Figure 5-77. CIP/FIP Icing Probability (3,000 Feet MSL)-Example Probability of icing at 3000 ft. MSL Analysis valid 1500 UTC Mon 27 Nov 2006 terrain 15 25 35 45 55 65 75 es Negative Y/ Trace-Light W| Light-Moderate W Moderate-Severa (percent) cing PIREP Symbols W Trace Lyl Light / Moderate Y! Severa "Cool" colors (e.g., blue and green) represent low probabilities and "warm" colors (orange and red) represent higher probabilities. Probabilities do not reach 100 percent because the data used to determine the probability of icing cannot diagnose, with absolute certainty, the presence of icing conditions at any location and altitude. White regions indicate where no probability of icing exists. Brown regions indicate where higher-elevation terrain extends above the altitude of the particular graphic.
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5-149 Figure 5-78. CIP/FIP Icing Probability—Max Example
5.21.1.2.2 Icing Severity.
The Icing Severity product depicts the icing intensity likelihood at locations where the icing probability product depicts possible icing. Icing intensity is displayed using icing intensity categories: trace, light, moderate, and heavy.
The product is available on https://www.aviationweather.gov in single altitudes, e.g., 3,000 ft MSL (se e Figure 5-79, CIP/FIP Icing Severity (3,000 Feet MSL)—Example), or a composite of all altitudes from 1,000 ft MSL to FL300, i.e., max level (see Figure 5-80, CIP/FIP Icing Severity—Max Example).
Figure 5-79. CIP/FIP Icing Severity (3,000 Feet MSL)-Example Icing severity at 3000 It. MSL Analysis valid 1500 UTC Mon 27 Nov 2006 terrain None Trace Light Moderate Heavy ø Negative WJ Trace-Light \ Light-Moderate I Moderate-Savere Icing PIREP Symbols W Trace Lyl Light / Moderate I/ Sevare 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. Brown regions indicate where higher-elevation terrain extends above the altitude of the particular graphic.
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5-151 Figure 5-80. CIP/FIP Icing Severity—Max Example
5.21.1.2.3 Icing Severity—Probability > 25 Percent.
The Icing Severity—Probability > 25 percent product depicts where at least a 26 percent probability exists for the indicated icing intensity. Icing intensity is displayed using icing intensity categories: trace, light, moderate, and heavy.
The product is available on https://www.aviationweather.gov in single altitudes, e.g., 3,000 ft MSL, or a composite of all altitudes from 1,000 ft MSL to FL300, i.e., max level.
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. 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 percent or less.
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5.21.1.2.4 Icing Severity—Probability > 50 Percent.
The Icing Severity—Probability > 50 percent product depicts where the probability of the indicated icing intensity is at least 51 percent. Icing intensity is displayed using icing intensity categories: trace, light, moderate, and heavy.
The product is available on https://www.aviationweather.gov in single altitudes, e.g., 3,000 ft MSL, or a composite of all altitudes from 1,000 ft MSL to FL300, i.e., max level.
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 percent or less.
5.21.1.2.5 Icing Severity Plus Supercooled Large Drops (SLD).
The Icing Severity plus SLD product depicts the intensity of icing expected as well as locations where a threat for SLD exists. The product is available on https://www.aviationweather.gov in single altitudes, e.g., 3,000 ft MSL (see Figure 5-81, CIP/FIP Icing Severity Plus Supercooled Large Drops (SLD)—Example), or a composite of all altitudes from 1,000 ft MSL to F L300, i.e., max level (see Figure 5-82, CIP/FIP Icing Severity Plus Supercooled Large Droplets (SLD)—M ax Example).
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 (14 CFR part 25 a ppendix C), can be particularly hazardous to some aircraft.
Icing intensity is displayed using icing intensity categories: trace, light, moderate, and heavy.
Figure 5-81. CIP/FIP Icing Severity Plus Supercooled Large Drops (SLD)-Example Icing severity at 3000 ft. MSL Analysis valid 1800 UTC Mon 27 Nov 2006 SLD threat terrain None Trace Light Moderate Hedyy es Negative L Trace-Light 1] Light-Moderate I Moderate-Severe cing PIREP Symbals W Trace Lyl Light ' Moderate '/ Severe 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. 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.
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5-154 Figure 5-82. CIP/FIP Icing Severity Plus Supercooled Large Droplets (SLD)—Max Example
5.21.1.3 St rengths and Limitations.
5.21.1.3.1 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.
5.21.1.3.2 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,
5-155 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.
5.21.1.4 Uses.
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.
The CIP/FIP Icing Severity product can be used to determine the intensity of icing. The CIP/FIP Icing Severity—Probability > 25 percent or Probability > 50 percent 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 ft of the graphic’s altitude and has been observed within 75 minutes of the chart’s valid time. On CIP/FIP max level product, PIREPs for all altitudes
(i.e., 1,000 feet MSL to FL300) are displayed except negative reports do not appear to reduce clutter. The PIREP legend is located on the bottom of each graphic.
5.21.2 Graphical Turbulence Guidance (GTG).
The GTG product suite provides a four-dimensional diagnosis and forecast of Non-Convective turbulence intensity (as indicated by the estimated energy dissipation to the 1/3 power–EDR in units of m2/3 s-1). GTG3 does not specifically predict turbulence associated with Convective clouds, or small-scale local terrain features, but does predict turbulence associated with upper-level clear and mountain wave sources.
Note: GTG3 is the third generation of the GTG product. Whereas the graphic examples in this paragraph state GTG3, this paragraph uses the general name of GTG in the description of the product.
The GTG is created using a combination of derived turbulence indicators from NCEP’s Weather Research and Forecasting (WRF) Rapid Refresh (RAP) NWP model. The GTG product suite, which consists of 0-, 1-, 2- 3-, 6-, 9-, 12-, and 18-hour forecasts, 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 CONUS, much of Canada and Mexico, and their respective coastal waters.
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5.21.2.1 Issuance.
The GTG pr oduct suite is issued and updated every hour by the AWC and is available through https://www.aviationweather.gov.
5.21.2.2 Content.
The GTG product (see Figure 5-83, GTG—Max Intensity Example CAT+MWT All Levels) can be viewed at single altitudes and FLs or as a composite of all altitudes from 10,000 ft MSL to FL450, which is referred to as a maximum or max (see Figure 5-84, CAT+MWT Low Levels Example (GA Users)). Single altitudes are referenced to MSL from 10,000 to 17,000 ft and FLs above 17,000 ft.
The AWC’s website allows for access to every other altitude (11,000 FT, 13,000 FT, 15,000 FT, etc.). However, vertical cross sections and presentation of all altitudes can be viewed using the Flight Path Tool (see paragraph 6.2) on https://www.aviationweather.gov. Gridded versions of these products are also delivered for users who wish to integrate GTG with flight pla nning systems or to view the output in their own graphical display systems.
Figure 5-83. GTG Max Intensity Example CAT+MWT All Levels Aircraft: Heavy • Plot: Combined * Vertical level: max Forecast time: Ohr - 15Z 03 Nov GTG - Max combined intensity (1000 ft. MSL to FL500) 00 hr forecast valid 1500 UTC Tue 03 Nov 2015 ADDE Eddy Dissipation Rate (EDR) _ Mod 10 20 30 40 50 60 70 80 90 Turb PIREP Symbols - - Smooth-Light @ Smooth A Light A Light-Moderate _A Moderate A Moderate-Sevara _M Severe * Extreme 5-157
Figure 5-84. CAT+MWT Low Levels Example (GA Users) Aircraft: Heavy • Plot: Combined • Vertical level: 5,000 Forecast time: 0hr - 15Z 03 Nov GTG - Combined CAT+MTW at 5000 ft. MSL 00 hr forecast valid 1500 UTC Tue 03 Nov 2015 Crestad by;
ADDE ' Eddy Dissipation Rate (EDR) terroin Mad Sev JE 10 20 30 40 50 60 70 80 90 Turb PIREP Symbols - - Smooth-Light @ Smooth A Light A Light-Moderate _A Moderate A Moderate-Savera A Severe * Extreme 5-158
Figure 5-85. Explicit MWT Forecasts Example Aircraft: Heavy • Plot: Mtn Wave • Vertical level: max Forecast time: Ohr - 152 03 Nov GTG - Max mountain wave (1000 ft. MSL to FL500) 00 hr forecast valid 1500 UTC Tue 03 Nov 2015 Eddy Dissipation Rate (EDR) Igt| _ Mod Sei 10 20 30 40 50 60 70 80 90 Turb PIREP Symbols - - Smooth-Light O Smooth A Light A Light-Moderate _A Moderate A Moderote-Savera _^ Severe * Extreme
5.21.2.3 Strengths and Limitations.
The GTG provides an hourly, high-resolution product of EDR at and above 10,000 ft MSL in 1,000-ft intervals. The product is based on an ensemble of 5-159