-Convective) Amendments – Conterminous U.S6-7
6.1.3.6 SIGMET (Non-Convective) Corrections – Conterminous U.S6-7
Table of Contents ix
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
6.1.3.7 SIGMET (Non-Convective) Example – Conterminous U.S6-7
6.1.4 Convective SIGMET6-7
6.1.4.1 Convective SIGMET – Routine Issuance Criteria6-7
6.1.4.2 Convective SIGMET – Special Issuance Criteria6-8
6.1.4.3 Convective SIGMET Issuance Time and Valid Period6-8
Figure 6-5. AWC Convective SIGMET Areas of Responsibility6-8
6.1.4.4 Convective SIGMET Format6-8
Figure 6-6. Convective SIGMET Decoding Example ......................................................................... 6- 10 Table 6-2. Decoding a Convective SIGMET ....................................................................................... 6- 10
6.1.4.5 Convective SIGMET Outlook ........................................................................................................................ 6- 11
6.1.4.6 Convective SIGMET Cancellations ................................................................................................................ 6- 11
6.1.4.7 Convective SIGMET Amendments ................................................................................................................ 6- 11
6.1.4.8 Convective SIGMET Corrections ................................................................................................................... 6- 11
6.1.4.9 Convective SIGMET Bulletin Examples ........................................................................................................ 6- 11
Convective SIGMET Bulletin – Tropical Cyclone Example6-12
6.1.5 SIGMET – Outside the Conterminous U.S. (O-CONUS)6-14
6.1.5.1 SIGMET Issuance Criteria – Outside the Conterminous U.S. (O-CONUS)6-14
6.1.5.2 SIGMET Issuance Time and Valid Period – Outside the Conterminous U.S. (O-CONUS)6-14
6.1.5.3 SIGMET Format – Outside the Conterminous U.S. (O-CONUS) ................................................................... 6- 14
Figure 6-7. SIGMET Outside the Conterminous U.S. Decoding Example6-16
Table 6-3. Decoding a SIGMET Outside of the Conterminous U.S. (O-CONUS)6-16
6.1.5.4 SIGMETs for Volcanic Ash ........................................................................................................................... 6- 17
6.1.5.5 SIGMETs for Tropical Cyclone ...................................................................................................................... 6- 17
6.1.5.6 SIGMET Cancellation – Outside the Conterminous U.S. (O-CONUS)6-17
6.1.5.7 SIGMET Amendments – Outside the Conterminous U.S. (O-CONUS)6-17
6.1.5.8 SIGMET Corrections – Outside the Conterminous U.S. (O-CONUS)6-17
6.1.5.9 SIGMET Example – Outside the Conterminous U.S. (O-CONUS) ................................................................ 6- 18
SIGMET for Volcanic Ash Example6-18
SIGMET for Tropical Cyclone Example6-18
6.2 AIRMEN’S METEOROLOGICAL INFORMATION (AIRMET)6-20
6.2.1 AIRMET Issuance6-20
Figure 6-8. AWC AIRMET Areas of Responsibility – Conterminous U.S6-21
Figure 6-9. AAWU Flight Advisory and Area Forecast Zones – Alaska6-22
Table 6-4. AAWU Flight Advisory and Area Forecast Zones – Alaska6-22
Figure 6-10. WFO Honolulu AIRMET Areas of Responsibility – Hawaii6-23
6.2.2 AIRMET Issuance Criteria6-23
6.2.3 AIRMET Standardization6-24
6.2.4 AIRMET Bulletins, Issuance Times, and Valid Period6-24
Table 6-5. AIRMET Issuance Schedule............................................................................................... 6- 24
6.2.5 AIRMET Format6-25
Figure 6-11. AIRMET Bulletin Decoding Example ............................................................................ 6- 26 Table 6-6. Decoding an AIRMET Bulletin .......................................................................................... 6- 26
6.2.5.1 AIRMET Updates and Amendments .............................................................................................................. 6- 27
6.2.5.2 AIRMET Corrections ..................................................................................................................................... 6- 27
6.2.6 AIRMET Examples6-27
6.2.6.1 CONUS AIRMET Example ........................................................................................................................... 6- 27
6.2.6.2 Hawaii AIRMET Example ............................................................................................................................. 6- 29
6.2.6.3 Alaska AIRMET Example .............................................................................................................................. 6- 29
6.3 GRAPHICAL AIRMAN’S METEOROLOGICAL ADVISORY (G-AIRMET)6-31
6.3.1 G-AIRMET Issuance6-31
Table 6-7. G-AIRMET Issuance Schedule .......................................................................................... 6- 31
6.3.2 G-AIRMET Content6-31
Figure 6-12. G-AIRMET – Ceiling and Visibility (IFR) Snapshot Example6-32
Figure 6-13. G- AIRMET – Mountain Obscuration Snapshot Example6-33
Figure 6-14. G-AIRMET – Icing Snapshot Example ......................................................................... 6- 34
Figure 6-15. G-AIRMET – Freezing Level Snapshot Example6-35
Figure 6-16. G-AIRMET – Turbulence-High Snapshot Example6-36
Figure 6-17. G-AIRMET – Turbulence-Low Snapshot Example6-37
Figure 6-18. G-AIRMET – Low-Level Wind Shear (LLWS) Snapshot Example6-38
Figure 6-19. G-AIRMET – Strong Surface Winds Snapshot Example6-39
Table of Contents x
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
6.4 CENTER WEATHER ADVISORY (CWA)6-40
6.4.1 CWA Issuance6-40
Figure 6-20. Center Weather Service Unit (CWSU) Areas of Responsibility, Contiguous U.S6-40
Figure 6-21. CWSU Anchorage, AK (PAZA) Area of Responsibility6-41
6.4.2 CWA Criteria6-41
6.4.3 CWA Format6-42
Figure 6-22. Center Weather Advisory (CWA) Decoding Example6-42
Table 6-8. Decoding a Center Weather Advisory (CWA) .................................................................. 6- 42
6.4.4 Examples6-43
6.5 ADDITIONAL PRODUCTS FOR CONVECTION6-45
6.5.1 Convective Outlooks (AC)6-45
6.5.1.1 Issuance .......................................................................................................................................................... 6- 45 Table 6-9. Convective Outlook Issuance Schedule.............................................................................. 6- 45
Figure 6-23. Day 1 Categorical Convective Outlook Graphic Example6-46
6.5.1.2 Format of the Categorical Convective Outlook Narrative ............................................................................... 6- 46
6.5.2 Watch Notification Messages6-47
6.5.2.1 Aviation Watch Notification Message ............................................................................................................ 6- 47
6.5.2.2 Format of an Aviation Watch Notification Message ....................................................................................... 6- 47
Figure 6-24. Aviation Watch Notification Message Decoding Example6-48
Table 6-10. Decoding a Severe Weather Watch Bulletin .................................................................... 6- 48
6.5.2.3 Issuance .......................................................................................................................................................... 6- 49
6.5.3 Public Severe Thunderstorm Watch Notification Message6-49
6.5.3.1 Format of Public Severe Thunderstorm Watch Notification Message6-49
6.5.3.2 Example of a Public Severe Thunderstorm Watch Notification Message6-50
6.5.4 Public Tornado Watch Notification Message6-51
6.5.4.1 F ormat of a Public Tornado Watch Notification Message .............................................................................. 6- 52
6.5.4.2 Example of a Public Tornado Watch Notification Message ............................................................................ 6- 53
6.6 PRODUCTS FOR TROPICAL CYCLONES6-55
6.6.1 Aviation Tropical Cyclone Advisory (TCA)6-55
6.6.1.1 Issuance .......................................................................................................................................................... 6- 55
6.6.1.2 Content ........................................................................................................................................................... 6- 55
6.6.1.3 Format6-55
6.6.1.4 Aviation Tropical Cyclone Advisory (TCA) Example6-56
6.6.1.5 Tropical Cyclone Public Advisory (TCP)6-56
6.6.1.6 TCP Responsibility6-56
6.6.1.7 TCP Issuance6-57
Table 6-11. Tropical Cyclone Public Advisory Issuance Schedule6-58
TCP Intermediate Issuances6-58
Table 6-12. Intermediate Tropical Cyclone Public Advisory Issuance Schedule6-59
6.6.1.8 TCP Content6-59
6.6.1.9 TCP Format .................................................................................................................................................... 6- 60
6.6.1.10 Tropical Storm Public Advisory (TCP) Example ............................................................................................ 6- 60
6.6.1.11 Hurricane/Typhoon Public Advisory Example ............................................................................................... 6- 61
6.6.1.12 Intermediate Public Advisory Example6-63
6.6.1.13 Special Public Advisory Example6-65
6.6.1.14 Public Advisory Correction Example6-66
6.7 VOLCANIC ASH ADVISORY PRODUCTS6-67
6.7.1 Volcanic Ash Advisory Center (VAAC)6-67
Figure 6-25. Volcanic Ash Advisory Centers (VAACs) Area of Responsibility6-67
6.7.2 Volcanic Ash Advisory Statement (VAAS)6-68
6.7.2.1 Issuance .......................................................................................................................................................... 6- 68
6.7.2.2 Format ............................................................................................................................................................ 6- 68
6.7.2.3 VAAS Issued by the Washington VAAC Example ........................................................................................ 6- 68
6.7.3 Volcanic Ash Advisory (VAA)6-69
6.7.3.1 VAA Issuance ................................................................................................................................................ 6- 69
6.7.3.2 VAA Format ................................................................................................................................................... 6- 69
6.7.3.3 Volcanic Ash Advisory (VAA) Example ........................................................................................................ 6- 70 Table of Contents xi
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
7 FORECAST TEXT PRODUCTS7-1
7.1 AREA FORECASTS (FA)7-1
7.1.1 Area Forecast Issuance7-1
Figure 7-1. AWC Area Forecast Regions – Contiguous U.S7-2
Figure 7-2. AWC Area Forecast Region and WMO Header – Gulf of Mexico7-2
Figure 7-3. AWC Area Forecast Region and WMO Header – Caribbean7-3
Figure 7-4. WFO Honolulu Area Forecast Region and WMO header – Hawaii7-3
Figure 7-5. AAWU Flight Advisory and Area Forecast Zones – Alaska7-4
Table 7-1. AAWU Area Forecast Zones – Alaska7-4
7.1.2 Area Forecast Standardization7-4
7.1.3 Area Forecast Issuance Schedule7-5
Table 7-2. Area Forecast (FA) Issuance Schedule7-5
7.1.4 Area Forecast Amendments7-5
7.1.5 Area Forecast Corrections7-6
7.1.6 Area Forecast Format – Conterminous U.S. (CONUS)7-6
Figure 7-6. Area Forecast – CONUS Communication and Product Header Example7-7
Table 7-3. Decoding a CONUS Area Forecast Communication and Product Header7-8
Figure 7-7. Area Forecast – Clouds and Weather Element Example7-8
7.1.6.1 Area Forecast – Conterminous U.S. (CONUS) Examples7-9
Area Forecast – BOS Example7-9
Area Forecast – SFO (FA) Example ....................................................................................................... 7- 10
7.1.7 Area Forecast Format – Gulf of Mexico (FAGX)7-12
7.1.7.1 Area Forecast – Gulf of Mexico (FAGX) Example7-13
7.1.8 Area Forecast Format – Caribbean (FACA)7-14
7.1.8.1 Area Forecast – Caribbean (FACA) Example7-14
7.1.9 Area Forecast Format – Hawaii7-15
7.1.9.1 Area Forecast – Hawaii Example7-15
7.1.10 Area Forecast Format – Alaska7-16
7.1.10.1 Area Forecast – Alaska Example7-17
7.2 TERMINAL AERODROME FORECAST (TAF)7-19
7.2.1 Responsibility7-19
7.2.2 Generic Format of the Forecast Text of a NWS-Prepared TAF7-19
Table 7-4. Generic Format of NWS TAFs ........................................................................................... 7- 19
7.2.2.1 Type of Report (TAF or TAF AMD or TAF COR) ........................................................................................ 7- 19
7.2.2.2 Location Identifier (CCCC) ............................................................................................................................ 7- 20
7.2.2.3 Date/Time of Forecast Origin Group (YYGGggZ) ......................................................................................... 7- 20
7.2.2.4 Valid Period (Y1Y1G1G1/Y2Y2G2G2) .......................................................................................................... 7- 20
7.2.2.5 Wind Group (dddffGfmfmKT) ........................................................................................................................ 7- 21
7.2.2.6 Visibility Group (VVVV) ............................................................................................................................... 7- 22
7.2.2.7 Significant Weather Group (w'w' or NSW) ..................................................................................................... 7- 22 Exception for Encoding Multiple Precipitation Types ............................................................................ 7- 23 Thunderstorm Descriptor ........................................................................................................................ 7- 24 Fog Forecast ........................................................................................................................................... 7- 24 Table 7-5. TAF Fog Terms ................................................................................................................... 7- 25
7.2.2.8 Vicinity (VC) .................................................................................................................................................. 7- 25 Table 7-6. TAF Use of Vicinity (VC) ................................................................................................... 7- 25
7.2.2.9 Cloud and Vertical Obscuration Groups (NsNsNshshshs or VVhshshs or SKC)7-25
Cloud Group (NsNsNshshshs) ................................................................................................................ 7- 26 Table 7-7. TAF Sky Cover.................................................................................................................... 7- 26
Vertical Obscuration Group (VVhshshs)7-26
Cloud Type (CB)7-26
7.2.2.10 Non-Convective Low-Level Wind Shear (LLWS) Group (WShwshwshws/dddffKT)7-27
7.2.2.11 Forecast Change Indicator Groups7-28
From (FM) Group (FMYYGGgg)7-28
TEMPO (YYGG/YeYeGeGe) Group7-29
PROB30 (YYGG/YeYeGeGe) Group7-30
7.2.2.12 TAF Examples7-30
7.2.3 Issuance7-33
Table 7-8. TAF Issuance Schedule ....................................................................................................... 7- 33
7.2.3.1 Minimum Observational Requirements for Routine TAF Issuance and Continuation7-33
Table of Contents xii
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
7.2.3.2 Sites with Scheduled Part-Time Observations7-33
Examples of Scheduled Part-Time Observations TAFs7-34
7.2.3.3 Automated Observing Sites Requiring Part-Time Augmentation7-34
7.2.3.4 Non-Augmented Automated Observing Sites7-35
7.3 INTERNATIONAL AVIATION ROUTE FORECASTS (ROFOR)7-37
7.3.1 ROFOR Criteria7-37
7.3.2 Issuance7-37
7.3.2.1 ROFOR Amendments7-37
7.3.2.2 ROFOR Corrections7-37
7.3.3 ROFOR Content7-37
7.3.4 ROFOR Examples7-38
7.3.4.1 Santa Barbara and San Francisco to Honolulu Route ROFOR Example
7.4 WIND AND TEMPERATURE ALOFT FORECAST (FB)7-39
7.4.1 Forecast Altitudes7-39
Table 7-9. Wind and Temperature Aloft Forecast Levels .................................................................. 7- 39
7.4.2 Format7-39
7.4.2.1 Coding Example7-39
Table 7-10. Wind and Temperature Aloft Forecast Decoding Examples7-41
7.4.2.2 Example for the Contiguous US and Alaska7-41
7.4.2.3 Example for Hawaii and the Western Pacific7-41
7.4.3 Issuance7-42
Figure 7-8. Wind and Temperature Aloft Forecast Network – Contiguous U.S7-42
Figure 7-9. Wind and Temperature Aloft Forecast Network – Alaska7-43
Figure 7-10. Wind and Temperature Aloft Forecast Network – Hawaii7-43
Figure 7-11. Wind and Temperature Aloft Forecast Network – Western Pacific7-44
Table 7-11. Wind and Temperature Aloft Forecast (FB) Periods7-44
7.4.4 Delayed Forecasts7-44
8 FORECAST CHARTS8-1
8.1 SHORT-RANGE SURFACE PROGNOSTIC (PROG) CHARTS8-1
Figure 8-1. Surface Prog Chart Example8-1
8.1.1 Content8-2
Figure 8-2. Surface Prog Chart Symbols8-2
8.1.1.1 Pressure Systems8-2
8.1.1.2 Fronts8-2
8.1.1.3 Squall Lines8-2
8.1.1.4 Precipitation8-2
Figure 8-3. Surface Prog Chart Precipitation Symbols8-3
Figure 8-4. Surface Prog Chart Precipitation Example8-3
Figure 8-5. Surface Prog Chart Precipitation Coverage8-4
8.1.2 Issuance8-4
Table 8-1. Short-Range Surface Prog Charts Schedule8-4
8.1.3 Use8-4
Figure 8-6. 12-Hour Surface Prog Chart Example8-5
Figure 8-7. 24-Hour Surface Prog Chart Example8-5
Figure 8-8. 36-Hour Surface Prog Chart Example8-6
Figure 8-9. 48-Hour Surface Prog Chart Example8-6
8.2 LOW-LEVEL SIGNIFICANT WEATHER (SIGWX) CHARTS8-7
Figure 8-10. 12-Hour Low-Level SIGWX Chart Example8-7
8.2.1 Content8-7
Figure 8-11. Low-Level SIGWX Chart Symbols8-8
8.2.1.1 F lying Categories8-8
Figure 8-12. Low-Level SIGWX Chart Flying Categories Example8-8
8.2.1.2 Turbulence8-8
Figure 8-13. Low-Level SIGWX Chart Turbulence Forecast Example8-9
8.2.1.3 Freezing Levels .............................................................................................................................................. 8- 10
Figure 8-14. Low-Level SIGWX Chart Freezing Level Forecast Example8-10
Figure 8-15. Low-Level SIGWX Chart Multiple Freezing Levels Example8-10
8.2.2 Issuance8-11
Table of Contents xiii
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
Table 8-2. Low-Level SIGWX Chart Issuance Schedule8-11
8.2.3 Use8-11
Figure 8-16. 12-Hour Low-Level SIGWX Chart Example8-11
Figure 8-17. 24-Hour Low-Level SIGWX Chart Example8-12
8.3 MID-LEVEL SIGNIFICANT WEATHER (SIGWX) CHART8-13
Figure 8-18. Mid-Level SIGWX Chart Example8-13
8.3.1 Content8-13
8.3.1.1 Thunderstorms8-13
Table 8-3. Mid-Level SIGWX Chart Cumulonimbus Coverage8-14
Figure 8-19. Mid-Level SIGWX Chart Thunderstorm Examples8-14
8.3.1.2 Jet Streams8-15
Figure 8-21. Mid-Level SIGWX Chart Jet stream Example8-15
8.3.1.3 Tropopause Heights8-15
Figure 8-22. Mid-Level SIGWX Chart Tropopause Height Examples8-15
8.3.1.4 Tropical Cyclones8-16
Figure 8-23. Mid-Level SIGWX Chart Tropical Cyclone Examples8-16
8.3.1.5 Moderate or Severe Icing8-16
Figure 8-24. Mid-Level SIGWX Chart Icing Examples8-16
8.3.1.6 Moderate or Severe Turbulence (in cloud or in clear air)8-16
Figure 8-25. Mid-Level SIGWX Chart Turbulence Examples8-17
8.3.1.7 Cloud Coverage (non-cumulonimbus)8-17
Table 8-4. M id-Level SIGWX Chart Cloud Coverage (Non-Cumulonimbus)8-17
8.3.1.8 Cloud Type8-17
Table 8-5. Mid-Level SIGWX Chart Cloud Types8-18
Figure 8-26. Mid-Level SIGWX Chart – Example of Moderate or Severe Icing, Moderate or
Severe Turbulence (in Cloud or in Clear Air), Clouds, and Cloud Types8-18
8.3.1.9 Volcanic Eruptions ......................................................................................................................................... 8- 18
Figure 8-27. Mid-Level SIGWX Chart Volcanic Eruption Example8-18
8.3.1.10 Release of Radioactive Materials .................................................................................................................... 8- 19
Figure 8-28. Mid-Level SIGWX Chart Release of Radioactive Materials Example8-19
8.3.2 Issuance8-19
Table 8-6. Mid-Level SIGWX Chart Issuance Schedule .................................................................... 8- 19
8.3.3 Use8-19
Figure 8-29. Mid-Level SIGWX Chart Example8-20
8.4 HIGH-LEVEL SIGNIFICANT WEATHER (SIGWX) CHARTS8-21
Figure 8-30. High-Level SIGWX Chart Example8-21
8.4.1 Content8-22
8.4.1.1 Thunderstorms and Cumulonimbus Clouds8-22
Figure 8-31. High-Level SIGWX Chart Thunderstorm and Cumulonimbus Cloud Examples8-22
8.4.1.2 Moderate or Severe Turbulence8-23
Figure 8-32. High-Level SIGWX Chart Turbulence Examples8-23
8.4.1.3 Moderate or Severe Icing8-23
8.4.1.4 Jet Streams8-23
Figure 8-33. High-Level SIGWX Chart Jet stream Example8-24
8.4.1.5 T ropopause Heights8-24
Figure 8-35. High-Level SIGWX Chart Tropopause Height Examples8-24
8.4.1.6 Tropical Cyclones8-24
Figure 8-36. High Level SIGWX Chart Tropical Cyclone Examples8-25
8.4.1.7 Severe Squall Lines8-25
Figure 8-37. High-Level SIGWX Chart Severe Squall Line Example8-25
8.4.1.8 Volcanic Eruption Sites8-25
Figure 8-38. High-Level SIGWX Chart Volcanic Eruption Site Example8-26
8.4.1.9 Widespread Sandstorms and Dust storms8-26
Figure 8-39. High-Level SIGWX Chart Widespread Sandstorm and Dust Storm Example8-26
8.4.2 Issuance8-26
Table 8-7. High-Level SIGWX Chart Issuance Schedule – WAFC Washington8-27
8.4.3 Use8-28
Figure 8-40. High-Level SIGWX Chart – ICAO Area A Example8-28
Figure 8-41. High-Level SIGWX Chart – ICAO Area B1 Example8-29
Figure 8-42. High-Level SIGWX Chart – ICAO Area F Example8-29
Figure 8-43. High-Level SIGWX Chart – ICAO Area H Example8-30
Table of Contents xiv
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014)
Figure 8-44. High-Level SIGWX Chart – ICAO Area I Example8-30
Figure 8-45. High-Level SIGWX Chart – ICAO Area J Example8-31
Figure 8-46. High-Level SIGWX Chart – ICAO Area M Example8-31
9 NEW GENERATION WEATHER PRODUCTS9-1
9.1 COLLABORATIVE CONVECTIVE FORECAST PRODUCT (CCFP)9-1
Figure 9-1. CCFP Example9-1
9.1.1 Issuance9-2
9.1.2 Collaboration9-2
9.1.3 Content9-2
9.1.3.1 Coverage9-2
Figure 9-2. CCFP Forecast Convective Coverage9-3
9.1.3.2 Confidence9-3
9.1.3.3 Movement ........................................................................................................................................................ 9.3
Figure 9-3. CCFP Forecast Convective Movement9-3
9.1.3.4 Data Block9-4
Figure 9-4. CCFP Data Block9-4
Figure 9-5. CCFP Data Block Example9-4
TOPS9-4
Table 9-1. CCFP Tops9-4
Growth9-5
Table 9-2. CCFP Growth9-5
Confidence9-5
Table 9-3. CCFP Confidence9-5
Coverage9-5
Table 9-4. CCFP Coverage9-5
9.1.4 Strengths and Limitations9-5
9.1.5 Use9-6
9.2 EXTENDED CONVECTIVE FORECAST PRODUCT (ECFP)9-6
9.2.1 Issuance9-6
Figure 9-6. ECFP Example9-7
9.2.2 Content9-7
9.2.3 Use9-8
9.2.4 Frequency9-8
9.3 NATIONAL CONVECTIVE WEATHER FORECAST (NCWF)9-9
9.3.1 Issuance9-9
9.3.2 Content9-9
Figure 9-7. NCWF Example9-9
9.3.2.1 Current Convective Hazard Fields9-9
Figure 9-8. NCWF Current Convective Hazard Fields Example9-9
Convective Hazard Field Scale ............................................................................................................... 9- 10
Figure 9-9. NCW F Hazard Scale9-10
9.3.2.2 One-Hour Extrapolated Forecast Polygons ..................................................................................................... 9- 10
9.3.2.3 Forecast Speed and Direction ......................................................................................................................... 9- 10
9.3.2.4 Echo Tops....................................................................................................................................................... 9- 10 Figure 9-10. NCWF One-Hour Extrapolated Forecast Polygon, Forecast Movement Velocity,
and Echo Tops Example9-11
9.3.2.5 Previous Performance Polygons ..................................................................................................................... 9- 11
Figure 9-11. NCWF Previous Performance Polygons Example9-12
9.3.3 Strengths and Limitations9-12
9.3.4 Uses of the NCWF9-13
9.4 CURRENT AND FORECAST ICING PRODUCTS (CIP/FIP)9-13
9.4.1 Issuance9-13
9.4.2 Content9-13
9.4.2.1 Icing Probability9-14
Figure 9-12. CIP/FIP Icing Probability (3,000 feet MSL) Example9-15
9.4.2.2 Icing Probability – Maximum ......................................................................................................................... 9- 15
Figure 9-13. CIP/FIP Icing Probability – Max Example9-16
Table of Contents xv
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014)
9.4.2.3 Icing Severity ................................................................................................................................................. 9- 16
Figure 9-14. CIP/FIP Icing Severity (3,000 feet MSL) Example9-17
9.4.2.4 Icing Severity – Maximum ............................................................................................................................. 9- 17
Figure 9-15. CIP/FIP Icing Severity – Max Example9-18
9.4.2.5 Icing Severity – Probability > 25 Percent ....................................................................................................... 9- 18
Figure 9-16. CIP/FIP Icing Severity Probability >25 Percent Example9-19
9.4.2.6 Icing Severity – Probability > 25 Percent – Maximum ................................................................................... 9- 19
Figure 9-17. CIP/FIP Icing Severity Probability >25 Percent Example9-20
9.4.2.7 Icing Severity – Probability > 50 Percent ....................................................................................................... 9- 20
Figure 9-18. CIP/FIP Icing Severity Probability > 50 Percent Example9-21
9.4.2.8 Icing Severity – Probability > 50 Percent – Maximum ................................................................................... 9- 21
Figure 9-19. CIP/FIP Icing Severity Probability > 50 Percent - Max Example9-22
9.4.2.9 Icing Severity Plus Supercooled Large Drops (SLD) ...................................................................................... 9- 22
Figure 9-20. CIP/FIP Icing Severity Plus Supercooled Large Drops (SLD) Example9-23
9.4.2.10 Icing Severity Plus Supercooled Large Drops (SLD) – Maximum ................................................................ 9- 23
Figure 9-21. CIP/FIP Icing Severity Plus Supercooled Large Droplets (SLD) – Max Example9-24
9.4.3 Strengths and Limitations9-25
9.4.3.1 Strengths9-25
9.4.3.2 Limitations9-25
9.4.4 Uses9-25
9.5 GRAPHICAL TURBULENCE GUIDANCE (GTG2)9-26
9.5.1 Issuance9-26
9.5.2 Content9-26
9.5.2.1 GTG Analysis and Forecast9-26
Figure 9-22. GTG Example9-27
9.5.2.2 GTG Composite Analysis and Forecast .......................................................................................................... 9- 27
Figure 9-23. GTG Composite Example9-28
9.5.3 Strengths and Limitations9-28
9.5.3.1 Strengths9-28
9.5.3.2 Limitations9-29
9.5.4 Use9-29
9.6 METEOROLOGICAL IMPACT STATEMENT (MIS)9-30
9.6.1 Valid Period9-30
9.6.2 MIS Criteria9-30
9.6.3 MIS Issuance9-31
9.6.4 Format9-31
Figure 9-24. Meteorological Impact Statement (MIS) Decoding Example9-31
Table 9-5. Meteorological Impact Statement (MIS) – Decoding9-31
9.6.5 Examples9-32
Figure 9-25. Center Weather Service Unit (CWSU) Areas of Responsibility – CONUS9-33
Figure 9-26. CWSU Anchorage, AK (PAZA) Area of Responsibility9-33
9.7 CEILING AND VISIBILITY ANALYSIS (CVA)9-35
9.7.1 Issuance9-35
9.7.2 Content9-35
9.7.2.1 CVA Ceiling Analysis9-35
Figure 9-27. CONUS Display of CVA Ceiling Analysis9-36
Figure 9-28. Regional Display of CVA Ceiling Analysis9-36
9.7.2.2 CVA Visibility Analysis9-37
Figure 9-29. Regional Display of CVA Visibility Analysis ................................................................. 9- 37
9.7.2.3 CVA Flight Category Analysis ....................................................................................................................... 9- 37
Figure 9-30. Regional Display of CVA Flight Category Analysis9-38
9.7.3 Strengths and Limitations9-38
9.7.3.1 CVA Strengths9-38
9.7.3.2 CVA Limitations9-39
9.7.4 Use9-39
APPENDIX A: DEFINITION OF COMMON TERMS USED IN EN ROUTE FORECASTS AND
ADVISORIES10-1
Table A-1. Definition of Common Terms Used in En route Forecasts and Advisories10-1
Table of Contents xvi
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2014)
APPENDIX B: CONTRACTIONS AND ACRONYMS11-1
APPENDIX C: STANDARD CONVERSION CHART12-1
Figure C-1. Standard Conversion Chart12-1
APPENDIX D: DENSITY ALTITUDE CALCULATION13-1
Figure D-1. Density Altitude Computation Chart13-1
APPENDIX E: INTERNET LINKS14-1
Table E-1. Selected National Weather Service (NWS) Links14-1
Table E-2. Selected Federal Aviation Administration (FAA) Links14-1
Table E-3. Selected Links to Aviation Weather Products14-2
APPENDIX F: AWC ADVISORY PLOTTING CHART15-1
Figure F-1. AWC Advisory Plotting Chart15-1
Table F-1. AWC Advisory Plotting Chart Reference Points15-2
APPENDIX G: WSR-88D WEATHER RADAR NETWORK16-1
Figure G-1. WSR-88D Weather Radar Network Sites16-1
Table G-1. WSR-88D Weather Radar Network16-2
APPENDIX H: AWC GEOGRAPHICAL AREA DESIGNATOR MAP17-1
Figure H-1. AWC Geographical Area Designator Map17-1
APPENDIX I: PRESENT WEATHER SYMBOLS18-1
Figure I-1. Present Weather Symbols with Text Explanation18-1
Figure I-2. Present Weather Symbols with Corresponding METAR/SPECI
Present Weather Code18-2
APPENDIX J: TURBULENCE AND ICING INTENSITY DEPICTIONS19-1
Table J-1. Turbulence Intensity19-1
Table J-2. Icing Intensity19-1
Table of Contents xvii