Aviation Weather Services, Advisory Circular 00-45F, Revision 1 By FAA policy CIP is a Supplementary Weather Product for enhanced situational awareness only and must be used with one or more primary products (safety decision) such as an AIRMET or SIGMET (see AIM 7—1-3).
Maximum icing severity (prob>25%) (1000 ft. MSL to FL300) Analysis valid 1700 UTC Mon 27 Nov 2006 None <25% Trace Light Moderate Heavy
4) Trace-Light WiLight-Moderate 1) Moderate-Savare Icing PIREP Symbols W Traca Ll Light ' Moderate Yul Severa Figure 9-17. CIP Icing Severity Probability >25% Example The lightest blue color represents trace icing. As the blue color shades become darker, the icing intensity increases. The darkest blue color represents heavy icing. White regions indicate where no probability of icing exists and, therefore, no intensity is necessary. A gray color is used to mask the intensity pixels where the probability of icing is 25% or less.
9.3.2.7 Icing Severity - Probability > 50% The Icing Severity - Probability > 50% product (Figure 9-18) depicts, at a single altitude, where the probability of the indicated icing intensity 51 to 100 percent. Icing intensity is displayed using standard icing intensity categories: trace, light, moderate and heavy.
AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-19
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 By FAA policy CIP is a Supplementary Weather Product for enhanced situational awareness only and must be used with one or more primary products (safety decision) such as an AIRMET or SIGMET (see AIM 7-1-3).
Icing severity (prob>50%) at 3000 ft. MSL Analysis valid 1500 UTC Mon 27 Nov 2006 terrain None <50% Trace Light Moderate Heavy ga Negative LJ Trace-Light W Light-Moderate | Moderate-Severe Icing PIREP Symbals W Trace Le Light HI Madsrate If Savara Figure 9-18. CIP Icing Severity Probability > 50% Example The lightest blue color represents trace icing. As the blue color shades become darker, the icing intensity increases. The darkest blue color represents heavy icing. White regions indicate where no probability of icing exists and, therefore, no intensity is necessary. Brown regions indicate where higher-elevation terrain extends above the altitude of the particular graphic. A gray color is used to mask the intensity pixels where the probability of icing is 50% or less.
9.3.2.8 Icing Severity - Probability > 50% - Maximum The Icing Severity - Probability > 50% - Maximum product (Figure 9-19) depicts, at all altitudes from 1,000 feet MSL to FL300, where the probability of the indicated icing intensity is 51 to 100 percent. Icing intensity is displayed using standard icing intensity categories: trace, light, moderate and heavy.
AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-20
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 By FAA policy CIP is a Supplementary Meather Product for enhanced situational awareness only and must be used with one or more primary products (safety decision) such as an AIRMET or SIGMET (see AIM 7-1-3).
Maximum icing severity (prob>50%) (1000 fl. MSL to FL300) Analysis valid 1700 UTC Mon 27 Nov 2006 None <50% Trace Light Moderate Heavy Wi Trace-Light N Light-Moderate I Moderate-Savara leing PIREP Symbols W Trace Yu Light 4) Moderate I Severa Figure 9-19. CIP Icing Severity Probability > 50% - Max Example The lightest blue color represents trace icing. As the blue color shades become darker, the icing intensity increases. The darkest blue color represents heavy icing. White regions indicate where no probability of icing exists and, therefore, no intensity is necessary. A gray color is used to mask the intensity pixels where the probability of icing is 50% or less.
9.3.2.9 Icing Severity plus Supercooled Large Droplets (SLD) The Icing Severity plus Supercooled Large Droplets (SLD) product (Figure 9-20) depicts, at a single altitude, the intensity of icing expected as well as locations where a threat for SLD exists.
SLD is defined as supercooled water droplets larger than 50 micrometers in diameter. These size droplets include freezing drizzle and/or freezing rain aloft. SLD, which are outside the icing AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-21
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 certification envelopes (FAR Part 25 Appendix C), can be particularly hazardous to some aircraft.
Icing intensity is displayed using standard icing intensity categories: trace, light, moderate and heavy.
ly FAR policy LIP is a Supplementary neather Product tor enhanced situational avareness only and must bi ised with one or more primary products (safety decision) such as an AIRMET or SIGMET (see AM 7-1-3) Icing severity at 3000 ft. MSL Analysis valid 1800 UTC Mon 27 Nov 2006 SLD threat terrain None Trace Light Moderate Heavy ø Negative LJ Trace-Light / Light-Moderate I Maderate-Savare cing PIREP Symbals W Trace Let Light If Moderate Kyl severe Figure 9-20. CIP Icing Severity plus Supercooled Large Droplets (SLD) Example The lightest blue color represents trace icing. As the blue color shades become darker, the icing intensity increases. The darkest blue color represents heavy icing. White regions indicate where no probability of icing exists and, therefore, no intensity is necessary. Brown regions indicate where higher-elevation terrain extends above the altitude of the particular graphic.
Locations where a threat for SLD exists are depicted with red hatching.
AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-22
Aviation Weather Services, Advisory Circular 00-45F, Revision 1
9.3.2.10 Icing Severity plus Supercooled Large Droplets (SLD) - Maximum The Icing Severity plus Supercooled Large Droplets (SLD) product (Figure 9-21) depicts at all altitudes, between 1,000 feet MSL and FL300, the intensity of icing expected as well as locations where a threat for SLD exists.
SLD is defined as supercooled water droplets larger than 50 micrometers in diameter. These size droplets include freezing drizzle and/or freezing rain aloft. SLD, which are outside the icing certification envelopes (FAR Part 25 Appendix C), can be particularly hazardous to some aircraft.
By FAA policy CIP is a Supplementary Weather Product for enhanced situational awareness only and must be used mith one or more primary products (safety decision) such as an AIRMET or SIGMET (see AIM 7—1—3).
Maximum icing severity (1000 ft. MSL to FL300) Analysis valid 1500 UTC Mon 27 Nov 2006 SLD threat None Trace Light Moderate Heavy I Trace-Light W Light-Moderate I Moderate-Savare cing PIREP Symbols W Trace Ly Light * Moderate yul Severe Figure 9-21. CIP Icing Severity plus Supercooled Large Droplets (SLD) - Max Example The lightest blue color represents trace icing. As the blue color shades become darker, the icing intensity increases. The darkest blue color represents heavy icing. White regions indicate AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-23
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-24 where no probability of icing exists and, therefore, no intensity is necessary. Locations where a threat for SLD exists are depicted with red hatching.
9.3.3 Strengths and Limitations
9.3.3.1 Strengths The CIP product suite is updated hourly and provides a diagnostic tool to assist in determining the probability for icing, the intensity of icing and the threat for SLD.
9.3.3.2 Limitations Actual icing severity may be different than what is depicted on the CIP graphics and plotted PIREPS because:
Different aircraft types experience different severities of icing in the same atmospheric environments. Severity definitions are currently pilot-based and thus are a function of the aircraft type, flight phase (takeoff/landing, cruise, etc.), aircraft configuration, as well as the pilot’s experience and perception of the icing hazard.
Assessing the amount and drop size of supercooled liquid water (SLW) in the atmosphere is difficult.
The Icing Severity products depict the severity of the meteorological icing environment and not the resultant icing that may occur on the aircraft.
9.3.4 Uses The CIP Icing Probability product can be used to identify the current three-dimensional probability of icing.
The CIP Icing Severity product can be used to determine the intensity of icing. The CIP Icing Severity – Probability > 25% or Probability > 50% depicts the probability of a given intensity of icing occurring.
Finally the Icing Severity plus SLD product can help in determining the threat of SLD which is particularly hazardous to some aircraft.
Icing PIREPs are plotted on single altitude graphics if the PIREP is within 1,000 feet of the graphic’s altitude and has been observed within 75 minutes of the chart’s valid time. On CIP Max product, PIREPs for all altitudes (i.e. 1,000 feet MSL to FL300) are displayed. However, negative reports of icing are not plotted on the CIP Max product in an effort to reduce clutter.
The PIREP legend is located on the bottom of each graphic.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-25
9.4 Forecast Icing Potential (FIP) The Forecast Icing Potential (FIP) provides a three-dimensional forecast of icing potential (or likelihood) using numerical weather prediction model output (Figure 9-17). The FIP product suite is automatically generated with no human modifications. It may be used as a higher resolution supplement to AIRMETs and SIGMETs but is not a substitute for them. It is authorized for operational use only by meteorologists and dispatchers. The forecast area covers the 48-contiguous states, much of Canada and Mexico and their respective coastal waters.
9.4.1 Issuance The FIP is issued every hour and generates hourly forecast for 3 hours into the future. For example, forecasts issued at 1300Z would be valid for 1400Z, 1500Z and 1600Z. Six-, 9-, and 12-hour forecasts are issued every three hours beginning at 00Z. For example, a forecast suite issued at 0300Z would have valid times at 0900Z, 1200Z and 1500Z respectively. The product is issued by the Aviation Weather Center (AWC) and is available through the Aviation Digital Data Service (ADDS) web site at: http://adds.aviationweather.noaa.gov/icing/icing_nav.php.
9.4.2 Content The FIP forecasts the likelihood of icing from super-cooled liquid water droplets. The likelihood field ranges from 0 (no icing) to 100 (icing likely). The scale depicts likelihood of icing using “cool” and “warm” colors, with warmer colors indicating a higher likelihood of icing. Regions depicted in white indicate zero icing potential according to the CIP. Brown regions indicate areas of terrain.
The scale is not calibrated as a true probability value. It does, however, have value in pointing out differences in the likelihood of encountering icing at a given location. For example, a value of 70 does not indicate there is a 70 percent chance of encountering icing. However, when comparing it to other higher or lower values will indicate if there is a greater or lesser likelihood of encountering icing. No information is provided as to the severity of icing and none should be inferred. FIP output is available for 1,000 foot vertical intervals. ADDS displays every third level except on the Flight Path Tool which provides access to all levels.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-26
Figure 9-22. FIP Example
9.4.3 Strengths and Limitations
Strengths
The FIP can be used to help determine the forecast for potential for icing through the entire vertical depth of the atmosphere.
The product is updated hourly.
Limitations
The product does not display any information about the severity of icing.
The product only displays the forecast potential for icing, not the absolute probability.
It is only approved for use by meteorologists and dispatchers.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-27
The product is generated without human modification. Therefore, the forecasts are only as accurate the computer model output used to create them.
9.4.4 Use The FIP is primarily used to help determine the likelihood of icing at the specified forecast valid times.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-28
9.5 Graphical Turbulence Guidance (GTG) 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 may be used as a supplement to AIRMETs and SIGMETs but is not a substitute for them. It is authorized for operational use only by meteorologist and dispatchers. The GTG is available for the 48-contiguous states, much of Canada and Mexico and their respective coastal waters.
9.5.1 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 Content
9.5.2.1 GTG Analysis and Forecast The GTG Analysis and Forecast graphics depict the location and intensity of potential Clear Air Turbulence (CAT) (Figure 9-18). Standard intensity terminology is used. The GTG output is available for 1,000 foot vertical intervals between FL200 and FL450. ADDS turbulence page displays every third level starting at FL210 level, while the ADDS Flight Path Tool provides access to all levels.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-29
Figure 9-23. GTG Example
9.5.2.2 GTG Composite Analysis and Forecast The GTG Composite products display the maximum intensity of potential turbulence between FL200 and FL450 (Figure 9-19). In other words, at any given location, the displayed value represents the maximum potential turbulence between FL200 and FL450. Single altitude graphics must be examined to determine the altitude of the potential turbulence.
Aviation Weather Services, Advisory Circular 00-45F, Revision 1 AC 00-45F (July 2008) Section 9: Supplementary Products Page 9-30
Figure 9-24. GTG Composite Example
9.5.3 Strengths and Limitations The GTG provides an hourly, high resolution analysis and forecast of clear-air turbulence potential at and above FL200. However, the product is only for turbulence associated with upper level fronts and jet streams while other known causes of turbulence are not forecasted.
Strengths
The product is issued hourly
Turbulence is plotted to a high resolution.
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.