FIPs will continue to evolve over the coming years with increased model resolutions, additional horizontal layers, and improvements to the algorithms and/or data sets used to produce the products. Along with these improvements may come a change in references to the product update version. Users can find additional information on these products and any changes on the AWC’s “Icing” web page.

The FIP suite as it appears on the AWC’s website consists of three graphics, including:

The FIPs are generated for select altitudes from 1,000 ft MSL to FL300. FIPs are available at select forecast times through 18 hours.

The FIPs can be viewed at single altitudes and FLs or as a composite of all altitudes from 1,000 ft MSL to FL300, which is referred to as the “maximum” or “max.”

The FIP should be used in conjunction with the report and forecast information contained in an AIRMET and SIGMET.

The Icing Probability product displays the probability of icing at any level of intensity. Probabilities range from 0 percent (no icing expected) to 85 percent or greater (nearly certain icing). The product is available in single altitudes (e.g., 3,000 ft MSL) or a composite of all altitudes from 1,000 ft MSL to FL300.

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 in single altitudes (e.g., 17,000 ft MSL) or a composite of all altitudes from 1,000 ft MSL to FL300 (i.e., max level).

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 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).

SLD is defined as supercooled water droplets larger than 50 micrometers in diameter. These size droplets include freezing drizzle and/or freezing rain aloft.

Icing intensity is displayed using icing intensity categories: trace, light, moderate, and heavy.

The NWS produces a turbulence product that is derived from airborne turbulence observations and NWS model data with no forecaster modifications. This product is GTG.

GTG computes the results from more than 10 turbulence algorithms, then compares the results of each algorithm with turbulence observations from both PIREPs and AMDAR data to determine how well each algorithm matches reported turbulence conditions from these sources. GTG then weighs the results of this comparison to produce a single turbulence forecast. Note that the success of GTG is proportional to the number of PIREPs and AMDAR reports available to verify the algorithms. This means the accuracy of GTG improves during daylight hours and where there is more traffic making PIREPs and sending of AMDAR data. GTG produces its forecasts every hour. Currently, GTG has separate forecasts for each hour through the first three hours, followed by forecasts at three-hour intervals through 18 hours. GTG forecasts are available at select altitudes from 1,000 ft MSL through FL450. GTG forecasts are also scaled to three ICAO weight class sizes for aircraft, with light-sized aircraft being less than 15,500 lb, heavy-sized aircraft being more than 300,000 lb, and medium-sized in between.

GTG does not specifically predict turbulence associated with convective clouds or small-scale local terrain features, but it does predict turbulence associated with upper-level clear and mountain wave sources.

GTG provides three depictions of turbulence: