Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
9.3.2.4 Icing Severity -- Maximum The Icing Severity - Maximum product (Figure 9-15) displays the intensity of icing at all altitudes from 1,000 feet MSL to FL300. Icing intensity is displayed using standard icing intensity categories: trace, light, moderate and heavy.
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 (1000 ft. MSL to FL300) Analysis valid 1600 UTC Mon 27 Nov 2006 None Trace Light Moderate Heavy 1]) Trace-Light V Light-Moderate \I Moderate-Savara Icing PIREP Symbols & Trace LylLight W/ Moderate 'y! Savare Figure 9-15. CIP Icing Severity - 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.
9.3.2.5 Icing Severity - Probability > 25% The Icing Severity - Probability > 25% product (Figure 9-16) depicts, at a single altitude, where a 26 to 100 percent probability exists for the indicated icing intensity. Icing intensity is displayed using standard icing intensity categories: trace, light, moderate and heavy.
AC 00-45F, CHG 2 Section 9: Supplementary Products Page 9-17
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009) dy FAA policy CIP is a Supplementary Weather Product for enhanced situational awareness only and must ba ised with one or more primary products (safety decision) such as an AIRMET or SIGMET (see AIM 7—1—3).
Icing severity (prob>25%) at 3000 ft. MSL Analysis valid 1500 UTC Mon 27 Nov 2006 terrain None <25% Trace Light Moderate Heary ø3 Negative Ц/ Trace-Light Vp Light-Moderate L Moderate-Savara Icing PIREP Symbols W Trace Lylight 4) Moderate Ly Savare Figure 9-16. 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. Brown regions indicate higher-elevation terrain extending above the altitude of the particular graphic. A gray color is used to mask the intensity pixels where the probability of icing is 25% or less.
9.3.2.6 Icing Severity - Probability > 25% - Maximum The Icing Severity - Probability > 25% - Maximum product (Figure 9-17) depicts, at all altitudes from 1,000 feet MSL to FL300, where the probability of the indicated icing intensity is 26 to 100 percent. Icing intensity is displayed using standard icing intensity categories: trace, light, moderate, heavy.
AC 00-45F, CHG 2 Section 9: Supplementary Products Page 9-18
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009) 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 Vy Light-Moderate 1 Moderate-Savera Icing PIREP Symbols W Trace L) Light / Moderate Yu/ Severe 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, CHG 2 Section 9: Supplementary Products Page 9-19
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009) By FAA policy CIP is a Supplementary Weather Product for enhanced situational awareness only nd 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 ø Negative 4J Trace-Light Vp Light-Moderate I Moderate-Severe Icing PIREP Symbols W Trace Le Light / Moderate If Savare 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, CHG 2 Section 9: Supplementary Products Page 9-20
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009) 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 AM 7-1-3j.
Maximum icing severity (prob>50%) (1000 fl. MSL to FL300) Analysis valid 1700 UTC Mon 27 Nov 2006 None <50% Trace Light Moderate HedYy
4) Trace-Light WU Light-Maderate _ Moderate-Savere Icing PIREP Symbals W Trace Ll Light Wu Moderate Ip! Savers 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, CHG 2 Section 9: Supplementary Products Page 9-21
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009) 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.
By FAA policy CIP is a Supplementary Weather Product for enhanced situational avareness only and must be used mith 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 ø3 Negative WJ Trace-Light Vp Light-Moderate I Moderate-Savera cing PIREP Symbols I Trace Kul Light Y/ savere 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, CHG 2 Section 9: Supplementary Products Page 9-22
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
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 bea used with 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 If Trace-Light I Light-Moderate I Moderate-Severe Icing PIREP Symbale W Trace Yul Light y Moderate fl 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, CHG 2 Section 9: Supplementary Products Page 9-23
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009) 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 seve rity 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.
AC 00-45F, CHG 2 Section 9: Supplementary Products Page 9-24
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
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.
AC 00-45F, CHG 2 Section 9: Supplementary Products Page 9-25
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
Figure 9-22. FIP Example
9.4.3 Strengths and Limitations
Strengths
y The FIP can be used to help determine the forecast for potential for icing through the entire vertical depth of the atmosphere.
y The product is updated hourly.
Limitations
y The product does not display any information about the severity of icing.
y The product only displays the forecast potential for icing, not the absolute probability.
y It is only approved for use by meteorologists and dispatchers.
AC 00-45F, CHG 2 Section 9: Supplementary Products Page 9-26
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
y 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.
AC 00-45F, CHG 2 Section 9: Supplementary Products Page 9-27
Aviation Weather Services, Advisory Circular 00-45F, Change 2 (March 2009)
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.
AC 00-45F, CHG 2 Section 9: Supplementary Products Page 9-28