Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009) NOTE: CLICK ON ANY ENTRY IN THE OF THE TABLE OF CONTENTS TO JUMP
DIRECTLY TO THAT SECTIONXVI
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
1.1.1.1 Satellite Analysis Branch (SAB)1-1
1.1.2 National Weather Service (NWS)1-1
1.1.2.1 National Centers for Environmental Prediction (NCEP)1-1
1.1.2.1.1 NCEP Central Operations (NCO)1-2
1.1.2.1.2 Aviation Weather Center (AWC)1-2
1.1.2.1.3 Hydrometeorological Prediction Center (HPC)1-2
1.1.2.1.4 Storm Prediction Center (SPC)1-2
1.1.2.1.5 Tropical Prediction Center (TPC)1-2
1.1.2.2 Alaskan Aviation Weather Unit (AAWU)1-2
1.1.2.3 Center Weather Service Unit (CWSU)1-3
1.1.2.4 Weather Forecast Office (WFO)1-3
1.1.2.5 NWS Office at the FAA Academy1-3
1.2 FEDERAL AVIATION ADMINISTRATION (FAA)1-4
1.2.1 Air Traffic Control System Command Center (ATCSCC)1-4
1.2.2 Air Route Traffic Control Center (ARTCC)1-4
1.2.3 Air Traffic Control Tower (ATCT) and Terminal Radar Approach Control (TRACON)1-4
1.2.4 Flight Service Station (FSS) / Automated Flight Service Station (AFSS)1-5
1.3 DISSEMINATION OF AVIATION WEATHER PRODUCTS1-6
1.3.1 Weather Briefings1-6
1.3.1.1 Standard Briefing1-6
1.3.1.2 Abbreviated Briefing1-7
1.3.1.3 Outlook Briefing1-7
1.3.2 Direct Use Access Terminal Service (DUATS/DUAT)1-7
1.3.3 Aviation Digital Data Service (ADDS)1-8
1.3.4 Telephone Information Briefing Service (TIBS)1-8
1.3.5 Hazardous Inflight Weather Advisory Service (HIWAS)1-9
1.3.6 En Route Flight Advisory Service (EFAS)1-10
1.3.7 Automatic Dependent Surveillance – Broadcast (ADS-B)1-11
1.3.7.1 Flight Information Service – Broadcast (FIS-B)1-11
1.3.7.1.1 FIS-B Products1-11
1.3.7.1.2 Operational Use of FIS-B Products1-12
2 AVIATION WEATHER PRODUCT CLASSIFICATION AND POLICY2-1
2.1 CLASSIFICATION OF AVIATION WEATHER PRODUCTS2-1
2.1.1 Primary Weather Product Classification2-1
2.1.2 Supplementary Weather Product Classification2-1
2.2 TYPES OF AVIATION WEATHER INFORMATION2-2
2.2.1 Observations2-2
2.2.2 Analysis2-2
2.2.3 Forecasts2-2
2.3 CATEGORIZING AVIATION WEATHER SOURCES2-2
2.3.1 Federal Government2-2
2.3.2 Enhanced Weather Information System (EWINS)2-3
2.3.3 Commercial Weather Information Providers2-3
3 OBSERVED TEXT PRODUCTS3-1
3.1 AVIATION ROUTINE WEATHER REPORTS (METAR) AND AVIATION SELECTED SPECIAL WEATHER
REPORTS (SPECI)3-1
3.1.1 Aviation Routine Weather Report (METAR)3-1
3.1.2 Aviation Selected Special Weather Report (SPECI)3-1
Table 3-1. SPECI Criteria3-2
AC 00-45F, CHG 2 Table of Contents Page i
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
3.1.3 Format3-3
Figure 3-1. METAR/SPECI Coding Format3-3
3.1.3.1 Type of Report3-3
3.1.3.2 Station Identifier3-3
Figure 3-2. ICAO Continent codes3-4
3.1.3.3 Date and Time of Report3-5
3.1.3.4 Report Modifier (As Required)3-5
3.1.3.5 Wind Group3-6
3.1.3.5.1 Wind Gust3-6
3.1.3.5.2 Variable Wind Direction (speed 6 knots or less)3-6
3.1.3.5.3 Variable Wind Direction (speed greater than 6 knots)3-6
3.1.3.5.4 Calm Wind3-7
3.1.3.6 Visibility Group3-7
3.1.3.7 Runway Visual Range (RVR) Group3-7
3.1.3.8 Present Weather Group3-8
Table 3-2. METAR/SPECI Notations for Reporting Present Weather13-9
3.1.3.8.1 Intensity Qualifier3-10
3.1.3.8.2 Proximity Qualifier3-10
3.1.3.8.3 Descriptor Qualifier3-10
3.1.3.8.4 Precipitation3-11
3.1.3.8.5 Obscuration3-11
3.1.3.8.6 Other Weather Phenomena3-11
3.1.3.9 Sky Condition Group3-12
Figure 3-3. Obscuration Effects on Slant Range Visibility3-12
Table 3-3. METAR/SPECI Contractions for Sky Cover3-13
Table 3-4. METAR/SPECI Increments of Reportable Values of Sky Cover Height3-13
Figure 3-4. METAR/SPECI Sky Condition Coding3-14
3.1.3.10 Temperature/Dew Point Group3-15
3.1.3.11 Altimeter3-15
3.1.3.12 Remarks (RMK)3-15
Table 3-5. METAR/SPECI Order of Remarks3-16
3.1.3.13 Automated, Manual, and Plain Language Remarks3-17
3.1.3.13.1 Volcanic Eruptions (Plain Language)3-17
3.1.3.13.2 Funnel Cloud3-17
3.1.3.13.3 Type of Automated Station3-17
3.1.3.13.4 Peak Wind3-17
3.1.3.13.5 Wind Shift3-18
3.1.3.13.6 Tower or Surface Visibility3-18
3.1.3.13.7 Variable Prevailing Visibility3-18
3.1.3.13.8 Sector Visibility (Plain Language)3-18
3.1.3.13.9 Visibility at Second Location3-18
3.1.3.13.10 Lightning3-18
Table 3-6. METAR/SPECI Type and Frequency of Lightning3-19
3.1.3.13.11 Beginning and Ending of Precipitation3-19
3.1.3.13.12 Beginning and Ending of Thunderstorms3-19
3.1.3.13.13 Thunderstorm Location (Plain Language)3-19
3.1.3.13.14 Hailstone Size (Plain Language)3-19
3.1.3.13.15 Virga (Plain Language)3-20
3.1.3.13.16 Variable Ceiling Height3-20
3.1.3.13.17 Obscurations (Plain Language)3-20
3.1.3.13.18 Variable Sky Condition (Plain Language)3-20
3.1.3.13.19 Significant Cloud Types (Plain Language)3-20
3.1.3.13.19.1 Cumulonimbus or Cumulonimbus Mammatus3-20
Figure 3-5. Cumulonimbus (CB) Example3-21
Figure 3-6. Cumulonimbus Mammatus (CBMAM) Example3-21
3.1.3.13.19.2 Towering Cumulus3-22
Figure 3-7. Towering Cumulus (TCU) Example3-22
3.1.3.13.19.3 Altocumulus Castellanus3-23
Figure 3-8. Altocumulus Castellanus (ACC) Example3-23
3.1.3.13.19.4 Standing Lenticular or Rotor Clouds3-24
Figure 3-9. Standing Lenticular and Rotor Clouds Example3-24
3.1.3.13.20 Ceiling Height at Second Location3-24
AC 00-45F, CHG 2 Table of Contents Page ii
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
3.1.3.13.21 Pressure Rising or Falling Rapidly3-25
3.1.3.13.22 Sea-Level Pressure3-25
3.1.3.13.23 Aircraft Mishap (Plain Language)3-25
3.1.3.13.24 No SPECI Reports Taken (Plain Language)3-25
3.1.3.13.25 Snow Increasing Rapidly3-25
3.1.3.13.26 Other Significant Information (Plain Language)3-25
3.1.3.14 Additive and Automated Maintenance Data3-25
3.1.3.14.1 Hourly Temperature and Dew Point3-25
3.1.3.14.2 Maintenance Data Groups3-26
3.1.3.14.2.1 Sensor Status Indicators3-26
3.1.3.14.2.2 Maintenance Indicator3-26
3.1.4 METAR/SPECI Examples3-27
3.2 PILOT WEATHER REPORTS (PIREP)3-32
3.2.1 Format3-32
Figure 3-10. Pilot Weather Report (PIREP) Coding Format3-32
3.2.1.1 Message Type (UUA/UA)3-32
3.2.1.1.1 Urgent PIREPs3-32
3.2.1.1.2 Routine PIREPs3-33
3.2.1.2 Location (/OV)3-33
3.2.1.2.1 Location3-33
3.2.1.2.1.1 3.2.1.3.1.1 Route Segment3-33
3.2.1.3 Time (/TM)3-34
3.2.1.4 Altitude/Flight Level (/FL)3-34
3.2.1.5 Aircraft Type (/TP)3-34
3.2.1.6 Sky Condition (/SK)3-34
3.2.1.7 Flight Visibility and Weather (/WX)3-35
Table 3-7. PIREP Weather Type and Symbols3-36
3.2.1.8 Air Temperature (/TA)3-38
3.2.1.9 Wind Direction and Speed (/WV)3-38
3.2.1.10 Turbulence (/TB)3-38
Table 3-8. PIREP Turbulence Reporting Criteria3-39
3.2.1.11 Icing (/IC)3-39
Table 3-9. Icing Intensities, Contractions, and Airframe Ice Accumulation3-40
Table 3-10. Icing Types, Contractions, and Descriptions3-40
3.2.1.12 Remarks (/RM)3-40
3.2.1.12.1 Wind Shear3-41
3.2.1.12.2 FUNNEL CLOUD, TORNADO, and WATERSPOUT3-41
3.2.1.12.3 Thunderstorm3-41
3.2.1.12.4 Lightning3-41
3.2.1.12.5 Electrical Discharge3-41
3.2.1.12.6 Clouds3-42
3.2.1.12.7 Plain Language3-42
3.2.1.12.8 Volcanic Eruptions3-42
3.2.1.12.9 SKYSPOTTER3-42
3.2.2 PIREP Examples3-43
3.3 RADAR WEATHER REPORT (SD/ROB)3-45
Figure 3-11. Radar Weather Report (SD/ROB) Coding Format3-45
3.3.1 Format3-45
3.3.1.1 Location Identifier3-45
3.3.1.2 Time3-45
3.3.1.3 Configuration3-45
Figure 3-12. Radar Weather Report (SD/ROB) Configurations3-46
3.3.1.4 Coverage3-46
3.3.1.5 Precipitation Type3-46
3.3.1.6 Precipitation Intensity3-47
Table 3-11. SD/ROB Reportable Intensities3-47
3.3.1.7 Location3-47
Figure 3-13. SD/ROB AREA, Line (LN), and CELL Location Examples3-48
3.3.1.8 Maximum Top3-48
3.3.1.9 Cell Movement3-48
3.3.1.10 Remarks3-49
AC 00-45F, CHG 2 Table of Contents Page iii
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
Table 3-12. Weather Radar Report Remarks and Meaning3-49
3.3.1.11 Digital Section3-49
Figure 3-14. SD/ROB Digital Section Information Plotted on a PPI Grid Overlay Example3-50
3.3.2 Examples3-50
Figure 3-15. WSR-88D Weather Radar Network Sites3-52
4 RADAR AND SATELLITE IMAGERY4-1
4.1 RADAR4-1
4.1.1 Description4-1
4.1.2 Modes of Operation4-1
4.1.2.1 Clear Air Mode4-1
4.1.2.2 Precipitation Mode4-1
4.1.3 Echo Intensities4-2
Figure 4-1. WSR-88D Weather Radar Echo Intensity Legend4-2
Table 4-1. WSR-88D Weather Radar Precipitation Intensity Terminology4-2
4.1.4 Products4-3
4.1.4.1 Base Reflectivity4-3
Figure 4-2. WSR-88D Weather Radar Short Range (124 NM) Base Reflectivity Product Example
.4-3
Figure 4-3. WSR-88D Weather Radar Long Range (248 NM) Base Reflectivity Product Example 4- 4
4.1.4.1.1 Base Reflectivity Use4-4
Figure 4-4. WSR-88D Weather Radar Stratiform Precipitation on the 0.5ºBase Reflectivity
Product Example4-5
Figure 4-5. WSR-88D Weather Radar Convective Precipitation on the 0.5ºBase Reflectivity
Product Example4-5
4.1.4.1.2 Strengths of Base Reflectivity4-6
4.1.4.1.3 Limitations of Base Reflectivity4-6
4.1.4.1.3.1 Radar Beam Overshooting4-6
4.1.4.1.3.2 Beam Blockage4-6
Figure 4-6. WSR-88D Weather Radar Beam Blockage on Base Reflectivity Product Example4-7
4.1.4.1.3.3 Ground Clutter4-7
Figure 4-8. WSR-88D Weather Radar Ground Clutter Example4-7
4.1.4.1.3.4 Ghost4-8
Figure 4-9. WSR-88D Weather Radar Ghost Example4-8
4.1.4.1.3.5 Angels4-8
Figure 4-10. WSR-88D Weather Radar Angle Example4-9
4.1.4.1.3.6 Anomalous Propagation (AP)4-9
Figure 4-11. WSR-88D Weather Radar Anomalous Propagation (AP) Example4-10
4.1.4.2 Composite Reflectivity4-10
Figure 4-12. Creation of a Composite Reflectivity product4-10
Figure 4-13. WSR-88D Weather Radar Long Range (248 NM) Composite Reflectivity Product
Example4-11
Figure 4-14. WSR-88D Weather Radar Short Range (124 NM) Composite Reflectivity Product
Example4-12
4.1.4.2.1 Composite Reflectivity Use4-12
Figure 4-15. WSR-88D Weather Radar 0.5º Base Reflectivity versus Composite Reflectivity
Comparison4-13
4.1.4.2.2 Strengths of Composite Reflectivity4-13
4.1.4.2.3 Limitations of Composite Reflectivity4-13
4.1.4.2.3.1 Radar Beam Overshooting4-13
4.1.4.2.3.2 Beam Blockage4-13
4.1.4.2.3.3 Ground Clutter4-14
4.1.4.2.3.4 Ghost4-14
4.1.4.2.3.5 Angels4-14
4.1.4.2.3.6 Anomalous Propagation (AP)4-14
4.1.5 Radar Mosaics4-14
4.1.5.1 0.5º Mosaics - Contiguous U.S. and Hawaii4-15
Table 4-2. NWS Radar Mosaic Products4-15
Figure 4-16. Great Lakes Regional Radar Mosaic Example4-15
4.1.5.2 0.5º Mosaics - Alaska4-16
AC 00-45F, CHG 2 Table of Contents Page iv
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
Figure 4-17. Alaskan Regional Radar Mosaic Example4-16
4.2 SATELLITE4-17
4.2.1 Description4-17
4.2.2 Imagery Types4-17
4.2.2.1 Visible Imagery4-17
Figure 4-18. Visible Satellite Image – U.S. Example4-18
Figure 4-19. Visible Satellite Image – Regional-Scale Example4-19
4.2.2.1.1 Visible Image Data Legend4-19
Figure 4-20. Visible Satellite Data Legend4-19
4.2.2.2 Infrared (IR) Imagery4-19
Figure 4-21. Infrared (Color) Satellite Image – U.S. Example4-20
Figure 4-22. Infrared (Color) Satellite Image – Regional-Scale Example4-21
Figure 4-23. Unenhanced Infrared (black and white) Satellite Image – U.S. Example4-21
Figure 4-24. Unenhanced Infrared (black and white) Satellite Image – Regional- Scale Example . 4- 22
4.2.2.2.1 Infrared Image Data Legends4-22
Figure 4-25. Infrared (Color) Satellite Image Data Legend4-22
Figure 4-26. Unenhanced Infrared (black and while) Satellite Image Data Legend4-22
4.2.3.3 Water Vapor Imagery4-22
Figure 4-27. Water Vapor Satellite Image – U.S. Example4-23
Figure 4-28. Water Vapor Satellite Image – Regional-Scale Example4-24
4.2.3.3.1 Water Vapor Image Data Legend4-24
Figure 4-29. Water Vapor Satellite Image Data Legend4-24
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
5.1.2.3.1 Station Identifier5-4
5.1.2.3.2 Temperature5-4
5.1.2.3.3 Dew Point5-5
5.1.2.3.4 Weather5-5
Figure 5-6. HPC Surface Analysis Chart Common Weather Symbols5-5
5.1.2.3.5 Wind5-5
Figure 5-7. HPC Surface Analysis Chart Wind Plotting Model5-6
5.1.2.3.6 Ceiling5-6
5.1.2.3.7 Visibility5-6
5.1.2.3.8 Pressure5-6
5.1.2.3.9 Pressure Trend5-6
Figure 5-8. HPC Surface Analysis Chart Pressure Trends5-7
5.1.2.3.10 Sky Cover5-7
Figure 5-9. HPC Surface Analysis Chart Sky Cover Symbols5-7
5.1.2.3.11 Water Temperature5-7
5.1.2.3.12 Swell Information5-8
5.1.2.3.13 Wave Information5-8
5.1.2.4 Analyses5-8
5.1.2.4.1 Isobars5-8
5.1.2.4.2 Pressure Systems5-9
5.1.2.4.3 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
AC 00-45F, CHG 2 Table of Contents Page v
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009) Figure 5-13. HPC Surface Analysis Chart for Aviation Interests – Contiguous U.S. Example ... 5-11 Figure 5-14. HPC Surface Analysis Chart for Aviation Interests – South central U.S. Example 5-11
5.1.3 OPC and WFO Honolulu Surface Analysis Charts5-12
5.1.3.1 Issuance5-12
Table 5-2. OPC and WFO Honolulu Surface Analysis Charts Issuance Schedule5-12
5.1.3.2 Analysis Symbols5-12
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 Information5-13
5.1.3.4 Analyses5-13
5.1.3.4.1 Isobars5-13
5.1.3.4.2 Pressure Systems5-14
5.1.3.4.3 Fronts5-14
5.1.4 TPC Surface Analysis Charts5-14
5.1.4.1 Issuance5-14
Table 5-3. TPC Surface Analysis Charts Issuance Schedule5-14
5.1.4.2 Analysis Symbols5-14
Figure 5-17. TPC Surface Analysis Chart Symbols5-15
Figure 5-18. TPC Tropical Surface Analysis Chart Example5-15
5.1.4.2.1 Wind5-15
Figure 5-19: TPC Surface Analysis Chart Wind Plotting Model5-16
5.1.4.3 Analyses5-16
5.1.4.3.1 Isobars5-16
5.1.4.3.2 Pressure Systems5-16
5.1.4.3.3 Fronts5-17
5.1.5 Unified Surface Analysis Chart5-17
5.1.5.1 Issuance5-17
Table 5-4. Unified Surface Analysis Chart Issuance Schedule5-17
Figure 5-20. Unified Surface Analysis Chart Example5-17
5.1.5.2 Analysis Symbols5-17
Figure 5-21. Unified Surface Analysis Chart Symbols5-18
5.1.5.3 Analyses5-18
5.1.5.3.1 Isobars5-18
5.1.5.3.2 Pressure Systems5-18
5.1.5.3.3 Fronts5-18
5.1.6 AAWU Surface Charts5-19
5.1.6.1 Issuance5-19
Table 5-5. AAWU Surface Analysis Issuance Schedule5-19
5.1.6.2 Analysis Symbols5-19
Figure 5-22. AAWU Surface Analysis Chart Symbols5-19
Figure 5-23. AAWU Alaskan Surface Chart Example5-20
5.1.6.3 Station Plot Models5-20
Figure 5-24. AAWU Surface Analysis Chart Station Plot Model5-20
Figure 5-25. AAWU Surface Analysis Chart Ship/buoy Plot Model5-21
5.1.6.3.1 Station Identifier5-21
5.1.6.3.2 Temperature5-21
5.1.6.3.3 Dew Point5-21
5.1.6.3.4 Wind5-21
Figure 5-26: AAWU Surface Analysis Chart Wind Plotting Model5-22
5.1.6.3.5 Ceiling5-22
5.1.6.3.6 Visibility5-22
5.1.6.3.7 Pressure5-22
5.1.6.3.8 Pressure Trend5-22
Figure 5-27. AAWU Surface Analysis Chart Pressure Trends5-23
5.1.6.3.9 Sky Cover5-23
Figure 5-28. AAWU Surface Analysis Chart Sky Cover Symbols5-23
5.1.6.3.10 Water Temperature5-23
5.1.6.3.11 Swell Information5-24
5.1.6.3.12 Wave Information5-24
5.1.6.4 Analyses5-24
5.1.6.4.1 Isobars5-24
5.1.6.4.2 Pressure Systems5-24
AC 00-45F, CHG 2 Table of Contents Page vi
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
5.1.6.4.3 Fronts5-25
5.2 CONSTANT PRESSURE CHARTS5-26
Figure 5-29. Constant Pressure Chart Example5-26
5.2.1 Issuance5-26
5.2.2 Observational Data5-26
Figure 5-30. U.S. Radiosonde Network5-27
Table 5-6 Features of Constant Pressure Charts5-28
Table 5-7. Constant Pressure Chart Plotting Models5-28
Table 5-8. Radiosonde Plotting Model Examples5-29
5.2.3 Analyses5-29
5.2.3.1 Height5-29
5.2.3.2 Temperature5-29
5.2.3.3 Wind Speed5-30
5.2.3.4 Use5-30
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 Example5-32
Figure 5-32. 700MB Analysis Chart Example5-32
Figure 5-33. 500MB Analysis Chart Example5-33
Figure 5-34. 300MB Analysis Chart Example5-33
Figure 5-35. 200MB Analysis Chart Example5-34
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. ADDS Freezing Level Graphic Example5-38
5.4 LIFTED INDEX ANALYSIS CHART5-39
Figure 5-38. Lifted Index Analysis Chart Example5-39
5.4.1 Issuance5-39
5.4.2 Lifted Index (LI)5-39
5.4.2.1 Data Plot5-40
5.4.2.2 Analysis5-40
5.4.2.3 Use of Lifted Index5-40
5.4.3 K Index5-40
5.4.3.1 Data Plot5-40
5.4.3.2 Use of K Index5-40
Table 5-12. K Index and Coverage of General Thunderstorms5-41
5.5 WEATHER DEPICTION CHART5-42
Figure 5-39. Weather Depiction Chart Example5-42
5.5.1 Issuance5-42
Table 5-13. Weather Depiction Charts Issuance Schedule5-42
5.5.2 Station Plot Model5-42
Figure 5-40. Weather Depiction Chart Station Plot Model5-43
5.5.2.1 Visibility5-43
5.5.2.2 Present Weather5-43
5.5.2.3 Sky Cover5-43
5.5.2.4 Ceiling5-43
5.5.3 Weather Flying Category Analysis5-44
5.5.4 Use5-44
5.6 ALASKA WEATHER DEPICTION CHARTS5-45
Figure 5-41. AAWU Alaska Weather Depiction Chart Example5-45
Table 5-14. AAWU Alaska Weather Depiction Charts Coverage5-46
5.6.1 Issuance5-46
5.6.2 Legends5-46
5.6.2.1 Flying Category5-46
Table 5-15 AAWU Alaska Weather Flying Categories and Criteria5-46
5.6.2.2 Station Plot5-46
AC 00-45F, CHG 2 Table of Contents Page vii
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
Figure 5-42. AAWU Alaska Weather Depiction Chart Station Plot Legend5-46
5.6.2.3 Sky Cover5-47
5.6.2.4 Station Identifier (STNID)5-47
5.6.2.5 Wind5-47
Figure 5-43. AAWU Alaska Weather Depiction Chart Wind Symbols5-47
5.6.2.6 Temperature (TMP deg F)5-47
5.6.2.7 Visibility (VIS)5-47
5.6.2.8 Dew Point Temperature (DEWPT deg F)5-48
5.6.2.9 Ceiling (CIG)5-48
5.6.2.10 Present Weather (WX)5-48
Table 5-16 Alaska Weather Depiction Charts Precipitation Symbols5-48
Table 5-17 Alaska Weather Depiction Charts Obstruction to Visibility Symbols5-48
Table 5-18 Alaska Weather Depiction Charts Precipitation Intensity Symbols5-48
5.6.3 Use5-49
Figure 5-44. AAWU Alaska Weather Depiction Chart – South Central Alaska Example5-49
5.7 RADAR SUMMARY CHART5-50
Figure 5-45. Radar Summary Chart Example5-50
5.7.1 Issuance5-50
5.7.2 Format5-50
5.7.2.1 Precipitation Type5-50
Table 5-19. Radar Summary Chart Precipitation Type Symbols5-51
5.7.2.2 Precipitation Intensity5-51
Figure 5-46. WSR-88D Weather Radar Network5-51
Figure 5-47. Radar Summary Chart Precipitation Intensity5-52
5.7.2.3 Echo Coverage5-52
5.7.2.4 Line Echoes5-52
Table 5-20. Radar Summary Chart Echo Configuration Symbols5-52
5.7.2.5 Cell Movement5-52
Table 5-21. Radar Summary Chart Cell Movement Examples5-53
5.7.2.6 Maximum Top5-53
Figure 5-48. Radar Summary Chart Maximum Top Example5-53
5.7.2.7 Weather Watch Areas5-54
Table 5-22. Radar Summary Chart Weather Watch Area Examples5-54
5.7.2.8 Operational Contractions5-54
Table 5-23. Radar Summary Chart Operational Contractions5-54
5.7.3 Use5-54
Figure 5-49. Radar Summary Chart Example5-55
5.8 ALASKA INITIAL GEOPOTENTIAL HEIGHTS AND WINDS CHARTS5-56
Figure 5-50. Alaskan Initial Geopotential Heights and Winds Chart Example5-56
Table 5-24. Pressure Altitudes of Alaska Initial Geopotential Heights and Winds Charts5-56
5.8.1 Issuance5-56
5.8.2 Analysis5-57
5.8.2.1 Height Contours5-57
5.8.2.2 Winds5-57
Figure 5-51. Alaskan Initial Geopotential Heights and Winds Chart Wind Plotting Model5-57
5.8.3 Use5-57
Figure 5-52. Alaskan Initial Geopotential Heights and Winds Chart - 200MB Winds and Contours
Chart Example5-59
Figure 5-53. Alaskan Initial Geopotential Heights and Winds Chart - 300MB Winds and Contours
Chart Example5-59
Figure 5-54. Alaskan Initial Geopotential Heights and Winds Chart - 500MB Winds and Contours
Chart Example5-60
Figure 5-55. Alaskan Initial Geopotential Heights and Winds Chart - 700MB Winds and Contours
Chart Example5-60
Figure 5-56. Alaskan Initial Geopotential Heights and Winds Chart - 850MB Winds and Contours
Chart Example5-61
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
AC 00-45F, CHG 2 Table of Contents Page viii
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
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
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 Format6-9
Figure 6-6. Convective SIGMET Decoding Example6-10
Table 6-2. Decoding a Convective SIGMET6-10
6.1.4.5 Convective SIGMET Outlook6-11
6.1.4.6 Convective SIGMET Cancellations6-11
6.1.4.7 Convective SIGMET Amendments6-11
6.1.4.8 Convective SIGMET Corrections6-11
6.1.4.9 Convective SIGMET Bulletin Examples6-11
6.1.4.9.1 Convective SIGMET Bulletin – Tropical Cyclone Example6-12
6.1.5 SIGMET – Outside the Conterminous U.S. (O-CONUS)6-13
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 Ash6-17
6.1.5.5 SIGMETs for Tropical Cyclone6-17
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
6.1.5.9.1 SIGMET for Volcanic Ash Example6-18
6.1.5.9.2 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 Schedule6-24
6.2.5 AIRMET Format6-25
Figure 6-11. AIRMET Bulletin Decoding Example6-26
Table 6-6. Decoding an AIRMET Bulletin6-26
6.2.5.1 AIRMET Updates and Amendments6-27
6.2.5.2 AIRMET Corrections6-27
6.2.6 AIRMET Examples6-27
6.2.6.1 CONUS AIRMET Example6-27
6.2.6.2 Hawaii AIRMET Example6-28
6.2.6.3 Alaska AIRMET Example6-29
AC 00-45F, CHG 2 Table of Contents Page ix
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
6.3 CENTER WEATHER ADVISORY (CWA)6-31
6.3.1 CWA Issuance6-31
Figure 6-12. Center Weather Service Unit (CWSU) Areas of Responsibility, Contiguous U.S. .. 6-31
Figure 6-13. CWSU Anchorage, AK (PAZA) Area of Responsibility6-32
6.3.2 CWA Communications Headers (UCWA / CWA)6-32
6.3.3 CWA Criteria6-32
6.3.4 CWA Format6-33
Figure 6-14. Center Weather Advisory (CWA) Decoding Example6-33
Table 6-7. Decoding a Center Weather Advisory (CWA)6-33
6.3.5 Examples6-34
6.4 ADDITIONAL PRODUCTS FOR CONVECTION6-37
6.4.1 Convective Outlooks (AC)6-37
6.4.1.1 Issuance6-37
Table 6-8. Convective Outlook Issuance Schedule6-37
Figure 6-15. Day 1 Categorical Convective Outlook Graphic Example6-38
6.4.1.2 Format of the Categorical Convective Outlook Narrative6-38
6.4.2 Watch Notification Messages6-39
6.4.2.1 Aviation Watch Notification Message6-39
6.4.2.1.1 Format of an Aviation Watch Notification Message6-39
Figure 6-16. Aviation Watch Notification Message Decoding Example6-40
Table 6-9. Decoding a Severe Weather Watch Bulletin6-40
6.4.2.1.2 Issuance6-41
6.4.3 Public Severe Thunderstorm Watch Notification Message6-41
6.4.3.1 Format of Public Severe Thunderstorm Watch Notification Message6-41
6.4.3.2 Example of a Public Severe Thunderstorm Watch Notification Message6-42
6.4.4 Public Tornado Watch Notification Message6-43
6.4.4.1 Format of a Public Tornado Watch Notification Message6-44
6.4.4.2 Example of a Public Tornado Watch Notification Message6-44
6.5 PRODUCTS FOR TROPICAL CYCLONES6-46
6.5.1 Aviation Tropical Cyclone Advisory (TCA)6-46
6.5.1.1 Issuance6-46
6.5.1.2 Content6-46
6.5.1.3 Format6-46
6.5.1.4 Aviation Tropical Cyclone Advisory (TCA) Example6-47
6.5.2 Tropical Cyclone Public Advisory (TCP)6-47
6.5.2.1 TCP Responsibility6-47
6.5.2.2 TCP Issuance6-48
Table 6-10. Tropical Cyclone Public Advisory Issuance Schedule6-48
6.5.2.2.1 TCP Intermediate Issuances6-49
Table 6-11. Intermediate Tropical Cyclone Public Advisory Issuance Schedule6-49
6.5.2.3 TCP Content6-49
6.5.2.4 TCP Format6-50
6.5.2.5 Tropical Storm Public Advisory (TCP) Example6-51
6.5.2.6 Hurricane/Typhoon Public Advisory Example6-51
6.5.2.7 Intermediate Public Advisory Example6-53
6.5.2.8 Special Public Advisory Example6-55
6.5.2.9 Public Advisory Correction Example6-56
6.6 VOLCANIC ASH ADVISORY PRODUCTS6-57
6.6.1 Volcanic Ash Advisory Center (VAAC)6-57
Figure 6-17. Volcanic Ash Advisory Centers (VAACs) Area of Responsibility6-57
6.6.2 Volcanic Ash Advisory Statement (VAAS)6-58
6.6.2.1 Issuance6-58
6.6.2.2 Format6-58
6.6.2.3 VAAS Issued by the Washington VAAC Example6-58
6.6.3 Volcanic Ash Advisory (VAA)6-59
6.6.3.1 VAA Issuance6-59
6.6.3.2 VAA Format6-59
6.6.3.3 Volcanic Ash Advisory (VAA) Example6-59
7 FORECAST TEXT PRODUCTS7-1
AC 00-45F, CHG 2 Table of Contents Page x
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
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 Header7-7
Figure 7-7. Area Forecast - Clouds and Weather Element Example7-8
7.1.6.1 Area Forecast – Conterminous U.S. (CONUS) Examples7-8
7.1.6.1.1 Area Forecast – BOS Example7-8
7.1.6.1.2 Area Forecast – SFO (FA) Example7-10
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)7-13
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
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
7.2.2.7.1 Exception for Encoding Multiple Precipitation Types7-23
7.2.2.7.2 Thunderstorm Descriptor7-24
7.2.2.7.3 Fog Forecast7-24
Table 7-5. TAF Fog Terms7-25
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)7-26
7.2.2.9.1 Cloud Group (NsNsNshshshs)7-26
Table 7-7. TAF Sky Cover7-26
7.2.2.9.2 Vertical Obscuration Group (VVhshshs)7-26
7.2.2.9.3 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
7.2.2.11.1 From (FM) Group (FMYYGGgg)7-28
7.2.2.11.2 TEMPO (YYGG/YeYeGeGe) Group7-29
7.2.2.11.3 PROB30 (YYGG/YeYeGeGe) Group7-30
7.2.2.12 TAF Examples7-31
7.2.3 Issuance7-33
Table 7-8. TAF Issuance Schedule7-33
7.2.3.1 Minimum Observational Requirements for Routine TAF Issuance and Continuation7-34
7.2.3.2 Sites with Scheduled Part-Time Observations7-34
7.2.3.2.1 Examples of Scheduled Part-Time Observations TAFs7-34
AC 00-45F, CHG 2 Table of Contents Page xi
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
7.2.3.3 Automated Observing Sites Requiring Part-Time Augmentation7-35
7.2.3.4 Non-Augmented Automated Observing Sites7-35
7.3 INTERNATIONAL AVIATION ROUTE FORECASTS (ROFOR)7-36
7.3.1 ROFOR Criteria7-36
7.3.2 Issuance7-36
7.3.2.1 ROFOR Amendments7-36
7.3.2.2 ROFOR Corrections7-36
7.3.3 ROFOR Content7-36
7.3.4 ROFOR Examples7-37
7.3.4.1 Majuro to Kwajalein Route ROFOR Example7-37
7.3.4.2 Tarawa to Majuro Route ROFOR Example7-37
7.3.4.3 Santa Barbara and San Francisco to Honolulu Route ROFOR Example7-37
7.4 WIND AND TEMPERATURE ALOFT FORECAST (FB)7-39
7.4.1 Forecast Altitudes7-39
Table 7-9. Wind and Temperature Aloft Forecast Levels7-39
7.4.2 Format7-39
7.4.2.1 Coding Example7-40
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 US7-42
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 Example8-7
8.2 LOW-LEVEL SIGNIFICANT WEATHER (SIGWX) CHARTS8-8
Figure 8-10. 12-Hour Low-Level SIGWX Chart Example8-8
8.2.1 Content8-8
Figure 8-11. Low-Level SIGWX Chart Symbols8-9
8.2.1.1 Flying Categories8-9
Figure 8-12. Low-Level SIGWX Chart Flying Categories Example8-9
8.2.1.2 Turbulence8-9
Figure 8-13. Low-Level SIGWX Chart Turbulence Forecast Example8-10
8.2.1.3 Freezing Levels8-10
Figure 8-14. Low-Level SIGWX Chart Freezing Level Forecast Example8-11
Figure 8-15. Low-Level SIGWX Chart Multiple Freezing Levels Example8-11
8.2.2 Issuance8-12
8.2.3 Use8-12
AC 00-45F, CHG 2 Table of Contents Page xii