Closer Look: Graphical Forecasts for Aviation

Private Pilot License (PPL) Notes

This section provides an overview of the Graphical Forecasts for Aviation (GFA), an interactive tool that helps pilots review weather forecasts in a graphical form, essential for pre-flight planning and understanding aviation weather conditions.

Accessing the Graphical Forecasts for Aviation (GFA)

1. Visit the Aviation Weather Center website.
   1. You will see a big-picture view of the United States showing current weather hazards.
   2. This includes PIREPs, SIGMETs, and IFR conditions.
2. Select the option to launch the interactive Graphical Forecasts for Aviation map.
   1. The full-screen map shows current observations by default, including radar imagery, airport flight categories, PIREPs, and SIGMETs.

Using the GFA Map

1. Review METAR data visually depicted on the map.
   1. Shows current temperature, pressure, cloud coverage, flight category, visibility, and surface winds.
   2. Click on any report for more detailed information.
2. Use the time slider at the bottom to review reports over the past 18 hours.
   1. Helps assess weather trends over time.
3. Utilize the Flight Path function.
   1. Select the Flight Path icon from the top-right menu.
   2. Enter your route and set the highest altitude relevant to your flight.
   3. Select the "Cross-Section" option to view a profile of your flight, including temperature, wind speed, and turbulence.
   4. Draw your flight path on the map using the "Draw Path" option.
   5. Zoom in or out on specific flight segments using the "+" and "-" buttons or your mouse scroll wheel.
   6. Use the compass icon to quickly zoom to your current location.
4. Customize the map layers.
   1. Select the layers option from the menu to choose which weather products are displayed.
   2. Use the "Map Options" button for additional customizations.
      1. Change the basemap to a VFR or IFR chart.
5. Refer to the Legend.
   1. Located at the bottom right corner of the map.
   2. Displays a visual legend explaining weather symbols and graphics currently selected.

Navigating the Weather Menu

1. Find the main menu items at the top left: Weather, Products, Tools, and Connect.
   1. Focus on the Weather menu for accessing various forecast products.
2. Understand the options under the Weather menu:
   1. Observations: Shows current weather observations as default.
   2. Ceiling and Visibility: Displays forecasts of ceilings and visibilities.
      1. Use "Flight Categories" view for a big-picture of VFR and IFR conditions.
      2. Use "Active Layers" to focus on Ceiling or Visibility specifically.
      3. Verify the time slider matches your proposed flight time.
      4. Useful for IFR pilots to determine if an alternate airport is required when a TAF is unavailable.
   3. Clouds: Reviews forecast cloud coverage, tops, and bases.
      1. Select "Cloud Cover", "Top", or "Base" from "Active Layers".
      2. "Tops" view helps in selecting an altitude to get above clouds.
      3. Note: Based on the Rapid Refresh (RAP) model; predictions may struggle with convection, so use with caution.
   4. Precipitation: Displays weather hazards for a given time.
      1. Data comes from the National Digital Forecast Database (NDFD), a human-generated forecast.
   5. Thunderstorms: Shows forecast coverage of thunderstorms.
      1. Also uses data from NDFD.
   6. Winds: Shows wind forecasts at various altitudes.
      1. Use the vertical slider on the left to select the altitude relevant to your flight.
      2. "Max" setting displays the maximum wind speed sampled across all altitudes.
   7. Turbulence: Provides forecasts of turbulence intensity at selected altitudes.
      1. Based on the eddy dissipation rate.
   8. Icing: Displays icing severity forecasts.
      1. Indicates how intense icing would be if encountered at that altitude.
      2. Note: It shows the severity, not the probability of icing.

Remember, the Graphical Forecasts for Aviation (GFA) is an excellent tool to supplement your flight briefings. Make it a point to check it out before each flight to stay informed about weather conditions and ensure a safe flying experience.