Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014)
AVIATION
WEATHER
SERVICES
U.S. DEPARTMENT OF COMMERCE
NATIONAL OCEANIC AND ATMOSPHERIC
ADMINISTRATION NATIONAL WEATHER
SERVICE
U.S. DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION Advisory Circular, AC 00-45G, Change 2
Photo courtesy of Aaron A. Gilstad Published October 2014
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014)
SUMMARY OF CHANGES Section Changes
1.1.2.1.1 Changed location of NCEP’s CO from Camp Springs, MD to College Park, MD.
1.1.2.1.2 Added “through the Aviation Digital Data Service (ADDS);” “and “Forecast Icing Product (FIP), Graphical Turbulence Guidance (GTG), and Ceiling and Visibility Product (CVA).”
1.1.2.1.3 Changed name of Hydrometeorological Prediction Center (HPC) to Weather Prediction Center (WPC). Changed location of WPC from Camp Springs, MD to College Park, MD.
1.1.2.1.5 Changed name of Storm Prediction Center (SPC) to National Hurricane Center (NHC)
1.1.2.4 Changed wording from, “WFO Honolulu serves as the Central Pacific Hurricane Center (CPHC)” to “WFO Honolulu is co-located with the Central Pacific Hurricane Center (CPHC).”
1.1.2.5 Deleted.
1.2.1 Changed the location of the Air Traffic Control System Command Center (ATCSCC) from Herndon, VA to Vint Hill, VA.
Changed wording to say “Because weather is the most common reason for air traffic delays and re routings, NWS Meteorologists support the ATCSCC. These meteorologists, called National Aviation Meteorologists (NAMs) orchestrate NWS operations in support of traffic flow management within the NAS.”
1.2.2 Added “… and may solicit PIREPs from pilots.”
1.2.3 Added “… and may solicit PIREPs from pilots.”
1.2.4 Deleted “Automated Flight Service Station (AFSS)”
1.3.1 Changed wording to say “obtained by the pilot from an approved weather source via the Internet (see 1.3.2) and/or from a FSS specialist.”
Changed wording from “helpful” to “necessary.”
Added wording “If the briefing updates previously received information, the time of the last briefing is also important. This allows the briefer to provide only pertinent data.”
Changed wording to say “The briefer enters this information into the FAA’s flight plan system. The briefer also notes the type of weather briefing provided. If necessary, the information can be referenced later to file or amend a flight plan. It is also used when an aircraft is overdue or is reported missing. Internet data is time stamped and archived for 15 days. Voice recordings are retained for 45 days.”
1.3.1.1 Changed and added wording to say “…mountain obscuration, areas of current and forecasted IFR conditions, and other important items such as airport/runway closings, air traffic delays and TFRs.”
1.3.1.1 Added “Prohibited and Special Flight Rules Areas”
1.3.1.3 Deleted “AFSS”
1.3.2 Added “Pilot Briefing via the Internet.”
1.3.2.1 Added “…NWS…” Deleted “To access the weather information and file a flight plan by this method, pilots use a toll free telephone number to connect the user’s computer directly to the DUATS computer.”
1.3.2.2 Added “1.3.2.2 Lockheed Martin Flight Services Web Portal Lockheed Martin Flight Services provides a Web portal for flight planning service at https://www.lmfsweb.afss.com/Website/. Pilots must register and create a user account to access the pilot briefing and flight planning functions. VFR Search and rescue services are Summary of Changes
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014) Section Changes also provided to registered users who file and activate a VFR flight plan and are equipped with certain GPS location devices.”
1.3.3 Text is changed to say “The Aviation Digital Data Service (ADDS) site is a joint effort of NOAA Forecast Systems Laboratory (FSL), NCAR Research Applications Laboratory (RAL), the FAA, and the AWC. ADDS provides the aviation community with textual, digital, and graphical forecasts, analyses, and observations of aviation related weather variables.
Additionally, the ADDS contains a flight path tool that allows the user to view data along a specific route of flight. The user can view icing, turbulence, temperature, winds, humidity, AIRMETs, METARs, TAFs, etc. both horizontally and vertically. This site also allows many overlay options including ARTCC boundaries, counties, highways and rivers. Product animation is also possible on the AWC JavaScript image.”
1.3.4 Deleted “Automated.”
1.3.5 Deleted “AFSS.”
1.3.5 Deleted “AFSS.”
1.3.7.1 Changed wording to say “FIS-B is a ground-based broadcast service provided through the FAA’s ADS-B Services UAT network. The service provides users with a 978 MHz data link capability when operating within range and line-of-sight of a transmitting ground station.
FIS-B enables users of properly equipped aircraft to receive and display a suite of broadcast weather and aeronautical information products.
The following list represents the initial suite of textual and graphical products available through FIS-B and provided free-of-charge. This advisory circular (AC) and the current edition of AC 00 63, Use of Cockpit Displays of Digital Weather and Aeronautical Information, contain detailed information concerning FIS-B meteorological products.
Chapters 3, 4 and 5 of the AIM contain information on Special Use Airspace (SUA), TFR, and NOTAM products.
Text: Aviation Routine Weather Report (METAR) and Special Aviation Report (SPECI);
Text: Pilot Weather Report (PIREP);
Text: Winds and Temperatures Aloft;
Text: Terminal Aerodrome Forecast (TAF) and amendments;
Text: Notice to Airmen (NOTAM) Distant and Flight Data Center;
Text/Graphic: Airmen’s Meteorological Conditions (AIRMET);
Text/Graphic: Significant Meteorological Conditions (SIGMET);
Text/Graphic: Convective SIGMET;
Text/Graphic: Special Use Airspace (SUA);
Text/Graphic: Temporary Flight Restriction (TFR) NOTAM; and Graphic: NEXRAD Composite Reflectivity Products (Regional and National).
Users of FIS-B should familiarize themselves with the operational characteristics and limitations of the system, including: system architecture; service environment; product lifecycles; modes of operation; and indications of system failure.
FIS-B products are updated and transmitted at specific intervals based primarily on product issuance criteria. Update intervals are defined as the rate at which the product data is available from the source for transmission. Transmission intervals are defined as the amount of time within which a new or updated product transmission must be completed and/or the rate or repetition interval at which the product is rebroadcast. Table 1 1 provides update and transmission intervals for each product.
Where applicable, FIS-B products include a look-ahead range expressed in nautical miles (NM) for three service domains: Airport Surface; Terminal Airspace; and En-route/Gulf-of-Mexico (GOMEX). Table 1-1 provides service domain availability and look-ahead ranging for each FIS-B product.
Prior to using this capability, users should familiarize themselves with the operation of FIS -B avionics by referencing the applicable User’s Guides. Users should obtain guidance Summary of Changes
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014) Section Changes concerning the interpretation of information displayed from the appropriate avionics manufacturer.
Users should report FIS-B malfunctions not attributed to aircraft system failures or covered by active NOTAM to the nearest FSS facility by radio or telephone. Users may also report malfunctions by submitting FAA Form 8740 5, Safety Improvement Report, via mail, fax, or email to your local Flight District Standards Office (FSDO) Safety Program Manager.
Added Table 1-1. FIS-B Over UAT Product Update and Transmission Intervals, and Table 1-2, Product Parameters for Low/Medium/High Altitude Tier Radios.
1.3.7.2 Deleted second and third subparagraphs.
2 Changed title to say “Aviation Weather Product Policy” 2 Changed first bullet to say “policy guidance for using aviation weather products,”
2.1 Removed content regarding primary and supplemental classification. Deleted subparagraphs 2.1.1 and 2.1.2.
2.3.1 Second subparagraph Added wording “…Lockheed Martin, Direct Use Access Terminal Service (DUAT/DUATS )”
2.3.2 and
2.3.3 Paragraph order was swapped.
2.3.2 Last two sentences deleted.
2.3.3 First paragraph Content changed to say “An EWINS is a system for gathering, evaluating, and disseminating aviation weather information, and for issuing weather reports and forecasts prepared by properly trained and qualified aviation meteorologists or aircraft dispatchers. Air carriers use EWINS, which are proprietary to each carrier. In order to use an EWINS, each air carrier requires FAA approval.
2.3.3 Second paragraph First sentence changed to say “…each carrier’s EWINS…” FSIMS section corrected to Section 4 Text changed to include part 91K operators.
Last sentence changed to say “These approved operators may conduct flight operations using the weather analyses and forecasts produced by their approved EWINS.”
Section 9 Title changed to “New Generation Weather Products”
9.1 Text changed to say “…4-, 6 -, and 8-hours…”
9.1.3.2 Changed reference to Figure 9-3 to Figure 9-2. Deleted Figure 9-3. Renumbered figures, updated figure references.
9.1.3.4.3 Changed text to read “Confidence depicted on the chart…”
9.1.3.4.4 Changed text to read “Coverage is used to depict the forecast…”
9.1.5 First subparagraph Text changed to say “The CCFP is a strategic planning tool for air traffic flow management in the 4- to 8-hour forecast period.
9.1.5 Second subparagraph Text added “…l; however CCFP is available to pilots and aircraft dispatchers as an additional tool for strategic planning.”
9.2 Extended Convective Forecast Product (ECFP) New section The ECFP Planning Tool (Figure 9-2) is a graphical representation of the forecast probability of thunderstorms. The product identifies graphically where in the United States thunderstorms are likely over the next 72 hours. It is intended to enhance the CCFP. The CCFP is only valid out to 8 hours. This graphical product will use CCFP-style graphics, to Summary of Changes
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014) Section Changes facilitate ease of interpretation and use by those already familiar with the CCFP. The product is not a CCFP forecast (it is not forecasting the exact CCFP criteria), but intended to support the long range planning for CCFP type of constraints in the National Airspace System (NAS).
9.2.1 Issuance The development of the ECFP planning tool was a response to Federal Aviation Administration (FAA) and Industry needs in planning for weather hazards, specifically convection, one to two days in advance. To meet these planning needs, and to support CCFP planning beyond 8 hours, the ECFP intends to provide traffic planners and collaborators a quick-look forecast of the greatest probability of convection/thunderstorms.
By utilizing CCFP-style graphics, users familiar with CCFP can easily determine where traffic constraints are most likely to occur over the next 3 days.
9.2.1 Figure 9-6, ECFP Example added.
9.2.2 Content This automated graphical forecast is created from the Short Range Ensemble Forecast (SREF) Calibrated Thunderstorm guidance. Probability of Thunderstorm contours are depicted at 40, 60, and 80 percent probabilities, using CCFP-like shading. Hashed areas represent 40 59 percent probability, solid lined areas represent 60–79 percent probability, and solid blue filled areas represent greater than 80 percent probability.
9.2.3 Use The ECFP is intended for FAA Traffic Managers at Air Route Traffic Control Centers (ARTCC), FAA Air Traffic Control System Command Center (ATCSCC), airline and aviation industry dispatch and flight planners, and commercial weather information providers supporting airline/FAA.
9.2.3 Deleted “The ADDS and AWC JAVA display” entire paragraph
9.2.4 Frequency The ECFP is available 24/7 with updates issued at 01:00, 07:00, 13:00, and 19:00 UTC each day.
9.3 All paragraph numbers updated due to added section 9.2.
9.3 Changed wording to say “…may be used in conjunction to…” Changed last line from “airline” to “aircraft”
9.3.3.1 Added subparagraph Strengths.
9.3.3.2 Added subparagraph Limitations.
9.3.4 Deleted “The NCWF is a supplement to, but does not substitute for, the report and forecast information contained in Convective SIGMETs.”
9.4 Renumbered paragraphs due to added information.
9.4 Changed title to read “Current and Forecast Icing Products (CIP/FIP)”
9.4 First subparagraph Added “The Forecast Icing Product (FIP) provides the same suite of products describing the icing environment in the future and is solely NWP model-based.”
9.4 Second subparagraph Added “The CIP/FIP product suites are automatically produced with no human modifications. Information on the graphics is determined from NWP model output, observational data including WSR-88D radar, satellite, pilot weather reports, surface weather reports, and lightning network data.”
9.4.1 Changed wording to say “The CIP and FIP product suites are issued hourly ~15 minutes after the hour by the Aviation Weather Center (AWC). The products are available through the Aviation Digital Data Service (ADDS) web site at:
http://www.aviationweather.gov/adds/icing/” Summary of Changes
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014) Section Changes
9.4.2 Added “…/FIP …”
9.4.2 Changed to say “The CIP/FIP products are generated for individual altitudes from 1,000 feet MSL to Flight Level (FL) 300 at intervals of 1,000 feet. Horizontal resolution is 20 km. FIP products are available at 1, 2, 3, 6, 9, and 12- h forecast lead times. By March 2014 these are planned to change to 500 ft. MSL horizontal and 13 km vertical resolution, and forecasts will be extended to 18 h with 1-h granularity.”
9.4.2 Last subparagraph Added “…FIP…”
9.4.4 First subparagraph Changed wording to say “The CIP/FIP Icing Probability product can be used to identify the current and forecast three-dimensional probability of icing. The CIP/FIP should be used in conjunction with the report and forecast information contained in an AIRMET and SIGMET.
9.5 Changed wording to say” The Graphical Turbulence Guidance (GTG) product suite provides a three-dimensional diagnosis and forecast of Clear Air Turbulence (CAT) potential. The GTG is created using a combination of computer model output and turbulence observations.
The GTG product suite, which consists of the GTG analysis and forecast and Composite analysis and forecast, is automatically generated with no human modifications. It should be used in conjunction with the report and forecast information contained in an AIRMET and SIGMET. The GTG is available for the 48-contiguous states, much of Canada and Mexico and their respective coastal waters.
9.5.1 Changed wording to say “Issuance The GTG analysis is issued hourly. The 3-, 6-, 9-, and 12-hour forecasts are issued every three hours beginning at 00Z. For example, a forecast suite issued at 0600Z would have valid times at 0900Z, 1200Z, 1500Z, and 1800Z respectively. The GTG Analysis and Forecasts, along with the Composite products, are issued by the Aviation Weather Center (AWC) and are available through the Aviation Digital Data Service (ADDS) web site at:
http://adds.aviationweather.noaa.gov/turbulence/turb_nav.php.
9.5.2.1 Changed wording to say “The GTG output is available for 1,000 foot vertical intervals between 10,000 feet MSL and FL450. ADDS turbulence page displays every second level starting at 10,000 feet MSL level, while the ADDS Flight Path Tool provides access to all levels.
9.5.2.2 Changed wording to say “GTG Composite Analysis and Forecast The GTG Composite products display the maximum intensity of potential turbulence between FL200 and FL450 (Figure 9-23).
Deleted Figure 9-23, GTG Example. Renumbered Figure 9-24. GTG Composite Example to Figure 9-23
9.5.3 Changed wording to say “The GTG provides an hourly, high resolution analysis and forecast of clear-air turbulence potential at and above10,000 feet MSL. However, the product is only for turbulence associated with upper level fronts and jet stream while other known causes of turbulence are not forecasted.
Strengths
1. The product is issued hourly
2. Turbulence is plotted to a high resolution.
Limitations
1. The accuracy of the analysis is dependent on the number of PIREPs available.
Typically at night fewer pilot reports are received, so the accuracy decreases.
2. For the GTG forecast, the product is only as accurate the computer model output used to create them.
3. The product only displays clear-air turbulence (CAT) for upper-level fronts and the jet stream. Other known causes of turbulence are not included in the product.
Summary of Changes
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014) Section Changes
4. Data and forecast are only available for 11,000 feet MSL and above.”
9.5.3.1 Changed wording to say “Strengths
• The product is issued hourly
• Turbulence is plotted to a high resolution.”
9.5.3.2 Changed wording to say “Limitations
• The accuracy of the analysis is dependent on the number of PIREPs available.
Typically at night fewer pilot reports are received, so the accuracy decreases.
• For the GTG forecast, the product is only as accurate the computer model output used to create them.
• The product only displays clear-air turbulence (CAT) for upper-level fronts and the jet stream. Other known causes of turbulence are not included in the product.
• Data and forecast are only available for 11,000 feet MSL and above.”
9.6 Renumbered Figure 9-25 to Figure 9-24; Figure 9-26 to Figure 9-25; and Figure 9-27 to Figure 9-26.
9.7 New section added, “9.7 Ceiling and Visibility Analysis (CVA)” Summary of Changes
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014)
FOREWORD Aviation Weather Services, Advisory Circular 00-45G, is published jointly by the National Weather Service (NWS) and the Federal Aviation Administration (FAA). This publication supplements its companion manual Aviation Weather, Advisory Circular 00-6A, which documents weather theory and its application to the aviation community.
This advisory circular, AC 00-45G, explains U.S. aviation weather products and services. It details the interpretation and application of advisories, coded weather reports, forecasts, observed and prognostic weather charts, and radar and satellite imagery. Product examples and explanations are taken primarily from the Aviation Weather Center’s Aviation Digital Data Service website (http://adds.aviationweather.noaa.gov/).
An online version of this document (including digital images) can be found at http://rgl.faa.gov/ Aviation Weather Services, Advisory Circular, AC 00-45G Change 2, supersedes AC 00-45G, Change 1, published July 29, 2010.
Deputy Director, Flight Standards Service Foreword
Aviation Weather Services, Advisory Circular 00-45G Change 2 (October 2014)
1 AVIATION WEATHER SERVICE PROGRAM1-1
1.1 N ATIONAL 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
NCEP Central Operations (NCO)1-2
Aviation Weather Center (AWC)1-2
Weather Prediction Center (WPC)1-2
Storm Prediction Center (SPC)1-2
National Hurricane Center (NHC)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
1.2 F EDERAL 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)1-5
1.3 D ISSEMINATION 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 Pilot Briefing via the Internet1-8
1.3.2.1 Direct Use Access Terminal Service (DUATS/DUAT)1-8
1.3.2.2 Lockheed Martin Flight Services Web Portal1-8
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)1-10
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
Table 1-1. FIS-B Over UAT Product Update and Transmission Intervals1-13
Table 1-2. Product Parameters for Low/Medium/High Altitude Tier Radios1-14
1.3.7.2 Operational Use of FIS-B Products1-15
2 AVIATION WEATHER PRODUCT POLICY2-1
2.1 USE OF AVIATION WEATHER PRODUCTS2-1
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 SOURCES2-3
2.3.1 Federal Government2-3
2.3.2 Enhanced Weather Information System (EWINS)2-3
2.3.3 Commercial Weather Information Providers2-4
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
3.1.3 Format3-3
Table of Contents ii
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
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)3-6
3.1.3.5 Wind Group3-6
Wind Gust3-6
Variable Wind Direction (speed 6 knots or less)3-7
Variable Wind Direction (speed greater than 6 knots)3-7
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 Weather3-9
Intensity Qualifier3-10
Proximity Qualifier3-10
Descriptor Qualifier3-10
Precipitation3-11
Obscuration3-11
Other Weather Phenomena3-11
3.1.3.9 Sky Condition Group3-12
Figure 3-3. Obscuration Effects on Slant Range Visibility3-13
Table 3-3. METAR/SPECI Contractions for Sky Cover3-14
Table 3-4. METAR/SPECI Increments of Reportable Values of Sky Cover Height3-14
Figure 3-4. METAR/SPECI Sky Condition Coding3-15
3.1.3.10 Temperature/Dew Point Group3-16
3.1.3.11 Altimeter ........................................................................................................................................................ 3- 16
3.1.3.12 Remarks (RMK)3-16
Table 3-5. METAR/SPECI Order of Remarks3-17
3.1.3.13 Automated, Manual, and Plain Language Remarks3-18
Volcanic Eruptions (Plain Language)3-18
Funnel Cloud3-19
Type of Automated Station3-19
Peak Wind3-19
Wind Shift3-19
Tower or Surface Visibility3-19
Variable Prevailing Visibility3-19
Sector Visibility (Plain Language)3-19
Visibility at Second Location3-19
Lightning3-20
Table 3-6. ME TAR/SPECI Type and Frequency of Lightning3-20
Beginning and Ending of Precipitation3-20
Beginning and Ending of Thunderstorms3-21
Thunderstorm Location (Plain Language)3-21
Hailstone Size (Plain Language)3-21
Virga (Plain Language)3-21
Variable Ceiling Height3-22
Obscurations (Plain Language)3-22
Variable Sky Condition (Plain Language)3-22
Significant Cloud Types (Plain Language)3-22
Cumulonimbus or Cumulonimbus Mammatus3-22
Figure 3-5. Cu mulonimbus (CB) Example3-23
Figure 3-6. Cumulonimbus Mammatus (CBMAM) Example3-23
Towering Cumulus3-24
Figure 3-7. To wering Cumulus (TCU) Example3-24
Altocumulus Castellanus3-25
Figure 3-8. Alt ocumulus Castellanus (ACC) Example3-25
Standing Lenticular or Rotor Clouds3-26
Figure 3-9. St anding Lenticular and Rotor Clouds Example3-26
Ceiling Height at Second Location3-26
Pressure Rising or Falling Rapidly3-27
Table of Contents iii
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
Sea-Level Pressure3-27
Aircraft Mishap (Plain Language)3-27
No SPECI Reports Taken (Plain Language)3-27
Snow Increasing Rapidly3-27
Other Significant Information (Plain Language)3-27
3.1.3.14 A dditive and Automated Maintenance Data ................................................................................................... 3- 27
Hourly Temperature and Dew Point3-27
Maintenance Data Groups3-28
Sensor Status Indicators3-28
Maintenance Indicator3-28
3.1.4 METAR/SPECI Examples3-29
3.2 PILOT WEATHER REPORTS (PIREP)3-34
3.2.1 Format3-34
Figure 3-10. Pilot Weather Report (PIREP) Coding Format3-34
3.2.1.1 Message Type (UUA/UA)3-34
Urgent PIREPs3-34
Routine PIREPs3-35
3.2.1.2 Location (/OV) ............................................................................................................................................... 3- 35
Location3-36
Route Segment3-36
3.2.1.3 Time (/TM)3-36
3.2.1.4 Altitude/Flight Level (/FL)3-36
3.2.1.5 Aircraft Type (/TP)3-36
3.2.1.6 Sky Condition (/SK)3-37
3.2.1.7 Flight Visibility and Weather (/WX)3-38
Table 3-7. PIREP Weather Type and Symbols3-39
3.2.1.8 Air Temperature (/TA) ................................................................................................................................... 3- 41
3.2.1.9 Wind Direction and Speed (/WV) ................................................................................................................... 3- 41
3.2.1.10 Turbulence (/TB) ............................................................................................................................................ 3- 41 Table 3-8. PIREP Turbulence Reporting Criteria.............................................................................. 3- 42
3.2.1.11 Icing (/IC) ....................................................................................................................................................... 3- 42
Table 3-9. Icing Intensities, Contractions, and Airframe Ice Accumulation3-44
Table 3-10. Icing Types, Contractions, and Descriptions3-44
3.2.1.12 Remarks (/RM)3-44
Wind Shear3-45
FUNNEL CLOUD, TORNADO, and WATERSPOUT3-45
Thunderstorm3-45
Lightning3-45
Electrical Discharge3-45
Clouds3-46
Plain Language3-46
Volcanic Eruptions3-46
SKYSPOTTER3-46
3.2.2 PIREP Examples3-47
3.3 RADAR WEATHER REPORT (SD/ROB)3-49
Figure 3-11. Radar Weather Report (SD/ROB) Coding Format3-49
3.3.1 Format3-49
3.3.1.1 Location Identifier .......................................................................................................................................... 3- 49
3.3.1.2 Time ............................................................................................................................................................... 3- 49
3.3.1.3 Configuration3-49
Figure 3-12. Radar Weather Report (SD/ROB) Configurations3-51
3.3.1.4 Coverage ........................................................................................................................................................ 3- 51
3.3.1.5 Precipitation Type .......................................................................................................................................... 3- 51
3.3.1.6 Precipitation Intensity ..................................................................................................................................... 3- 52 Table 3-11. SD/ROB Reportable Intensities ........................................................................................ 3- 52
3.3.1.7 Location ......................................................................................................................................................... 3- 52
Figure 3-13. SD/ROB AREA, Line (LN), and CELL Location Examples3-53
3.3.1.8 Maximum Top ................................................................................................................................................ 3- 53
3.3.1.9 Cell Movement ............................................................................................................................................... 3- 53
3.3.1.10 Remarks ......................................................................................................................................................... 3- 54
Table 3-12. Weather Radar Report Remarks and Meaning3-54
Table of Contents iv
Aviation Weather Services, Advisory Circular 00-45G Change 1 (July 2010)
3.3.1.11 Digital Section ................................................................................................................................................ 3- 54
Figure 3-14. SD/ROB Digital Section Information Plotted on a PPI Grid Overlay Example3-55
3.3.2 Examples3-55
Figure 3-15. WSR-88D Weather Radar Network Sites3-57
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 Example4-3
Figure 4-3. WSR-88D Weather Radar Long Range (248 NM)
Base Reflectivity Product Example4-4
Base Reflectivity Use4-4
Figure 4-4. WSR-88D Weather Radar Stratiform Precipitation on the 5º Base Reflectivity
Product Example4-5
Figure 4-5. WSR-88D Weather Radar Convective Precipitation on the 5º Base Reflectivity
Product Example4-5
Strengths of Base Reflectivity4-6
Limitations of Base Reflectivity4-6
Radar Beam Overshooting4-6
Beam Blockage4-6
Figure 4-6. WSR-88D Weather Radar Beam Blockage on Base Reflectivity Product Example4-7
Ground Clutter4-7
Figure 4-8. WSR-88D Weather Radar Ground Clutter Example4-7
Ghost4-8
Figure 4-9. WSR-88D Weather Radar Ghost Example4-8
Angels4-8
Figure 4-10. WSR-88D Weather Radar Angle Example4-9
Anomalous Propagation (AP)4-9
Figure 4-11. WSR-88D Weather Radar Anomalous Propagation (AP) Example4-10
4.1.4.2 Composite Reflectivity ................................................................................................................................... 4- 10 Figure 4-12. Creation of a Composite Reflectivity Product ............................................................... 4- 10 Figure 4-13. WSR-88D Weather Radar Short Range (124 NM) Composite Reflectivity Product Example ............................................................................................................. 4- 11
Composite Reflectivity Use4-11
Figure 4-14. WSR-88D Weather Radar 5º Base Reflectivity versus Composite Reflectivity Comparison ..................................................................................................................... 4- 12
Strengths of Composite Reflectivity4-12
Limitations of Composite Reflectivity4-12
Radar Beam Overshooting4-12
Beam Blockage4-12
Ground Clutter4-13
Ghost4-13
Angels4-13
Anomalous Propagation (AP)4-13
4.1.5 Radar Mosaics4-13
4.1.5.1 0.5º Mosaics – Contiguous U.S. and Hawaii ................................................................................................... 4- 14 Table 4-2. NWS Radar Mosaic Products ............................................................................................ 4- 14
Figure 4-15. Great Lakes Regional Radar Mosaic Example4-14
4.1.5.2 0.5º Mosaics – Alaska ..................................................................................................................................... 4- 15 Figure 4-16. Alaskan Regional Radar Mosaic Example ..................................................................... 4- 15
4.2 SATELLITE4-16
4.2.1 Description4-16
Table of Contents v